U.S. patent application number 14/901738 was filed with the patent office on 2016-12-22 for monosubstituted diazabenzimidazole carbene metal complexes for use in organic light emitting diodes.
This patent application is currently assigned to BASF SE. The applicant listed for this patent is BASF SE. Invention is credited to Glauco BATTAGLIARIN, Korinna DORMANN, Thomas GE NER, Ute HEINEMEYER, Christian LENNARTZ, Flavio Luiz, Stefan METZ, Peter MURER, Gerhard WAGENBLAST, Soichi WATANABE.
Application Number | 20160372687 14/901738 |
Document ID | / |
Family ID | 48699683 |
Filed Date | 2016-12-22 |
United States Patent
Application |
20160372687 |
Kind Code |
A1 |
MURER; Peter ; et
al. |
December 22, 2016 |
MONOSUBSTITUTED DIAZABENZIMIDAZOLE CARBENE METAL COMPLEXES FOR USE
IN ORGANIC LIGHT EMITTING DIODES
Abstract
An organic electronic device, preferably an organic
light-emitting diode (OLED), comprising at least one metal-carbene
complex comprising one, two or three specific bidentate
diazabenzimidazole carbene ligands; a light-emitting layer
comprising said metal-carbene complex as emitter material,
preferably in combination with at least one host material; the use
of said metal-carbene complex in an OLED; an apparatus selected
from the group consisting of stationary visual display units,
mobile visual display units, illumination units, units in items of
clothing, units in handbags, units in accessories, units in
furniture and units in wallpaper comprising said organic electronic
device, preferably said OLED, or said light-emitting layer; the
metal-carbene complex comprising one, two or three specific
bidentate diazabenzimidazole carbene ligands mentioned above and a
process for the preparation of said metal-carbene complex.
Inventors: |
MURER; Peter; (Oberwil,
CH) ; DORMANN; Korinna; (Bad Durkheim, DE) ;
Luiz; Flavio; (Ludwigshafen, DE) ; BATTAGLIARIN;
Glauco; (Mannheim, DE) ; METZ; Stefan;
(Mannheim, DE) ; HEINEMEYER; Ute; (Neustadt,
DE) ; LENNARTZ; Christian; (Schifferstadt, DE)
; WAGENBLAST; Gerhard; (Wachenheim, DE) ;
WATANABE; Soichi; (Seoul, KR) ; GE NER; Thomas;
(Heidelberg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BASF SE |
Ludwigshafen |
|
DE |
|
|
Assignee: |
BASF SE
Ludwigshafen
DE
|
Family ID: |
48699683 |
Appl. No.: |
14/901738 |
Filed: |
July 2, 2014 |
PCT Filed: |
July 2, 2014 |
PCT NO: |
PCT/EP2014/064054 |
371 Date: |
December 29, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 2211/185 20130101;
C07F 15/0033 20130101; Y02E 10/549 20130101; C07F 15/0086 20130101;
H01L 51/5016 20130101; H01L 51/0087 20130101; C09B 57/10 20130101;
H01L 51/0085 20130101; C09K 11/06 20130101; C09B 57/00
20130101 |
International
Class: |
H01L 51/00 20060101
H01L051/00; C09K 11/06 20060101 C09K011/06; C07F 15/00 20060101
C07F015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 2, 2013 |
EP |
13174779.2 |
Claims
1.-16. (canceled)
17. An organic electronic device comprising at least one
metal-carbene complex, wherein the metal is Ir or Pt, comprising
one, two or three bidentate ligands of formula (I) and/or (I')
##STR00155## wherein R.sup.1 is a linear or branched alkyl radical
which is linked to the diazabenzimidazole carbene unit via a
sp.sup.3 hybridized carbon atom, selected from the group consisting
of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl;
A.sup.1 is CR.sup.2 or N; A.sup.2 is CR.sup.3 or N; A.sup.3 is
CR.sup.4 or N; A.sup.4 is CR.sup.5 or N; A.sup.1' is CR.sup.2 or N;
A.sup.2' is CR.sup.3' or N; A.sup.3' is CR.sup.4' or N; A.sup.4' is
CR.sup.5' or N; R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2',
R.sup.3', R.sup.4' and R.sup.5' are each independently hydrogen;
deuterium; a linear or branched, substituted or unsubstituted alkyl
radical having 1 to 20 carbon atoms, optionally interrupted by at
least one heteroatom, selected from the group consisting of O, S
and N; a substituted or unsubstituted cycloalkyl radical having a
total of from 3 to 30 carbon atoms; a substituted or unsubstituted
heterocycloalkyl radical, interrupted by at least one heteroatom
selected from the group consisting of O, S and N and having a total
of from 3 to 30 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical, having a total of from 6 to 30 carbon
atoms; a substituted or unsubstituted heteroaryl radical, having a
total of from 5 to 30 carbon atoms and/or heteroatoms, selected
from the group consisting of O, S and N; or a group with donor or
acceptor action; R.sup.9, R.sup.10, R.sup.11 are each independently
a linear or branched alkyl radical, having from 1 to 6 carbon
atoms; a substituted or unsubstituted aryl radical, having from 6
to 18 carbon atoms; a substituted or unsubstituted heteroaryl
radical, having a total of from 5 to 18 carbon atoms and/or
heteroatoms; a substituted or unsubstituted cycloalkyl radical
having a total of from 3 to 18 carbon atoms; or R.sup.2 and
R.sup.3, R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.2' and
R.sup.3', R.sup.3' and R.sup.4' or R.sup.4' and R.sup.5' form,
independently of each other, together with the carbon atoms to
which they are bonded, a saturated or unsaturated or aromatic ring,
which has a total of from 5 to 18 carbon atoms and/or heteroatoms;
.about. is the bonding site to the metal; whereby substituted aryl
means aryl substituted by one or more further radicals selected
from the group consisting of C.sub.1-C.sub.20-alkyl,
C.sub.6-C.sub.30-aryl and substituents with donor or acceptor
action; substituted heteroaryl means heteroaryl substituted at one,
more than one or all substitutable positions by radicals selected
from the group consisting of C.sub.1-C.sub.20-alkyl,
C.sub.6-C.sub.30-aryl and substituents with donor or acceptor
action; substituted alkyl, substituted cycloalkyl and substituted
heterocycloalkyl means alkyl, cycloalkyl and heterocycloalkyl
substituted by one or more substituents selected from the group
consisting of groups with donor or acceptor action, deuterium, a
substituted or unsubstituted cycloalkyl radical having a total of
from 3 to 30 carbon atoms, a substituted or unsubstituted
heterocycloalkyl radical, interrupted by at least one heteroatom,
selected from the group consisting of O, S and N, and having a
total of from 3 to 30 carbon atoms and/or heteroatoms, a
substituted or unsubstituted aryl radical, having a total of from 6
to 30 carbon atoms, or a substituted or an unsubstituted heteroaryl
radical, having a total of from 5 to 30 carbon atoms and/or
heteroatoms, selected from the group consisting of O, S and N; and
groups with donor or acceptor action are understood to mean the
following groups: C.sub.1-C.sub.20-alkoxy,
C.sub.6-C.sub.30-aryloxy, C.sub.1-C.sub.20-alkylthio,
C.sub.6-C.sub.30-arylthio, SiR.sup.32R.sup.33R.sup.34, halogen
radicals, halogenated C.sub.1-C.sub.20-alkyl radicals,
--CO(R.sup.32), --C.dbd.O(SR.sup.32), --C.dbd.O(OR.sup.32),
--OC.dbd.O(R.sup.32), --SC.dbd.O(R.sup.32), --NR.sup.32R.sup.33,
OH, pseudohalogen radicals, --C.dbd.O(NR.sup.32R.sup.33),
--NR.sup.32C.dbd.O (R.sup.33), --P(O) (OR.sup.32).sub.2, --OP(O)
(OR.sup.32).sub.2, --PR.sup.32R.sup.33, --P(O)R.sup.32.sub.2,
--OS(O).sub.2OR.sup.32, --S(O)R.sup.32, --S(O).sub.2OR.sup.32,
--S(O).sub.2R.sup.32, --S(O).sub.2NR.sup.32R.sup.33, NO.sub.2,
--OB(OR.sup.32).sub.2, --C.dbd.NR.sup.32R.sup.33), borane radicals,
stannate radicals, hydrazine radicals, hydrazone radicals, oxime
radicals, nitroso groups, diazo groups, vinyl groups, sulfoximines,
alanes, germanes, boroxines and borazines; R.sup.32, R.sup.33 and
R.sup.34 are each independently hydrogen, substituted or
unsubstituted C.sub.1-C.sub.20-alkyl or substituted or
unsubstituted C.sub.6-C.sub.30-aryl or substituted or unsubstituted
heteroaryl having 5 to 30 ring atoms.
18. The organic electronic device according to claim 16, wherein
the organic electronic device is selected from organic
light-emitting diodes (OLED), light-emitting electrochemical cells
(LEEC), organic photovoltaic cells (OPV) and organic field-effect
transistors (OFET).
19. The organic electronic device according to claim 16, wherein
the metal-carbene complex comprising one, two or three bidentate
ligands of formula (I) and/or (I') is employed as emitter material
in OLEDs or LEECs or absorption dye in OPVs.
20. The organic electronic device according to claim 18, wherein
the OLED comprises (a) an anode, (b) a cathode, (c) a
light-emitting layer between the anode and the cathode, wherein the
metal-carbene complex comprising one, two or three bidentate
ligands of formula (I) and/or (I') is present in the light-emitting
layer of the OLED.
21. The organic electronic device according to claim 16, wherein
the groups A.sup.1, A.sup.2, A.sup.3, A.sup.4, A.sup.1', A.sup.2',
A.sup.3' and A.sup.4' in the ligands of formulae (I) and (I') have
the following meanings: A.sup.1 is CR.sup.2; A.sup.2 is CR.sup.3;
A.sup.3 is CR.sup.4; A.sup.4 is CR.sup.5; A.sup.1' is CR.sup.2';
A.sup.2' is CR.sup.3'; A.sup.3' is CR.sup.4'; A.sup.4' is
CR.sup.5'; R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3',
R.sup.4' and R.sup.5' are each independently hydrogen; deuterium; a
linear or branched, substituted or unsubstituted alkyl radical
having 1 to 20 carbon atoms, optionally interrupted by at least one
heteroatom, selected from the group consisting of O, S and N; a
substituted or unsubstituted cycloalkyl radical, having a total of
from 3 to 10 carbon atoms; a substituted or unsubstituted
heterocycloalkyl radical, interrupted by at least one heteroatom,
selected from the group consisting of O, S and N, and having a
total of from 3 to 10 carbon atoms and/or heteroatoms; a group with
donor or acceptor action, selected from halogen radicals, CF.sub.3,
CN, SiPh.sub.3 and SiMe.sub.3; a substituted or unsubstituted aryl
radical, having from 6 to 30 carbon atoms.
22. The organic electronic device according to claim 16, wherein
the metal-carbene complex has one of the following formulae (II),
(II') or (II'') ##STR00156## wherein R.sup.1 is a linear or
branched alkyl radical which is linked to the diazabenzimidazole
carbene unit via a sp.sup.3 hybridized carbon atom, selected from
methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl;
A.sup.1 is CR.sup.2 or N; A.sup.2 is CR.sup.3 or N; A.sup.3 is
CR.sup.4 or N; A.sup.4 is CR.sup.5 or N; A.sup.1' is CR.sup.2' or
N; A.sup.2' is CR.sup.3' or N; A.sup.3' is CR.sup.4' or N; A.sup.4'
is CR.sup.5' or N; R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2',
R.sup.3', R.sup.4' and R.sup.5' are each independently hydrogen;
deuterium; a linear or branched, substituted or unsubstituted alkyl
radical having 1 to 20 carbon atoms, optionally interrupted by at
least one heteroatom, selected from the group consisting of O, S
and N; a substituted or unsubstituted cycloalkyl radical having a
total of from 3 to 30 carbon atom; a substituted or unsubstituted
heterocycloalkyl radical, interrupted by at least one heteroatom
selected from the group consisting of O, S and N and having a total
of from 3 to 30 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical, having a total of from 6 to 30 carbon
atoms; a substituted or unsubstituted heteroaryl radical, having a
total of from 5 to 30 carbon atoms and/or heteroatoms, selected
from the group consisting of O, S and N; or a group with donor or
acceptor action; R.sup.9, R.sup.10, R.sup.11 are each independently
a linear or branched alkyl radical, having from 1 to 6 carbon
atoms; a substituted or unsubstituted aryl radical, having from 6
to 18 carbon atoms; a substituted or unsubstituted heteroaryl
radical, having a total of from 5 to 18 carbon atoms and/or
heteroatoms; a substituted or unsubstituted cycloalkyl radical
having a total of from 3 to 18 carbon atoms; or R.sup.2 and
R.sup.3, R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.2' and
R.sup.3', R.sup.3' and R.sup.4' or R.sup.4' and R.sup.5' form,
independently of each other, together with the carbon atoms to
which they are bonded, a saturated or unsaturated or aromatic ring,
which has a total of from 5 to 18 carbon atoms and/or heteroatoms;
M is Ir; n is 1, 2 or 3; L is a monoanionic bidentate ligand, o is
0, 1 or 2, where, when o=2, the L ligands may be the same or
different; n' is 1 or 2; n'' is 1 or 2; wherein the sum of n'+n''
is 2 or 3; o' is 0 or 1; wherein the sum of n+o in formulae (II)
and (II') and the sum of n'+n''+o' in formula (II'') is 3, with the
proviso that n in formula (II) and (II') is at least 1 and n', as
well as n'' in formula (II'') are at least 1.
23. The organic electronic device according to claim 16, wherein
the metal-carbene complex has one of the following formulae (II),
(II') or (II'') ##STR00157## wherein R.sup.1 is a linear or
branched alkyl radical which is linked to the diazabenzimidazole
carbene unit via a sp.sup.3 hybridized carbon atom, selected from
methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl;
A.sup.1 is CR.sup.2 or N; A.sup.2 is CR.sup.3 or N; A.sup.3 is
CR.sup.4 or N; A.sup.4 is CR.sup.5 or N; A.sup.1' is CR.sup.2' or
N; A.sup.2' is CR.sup.3' or N; A.sup.3' is CR.sup.4' or N; A.sup.4'
is CR.sup.5' or N; R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2',
R.sup.3', R.sup.4' and R.sup.5' are each independently hydrogen;
deuterium; a linear or branched, substituted or unsubstituted alkyl
radical having 1 to 20 carbon atoms, optionally interrupted by at
least one heteroatom, selected from the group consisting of O, S
and N; a substituted or unsubstituted cycloalkyl radical having a
total of from 3 to 30 carbon atom; a substituted or unsubstituted
heterocycloalkyl radical, interrupted by at least one heteroatom
selected from the group consisting of O, S and N and having a total
of from 3 to 30 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical, having a total of from 6 to 30 carbon
atoms; a substituted or unsubstituted heteroaryl radical, having a
total of from 5 to 30 carbon atoms and/or heteroatoms, selected
from the group consisting of O, S and N; or a group with donor or
acceptor action; R.sup.9, R.sup.10, R.sup.11 are each independently
a linear or branched alkyl radical, having from 1 to 6 carbon
atoms; a substituted or unsubstituted aryl radical, having from 6
to 18 carbon atoms; a substituted or unsubstituted heteroaryl
radical, having a total of from 5 to 18 carbon atoms and/or
heteroatoms; a substituted or unsubstituted cycloalkyl radical
having a total of from 3 to 18 carbon atoms; or R.sup.2 and
R.sup.3, R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.2' and
R.sup.3', R.sup.3' and R.sup.4' or R.sup.4' and R.sup.5' form,
independently of each other, together with the carbon atoms to
which they are bonded, a saturated or unsaturated or aromatic ring,
which has a total of from 5 to 18 carbon atoms and/or heteroatoms;
M is Pt; n is Pt 1 or 2; L is a monoanionic bidentate ligand, o is
0 or 1; n' is 1; n'' is 1; wherein the sum of n'+n'' is 2; o' is 0;
wherein the sum of n+o in formulae (II) and (II') and the sum of
n'+n''+o' in formula (II'') is 2, with the proviso that n in
formula (II) and (II') is at least 1 and n', as well as n'' in
formula (II'') are both 1.
24. The organic electronic device according to claim 21, wherein n
is 3; n' is 1 or 2, n'' is 1 or 2, wherein the sum of n'+n'' is
3.
25. The organic electronic device according to claim 16, wherein
the monoanionic bidentate ligand L in the metal-carbene complex has
following meaning: a ligand of formula (A) ##STR00158## in which
R.sup.51 is in each case independently a linear or branched alkyl
radical having 1 to 6 carbons atoms; a substituted or unsubstituted
aryl radical having 6 to 18 carbon atoms; a substituted or
unsubstituted heteroaryl radical having a total of 5 to 18 carbon
atoms and/or heteroatoms, R.sup.52 is hydrogen; a linear or
branched alkyl radical having 1 to 6 carbon atoms; a substituted or
unsubstituted aryl radical having 6 to 18 carbon atoms; or L is a
carbene ligand of the general formula (B) ##STR00159## where
A.sup.9' is CR.sup.12' or N; A.sup.10' is CR.sup.13' or N;
R.sup.11' is a linear or branched, substituted or unsubstituted
alkyl radical having 1 to 20 carbon atoms, optionally interrupted
by at least one heteroatom, selected from O, S and N; a substituted
or unsubstituted cycloalkyl radical having 3 to 18 carbon atoms; a
substituted or unsubstituted heterocycloalkyl radical interrupted
by at least one heteroatom, selected from the group consisting of
O, S and N, and having 3 to 18 carbon atoms and/or heteroatoms; a
substituted or unsubstituted aryl radical having 6 to 30 carbon
atoms, a substituted or unsubstituted heteroaryl radical
interrupted by at least one heteroatom, selected from the group
consisting of O, S and N and having a total of 5 to 30 carbon atoms
and/or heteroatoms; R.sup.12', R.sup.13' are each independently
hydrogen; deuterium; a linear or branched, substituted or
unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally
interrupted by at least one heteroatom, selected from the group
consisting of O, S and N; a substituted or unsubstituted cycloalkyl
radical having 3 to 18 carbon atoms; a substituted or unsubstituted
heterocycloalkyl radical interrupted by at least one heteroatom,
selected from O, S and N, and having 3 to 18 carbon atoms and/or
heteroatoms; a substituted or unsubstituted aryl radical having 6
to 30 carbon atoms; a substituted or unsubstituted heteroaryl
radical interrupted by at least one heteroatom, selected from the
group consisting of O, S and N and having a total of 5 to 30 carbon
atoms and/or heteroatoms; or a group with donor or acceptor action;
if A.sup.9' is CR.sup.12' and A.sup.10' is CR.sup.13', CR.sup.12'
and CR.sup.13' together may form a saturated or unsaturated or
aromatic ring, which has a total of from 5 to 18 carbon atoms
and/or heteroatoms; A.sup.5' is CR.sup.14' or N; A.sup.6' is
CR.sup.15' or N; A.sup.7' is CR.sup.16' or N; A.sup.8' is
CR.sup.17' or N; R.sup.14', R.sup.15', R.sup.16', R.sup.17' are
each independently hydrogen; deuterium; a linear or branched,
substituted or unsubstituted alkyl radical having 1 to 20 carbon
atoms, optionally interrupted by at least one heteroatom, selected
from the group consisting of O, S and N; a substituted or
unsubstituted cycloalkyl radical having 3 to 18 carbon atoms; a
substituted or unsubstituted heterocycloalkyl radical interrupted
by at least one heteroatom, selected from the group consisting of
O, S and N, and having 3 to 18 carbon atoms and/or heteroatoms; a
substituted or unsubstituted aryl radical having 6 to 30 carbon
atoms; a substituted or unsubstituted heteroaryl radical
interrupted by at least one heteroatom, selected from the group
consisting of O, S and N and having a total of 5 to 30 carbon atoms
and/or heteroatoms; or a group with donor or acceptor action; or
R.sup.14' and R.sup.15', R.sup.15' and R.sup.16' or R.sup.16' and
R.sup.17' form, together with the carbon atoms to which they are
bonded, a saturated or unsaturated or aromatic ring, which has a
total of from 5 to 18 carbon atoms and/or heteroatoms; or if
A.sup.9' is CR.sup.12', R.sup.12' and R.sup.17' together may form a
saturated or unsaturated, linear or branched bridge optionally
comprising heteroatoms, selected from the group consisting of O, S
and N, to which is optionally fused a five- to eight-membered ring
comprising carbon atoms and/or heteroatoms, and which are
optionally substituted with aromatic units, heteroaromatic units or
groups with donor or acceptor action; q' is 0 or 1; or L is a
ligand of the general formula (C) ##STR00160## in which the symbols
are each defined as follows: D are each independently CR.sup.34'''
or N; W is C or N; E are each independently CR.sup.35''', N,
NR.sup.36''' or O; 1 is 1 or 2; R.sup.34''', R.sup.35''',
R.sup.36''' are each independently hydrogen; substituted or
unsubstituted or branched alkyl; substituted or unsubstituted aryl
or substituted or unsubstituted heteroaryl; or in each case two
R.sup.34''', R.sup.3''' or R.sup.36''' radicals together form a
fused ring which may optionally comprise at least one heteroatom;
or R.sup.34''', R.sup.35''', R.sup.36''' or R.sup.37''' a radical
having donor or acceptor action; where the line means an optional
bridge between one of the D groups and one of the E groups; where
the bridge may be defined as follows: alkylene, arylene,
heteroarylene, alkynylene, alkenylene, NR.sup.38''', O, S,
SiR.sup.41'''R.sup.42''', and (CR.sup.43'''R.sup.44''').sub.v,
where one or more nonadjacent (CR.sup.43'''R.sup.44''') groups may
be replaced by NR.sup.38''', O, S, SiR.sup.41'''R.sup.42''', where
v is from 2 to 10; and R.sup.38''', R.sup.41''', R.sup.42''',
R.sup.43''', R.sup.44''' are each H, alkyl, aryl or heteroaryl.
26. The organic electronic device according to claim 16, wherein
the metal-carbene complex is employed in combination with at least
one host material.
27. A light-emitting layer comprising at least one metal-carbene
complex as defined in claim 16 as emitter material.
28. An apparatus selected from the group consisting of stationary
visual display units; mobile visual display units; illumination
units; units in items of clothing; units in handbags, units in
accessories, units in furniture and units in wallpaper, comprising
the organic electronic device according to claim 16.
29. Metal-carbene complex, wherein the metal is Ir or Pt,
comprising one, two or three bidentate ligands of formula (I)
and/or (I') as described in claim 16.
30. A process for preparing a metal carbene complex according to
claim 28, by contacting suitable compounds comprising Ir or Pt
selected from the group consisting of [Ir(COD)Cl].sub.2,
[Ir(COE).sub.2Cl].sub.2 IrCl.sub.3.times.H.sub.2O, Ir(acac).sub.3,
Ir(COD).sub.2BF.sub.4, Ir(COD).sub.2BARF
(BARF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate)),
Pt(COD)Cl.sub.2, Pt(acac).sub.2,
[Pt(C.sub.6H.sub.10)Cl.sub.2].sub.2, K.sub.2PtCl.sub.6,
Pt(pyridine).sub.2Cl.sub.2, [PtMe.sub.2(SMe.sub.2)].sub.2,
Pt(SMe.sub.2).sub.2Cl.sub.2, Pt(SEt.sub.2).sub.2Cl.sub.2,
Pt(phenanthroline)Cl.sub.2, Pt(NH.sub.3).sub.2Cl.sub.2 and mixtures
thereof with ligand precursors of formula (IV), wherein the ligand
precursors are reacted with the suitable Ir or Pt comprising
compounds and the carbene can be released from precursors of the
carbene ligands by removing methanol or ethanol, wherein the ligand
precursor used is a compound of the general formula (IV)
##STR00161## wherein R.sup.1, A.sup.1, A.sup.2, A.sup.3, A.sup.4,
A.sup.1', A.sup.2', A.sup.3' and A.sup.4' are each as already
defined in claim 16, and R.sup.12 is defined as follows: R.sup.12
is independently SiR.sup.13R.sup.14R.sup.15, aryl, heteroaryl,
alkyl, cycloalkyl or heterocycloalkyl, R.sup.13, R.sup.14, R.sup.15
are each independently aryl, heteroaryl, alkyl, cycloalkyl or
heterocycloalkyl.
31. An apparatus selected from the group consisting of stationary
visual display units; mobile visual display units; illumination
units; units in items of clothing; units in handbags, units in
accessories, units in furniture and units in wallpaper comprising
the light-emitting layer according to claim 26.
Description
[0001] The present invention relates to an organic electronic
device, preferably an organic light-emitting diode (OLED),
comprising at least one metal-carbene complex comprising one, two
or three specific bidentate diazabenzimidazole carbene ligands, to
a light-emitting layer comprising said metal-carbene complex as
emitter material, preferably in combination with at least one host
material, to the use of said metal-carbene complex in an OLED and
to an apparatus selected from the group consisting of stationary
visual display units, mobile visual display units, illumination
units, units in items of clothing, units in handbags, units in
accessories, units in furniture and units in wallpaper comprising
said organic electronic device, preferably said OLED, or said
light-emitting layer. The present invention further relates to the
metal-carbene complex comprising one, two or three specific
bidentate diazabenzimidazole carbene ligands mentioned above and to
a process for the preparation of said metal-carbene complex.
[0002] Organic electronics, i.e. organic electronic devices, are an
important sector in the field of electronics. Organic electronics
is a subfield of electronics which uses electronic circuits which
comprise polymers or smaller organic compounds. Fields of use of
organic electronics are the use of polymers or smaller organic
compounds in organic electronic devices, for example in organic
light-emitting diodes (OLED), light-emitting electrochemical cells
(LEEC), organic photovoltaic cells (OPV) and organic field-effect
transistors (OFET).
[0003] The use of suitable novel organic materials thus allows
various new types of components based on organic electronics to be
provided, such as displays, illumination, sensors, transistors,
data stores or photovoltaic cells. This makes possible the
development of new devices which are thin, light, flexible and
producible at low cost.
[0004] The synthesis and provision of new materials for organic
electronic devices is therefore an important research topic.
Especially the synthesis and provision of dyes for use in organic
electronic devices (useful for example as emitter materials in
OLEDs and LEECs or as absorption dyes in OPVs is important for
providing organic electronic devices having good stabilities and
long lifetimes as well as--in the case of OLEDs and LEECs--high
quantum efficiencies.
[0005] A preferred field of use according to the present
application is the use of relatively small organic compounds in
organic light-emitting diodes (OLED). OLEDs exploit the propensity
of materials to emit light when they are excited by electrical
current. OLEDs are of particular interest as an alternative to
cathode ray tubes and liquid-crystal displays for production of
flat visual display units. Owing to the very compact design and the
intrinsically low power consumption, devices comprising OLEDs are
suitable especially for mobile applications, for example for
applications in cellphones, smartphones, digital cameras, mp3
players, tablet computers, laptops, etc. In addition, white OLEDs
give great advantage over the illumination technologies known to
date, especially a particularly high efficiency.
[0006] The basic principles of the way in which OLEDs work and
suitable structures (layers) of OLEDs are specified, for example,
in WO 2005/113704 and the literature cited therein.
[0007] The light-emitting materials (emitters) used may, as well as
fluorescent materials (fluorescent emitters), be phosphorescent
materials (phosphorescent emitters). The phosphorescent emitters
are typically organometallic complexes which, in contrast to the
fluorescence emitters which exhibit singlet emission, exhibit
triplet emission (M. A. Baldow et al., Appl. Phys. Lett. 1999, 75,
4 to 6). For quantum-mechanical reasons, when the phosphorescent
emitters are used, up to four times the quantum efficiency, energy
efficiency and power efficiency is possible.
[0008] Of particular interest are organic light-emitting diodes
with a good color purity, low operational voltage, high efficiency,
high efficacy, high resistance to thermal stress and long
operational lifetime.
[0009] In order to implement the aforementioned properties in
practice, it is necessary to provide suitable emitter materials.
The selection of suitable emitter materials has a significant
influence on parameters including the color purity, efficiency,
lifetime and operating voltages of the OLEDs.
[0010] The prior art proposes numerous different emitter materials
for use in OLEDs.
[0011] The use of metal-carbene complexes comprising
diazabenzimidazole carbene ligands has only been described in a few
prior art references.
[0012] WO 2012/121936 A2 compounds comprising a diazabenzimidazole
carbene ligand and a device comprising an organic light-emitting
device which comprise such compounds. However, no specific
monoalkyl substitution of the diazabenzimidazole carbene ligands
and the superiority of compounds comprising such a specific
monoalkyl substitution are mentioned in WO 2012/121936 A2.
[0013] WO 2009/046266 A1 discloses an emissive phosphorescent
material for use in OLEDs which comprise at least one tridentate
ligand bound to a metal center, wherein at least one of the bonds
to the tridentate ligand is a carbon-metal bond. The tridentate
ligand may be based on a diazabenimidazole carbene. However, WO
2009/046266 A1 exclusively concerns metal complexes comprising at
least one tridentate ligand. Further, there is no information in WO
2009/046266 A1 concerning the superiority of metal complexes
comprising tridentate ligands based on a diazabenimidazole carbene.
Further, no specific substitution of the tridentate ligand which
may be based on a diazabenimidazole carbene is mentioned in WO
2009/046266 A1.
[0014] WO 2011/073149 A1 discloses metal-carbene complexes
comprising a central atom selected from iridium and platinum and
diazabenzimidazole carbene ligands and OLEDs (Organic
Light-Emitting Diodes) which comprise such complexes. However, no
specific monoalkyl substitution of the diazabenzimidazole carbene
ligands and the superiority of complexes comprising such a specific
monoalkyl substitution are mentioned in WO 2011/073149 A1.
[0015] US 2012/0305894 A1 relates to a blue phosphorescent compound
with a high color purity and a high efficiency and an organic
electroluminescent device using the same. The blue phosphorescent
compound according to US 2012/0305894 A1 is characterized by the
following formula:
##STR00001##
wherein X is selected from nitrogen (N), oxygen (O), phosphorous
(P) and sulfur (S) atoms; and at least one of A1, A2, A3 and A4 is
nitrogen (N), and the remaining are selected from hydrogen
(H)-substituted carbon, and an alkyl- or alkoxy-substituted carbon.
However, no specific monoalkyl substitution of diazabenzimidazole
carbene ligands and the superiority of complexes comprising such a
specific monoalkyl substitution are mentioned in US 2012/0305894
A1.
[0016] It is an object of the present invention to provide organic
electronic devices, preferably OLEDs, having--compared with the
organic electronic devices known in the art--a high color purity in
the blue region of the visible electromagnetic spectrum, a high
efficiency and a short emission lifetime.
[0017] This object is achieved by an organic electronic device,
preferably an OLED, comprising at least one metal-carbene complex,
wherein the metal is Ir or Pt, comprising one, two or three
bidentate ligands of formula (I) and/or (I')
##STR00002##
wherein
R.sup.1
[0018] is a linear or branched alkyl radical having 1 to 20 carbon
atoms, which is linked to the diazabenzimidazole carbene unit via a
sp.sup.3 hybridized carbon atom, optionally interrupted by at least
one heteroatom, selected from O, S and N, optionally substituted
with at least one of the following groups: a group with donor or
acceptor action; deuterium; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 30 carbon atoms; a
substituted or unsubstituted heterocyclo alkyl radical, interrupted
by at least one heteroatom, selected from O, S and N, and having a
total of from 3 to 30 carbon atoms and/or heteroatoms; a
substituted or unsubstituted aryl radical, having a total of from 6
to 30 carbon atoms; or a substituted or an unsubstituted heteroaryl
radical, having a total of from 5 to 30 carbon atoms and/or
heteroatoms, selected from O, S and N; a cycloalkyl radical having
a total of from 4 to 30 carbon atoms, optionally substituted by a
linear or branched, substituted or unsubstituted alkyl radical,
optionally interrupted by at least one heteroatom, selected from O,
S and N, and/or at least one of the groups mentioned above
concerning the linear or branched alkyl radical; or a heterocyclo
alkyl radical, which is linked to the diazabenzimidazole carbene
unit via a sp.sup.3 hybridized carbon atom, interrupted by at least
one heteroatom, selected from O, S and N, and having a total of
from 3 to 30 carbon atoms and/or heteroatoms, optionally
substituted by a linear or branched, substituted or unsubstituted
alkyl radical, optionally interrupted by at least one heteroatom,
selected from O, S and N, and/or at least one of the groups
mentioned above concerning the linear or branched alkyl radical; A1
is CR.sup.2 or N; preferably CR.sup.2; A.sup.2 is CR.sup.3 or N;
preferably CR.sup.3; A.sup.3 is CR.sup.4 or N; preferably CR.sup.4;
A.sup.4 is CR.sup.5 or N; preferably CR.sup.5; A.sup.1' is
CR.sup.2' or N; preferably CR.sup.2'; A.sup.2' is CR.sup.3' or N;
preferably CR.sup.3'; A.sup.3' is CR.sup.4' or N; preferably
CR.sup.4'; A.sup.4' is CR.sup.5' or N; preferably CR.sup.5';
R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3', R.sup.4'
and R.sup.5' are each independently hydrogen; deuterium; a linear
or branched, substituted or unsubstituted alkyl radical having 1 to
20 carbon atoms, optionally interrupted by at least one heteroatom,
selected from O, S and N; a substituted or unsubstituted cycloalkyl
radical having a total of from 3 to 30 carbon atom; a substituted
or unsubstituted heterocyclo alkyl radical, interrupted by at least
one heteroatom selected from O, S and N and having a total of from
3 to 30 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical, having a total of from 6 to 30 carbon
atoms; a substituted or unsubstituted heteroaryl radical, having a
total of from 5 to 30 carbon atoms and/or heteroatoms, selected
from O, S and N; or a group with donor or acceptor action;
preferably, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3',
R.sup.4' and R.sup.5' are each independently hydrogen, deuterium, a
linear or branched, substituted or unsubstituted alkyl radical,
having 1 to 20 carbon atoms; an unsubstituted aryl radical, having
from 6 to 18 carbon atoms, a monosubstituted aryl radical having
from 6 to 18 carbon atoms, a disubstituted aryl radical having from
6 to 18 carbon atoms; an unsubstituted heteroaryl radical, having a
total of from 5 to 18 carbon atoms and/or heteroatoms, a
monosubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms, a disubstituted heteroaryl
radical, having a total of from 5 to 18 carbon atoms and/or
heteroatoms; more preferably, the aryl radical or heteroaryl
radical are selected from the group consisting of phenyl, tolyl,
xylyl, diisopropylphenyl, pyridyl, methylpyridyl, pyrimidyl,
pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl,
fluorenyl, dimethylfluorenyl, indolyl, methylindolyl, benzofuranyl
and benzothiophenyl; a group with donor or acceptor action,
selected from halogen radicals, preferably F or Cl, more preferably
F; CF.sub.3, CN; or SiR.sup.9R.sup.10R.sup.11, preferably
SiMe.sub.3, SiPh.sub.3, SiEt.sub.3 or SiPh.sub.2tBu; R.sup.9,
R.sup.10, R.sup.11 are each independently a linear or branched
alkyl radical, having from 1 to 6 carbon atoms, preferably methyl,
ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl or
iso-butyl; a substituted or unsubstituted aryl radical, having from
6 to 18 carbon atoms, preferably phenyl or tolyl; a substituted or
unsubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 18 carbon atoms,
preferably cyclopentyl or cyclohexyl; or R.sup.2 and R.sup.3,
R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.2' and
R.sup.3', R.sup.3' and R.sup.4' or R.sup.4' and R.sup.5' may form,
independently of each other, together with the carbon atoms to
which they are bonded, a saturated or unsaturated or aromatic,
optionally substituted ring, which is optionally interrupted by at
least one heteroatom, selected from O, S and N, has a total of from
5 to 18 carbon atoms and/or heteroatoms, and may optionally be
fused to at least one further optionally substituted saturated or
unsaturated or aromatic ring, optionally interrupted by at least
one heteroatom, selected from 0, S and N, and having a total of
from 5 to 18 carbon atoms and/or heteroatoms; .about. is the
bonding site to the metal.
[0019] It has been found by the inventors of the present invention
that organic electronic devices, preferably OLEDs, having--compared
with the organic electronic devices known in the art--a high color
purity in the blue region of the visible electromagnetic spectrum,
a high efficiency, a high luminous efficacy, low voltage and a
short emission lifetime are obtained by employing the metal-carbene
complex comprising one, two or three, preferably three, bidentate
ligands of formula (I) and/or (I') as mentioned above in the
organic electronic device, preferably the OLED, preferably as
emitter material.
[0020] The specific metal-carbene complexes comprising one, two or
three, preferably three, bidentate ligands of formula (I) and/or
(I') as mentioned above are characterized by the feature that said
complexes are monoalkyl substituted. It has been found by the
inventors that said monoalkyl substitution of the
diazabenzimidazole carbene ligand provides metal-carbene emitter
materials emitting blue light having a high color purity.
Additionally, the emission lifetime of said complexes is short and
the quantum yields are high to very high. Devices comprising the
complexes according to the present invention show high efficiency
and luminous efficacy as well as low voltage.
[0021] Because of the short emission lifetime, for example the
effects of triplet-triplet annihilation and self-quenching can be
suppressed and the device lifetime is improved.
[0022] It has further been found by the inventors of the present
invention that OLEDs comprising the metal-carbene complex
comprising one, two or three, preferably three, bidentate ligands
of formula (I) and/or (I') as mentioned above in an organic
electronic device, preferably in an OLED, especially as an emitter
material in an OLED, show high quantum efficiencies, high luminous
efficacy, low voltage and/or good stabilities and long
lifetimes.
[0023] The complexes are particularly suitable as emitter materials
for OLEDs showing electroluminescence in the blue region (CIEy
<0.40), more particularly in the deeper blue region (CIEy
<0.30, preferably CIEy <0.25), of the electromagnetic
spectrum, which enables, for example, the production of full-color
displays and white OLEDs.
[0024] In the context of the present invention, the terms aryl
radical, unit or group, heteroaryl radical, unit or group, alkyl
radical, unit or group, cycloalkyl radical, unit or group,
cycloheteroalkyl radical, unit or group, and groups with donor or
acceptor action are each defined as follows--unless stated
otherwise:
[0025] In the aryl radicals, heteroaryl radicals, alkyl radicals,
cycloalkyl radicals, cycloheteroalkyl radicals and groups with
donor or acceptor action mentioned below, one or more hydrogen
atoms (if present) may be substituted by deuterium atoms.
[0026] Aryl radicals or substituted or unsubstituted aryl radicals
having 6 to 30, preferably 6 to 18 carbon atoms
(C.sub.6-C.sub.30-aryl radicals) refer in the present invention to
radicals which are derived from monocyclic, bicyclic or tricyclic
aromatics which do not comprise any ring heteroatoms. When the
systems are not monocyclic systems, the term "aryl" for the second
ring also includes the saturated form (perhydro form) or the partly
unsaturated form (for example the dihydro form or tetrahydro form),
provided that the particular forms are known and stable. This means
that the term "aryl" in the present invention encompasses, for
example, also bicyclic or tricyclic radicals in which either both
or all three radicals are aromatic, and bicyclic or tricyclic
radicals in which only one ring is aromatic, and also tricyclic
radicals in which two rings are aromatic. Examples of aryl are:
phenyl, naphthyl, indanyl, 1,2-dihydronaphthenyl,
1,4-dihydronaphthenyl, indenyl, anthracenyl, phenanthrenyl or
1,2,3,4-tetrahydronaphthyl. Particular preference is given to
C.sub.6-C.sub.10-aryl radicals, for example phenyl or naphthyl,
very particular preference to C.sub.6-aryl radicals, for example
phenyl.
[0027] The aryl radicals or C.sub.6-C.sub.30-aryl radicals may be
unsubstituted or substituted by one or more further radicals.
Suitable further radicals are selected from the group consisting of
C.sub.1-C.sub.20-alkyl, C.sub.6-C.sub.30-aryl and substituents with
donor or acceptor action, suitable substituents with donor or
acceptor action are specified below. The C.sub.6-C.sub.30-aryl
radicals are preferably unsubstituted or substituted by one or more
C.sub.1-C.sub.20-alkyl groups, C.sub.1-C.sub.20-alkoxy groups, CN,
CF.sub.3, F, SiMe.sub.3, SiPh.sub.3 or amino groups
(NR.sup.32R.sup.33 where suitable R.sup.32 and R.sup.33 radicals
are specified below), more preferably unsubstituted (e.g.
C.sub.6H.sub.5), o-monosubstituted (e.g. tolyl) or
o,o'-disubstituted by one respectively two C.sub.1-C.sub.20-alkyl
groups (e.g. xylyl), C.sub.1-C.sub.20-alkoxy groups, CN, CF.sub.3,
F, SiMe.sub.3, SiPh.sub.3 or amino groups (NR.sup.32R.sup.33 where
suitable R.sup.32 and R.sup.33 radicals are specified below).
[0028] Heteroaryl radicals or substituted or unsubstituted
heteroaryl radicals having a total of 5 to 30, preferably 5 to 18
carbon atoms and/or heteroatoms are understood to mean monocyclic,
bicyclic or tricyclic heteroaromatics, some of which can be derived
from the aforementioned aryl, in which at least one carbon atom in
the aryl base structure has been replaced by a heteroatom.
Preferred heteroatoms are N, O and S. The heteroaryl radicals more
preferably have 5 to 13 ring atoms. The base structure of the
heteroaryl radicals is especially preferably selected from systems
such as pyridine, pyrimidine and pyrazine and five-membered
heteroaromatics such as thiophene, pyrrole, imidazole, thiazole,
oxazole or furan. These base structures may optionally be fused to
one or two six-membered aromatic radicals. Suitable fused
heteroaromatics are carbazolyl, benzimidazolyl, benzofuryl,
benzothiazolyl, benzoxazolyl, dibenzofuryl, dibenzothiophenyl or
benzimidazo[1,2-a]benzimidazolyl.
[0029] The base structure may be substituted at one, more than one
or all substitutable positions, suitable substituents being the
same as those already specified under the definition of
C.sub.6-C.sub.30-aryl. However, the heteroaryl radicals are
preferably unsubstituted, o-monosubstituted or o,o'-disubstituted
by one respectively two C.sub.1-C.sub.20-alkyl groups,
C.sub.1-C.sub.20-alkoxy groups, CN, CF.sub.3, F, SiMe.sub.3,
SiPh.sub.3 or amino groups (NR.sup.32R.sup.33 where suitable
R.sup.32 and R.sup.33 radicals are specified below). Suitable
heteroaryl radicals are, for example, pyridin-2-yl, pyridin-3-yl,
pyridin-4-yl, pyrimidin-3-yl, pyrazin-2-yl, pyrazin-3-yl,
thiophen-2-yl, thiophen-3-yl, pyrrol-2-yl, pyrrol-3-yl, furan-2-yl,
furan-3-yl, thiazol-2-yl, oxazol-2-yl and imidazol-2-yl, and the
corresponding benzofused radicals, especially carbazolyl,
benzimidazolyl, benzofuryl, benzothiazole, benzoxazole,
dibenzofuryl or dibenzothiophenyl.
[0030] An alkyl radical in the context of the present application
is a linear or branched alkyl radical, optionally interrupted by at
least one heteroatom, and having 1 to 20 carbon atoms. Preference
is given to C.sub.1- to C.sub.10-alkyl radicals, particular
preference to C.sub.1- to C.sub.6-alkyl radicals. In the case of
R.sup.1, the alkyl radical is linked to the diazabenzimidazole
carbene unit via a sp.sup.3 hybridized carbon atom, in the case of
all other alkyl radicals, it is preferred that the alkyl radical is
linked via a sp.sup.3 hybridized carbon atom to the base unit. In
addition, the alkyl radicals may be unsubstituted or substituted by
one or more substituents. Preferred substituents are selected from
the group consisting of groups with donor or acceptor action,
preferably C.sub.1-C.sub.20-alkoxy, halogen, more preferably F,
C.sub.1-C.sub.20-haloalkyl, e.g. CF.sub.3; deuterium; a substituted
or unsubstituted cycloalkyl radical having a total of from 3 to 30
carbon atoms; a substituted or unsubstituted heterocyclo alkyl
radical, interrupted by at least one heteroatom, selected from O, S
and N, and having a total of from 3 to 30 carbon atoms and/or
heteroatoms; a substituted or unsubstituted aryl radical, having a
total of from 6 to 30 carbon atoms; or a substituted or an
unsubstituted heteroaryl radical, having a total of from 5 to 30
carbon atoms and/or heteroatoms, selected from O, S and N. Suitable
aryl substituents are specified above and suitable alkoxy and
halogen substituents are specified below. Examples of suitable
alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl,
heptyl and octyl, and also C.sub.1-C.sub.20-haloalkyl-,
C.sub.6-C.sub.30-aryl-, C.sub.1-C.sub.20-alkoxy- and/or
halogen-substituted, especially F-substituted, derivatives of the
alkyl groups mentioned, for example CF.sub.3 or CF.sub.2CF.sub.3.
This comprises both the n-isomers of the radicals mentioned and
branched isomers such as isopropyl, isobutyl, isopentyl, sec-butyl,
tert-butyl, iso-butyl, neopentyl, 3,3-dimethylbutyl, 3-ethylhexyl,
etc. Preferred alkyl groups are methyl, ethyl, isopropyl,
sec-butyl, tert-butyl, CF.sub.3 and CF.sub.2CF.sub.3.
[0031] A cycloalkyl radical or a substituted or unsubstituted
cycloalkyl radical having 3 to 30 carbon atoms is understood in the
context of the present application to mean a substituted or
unsubstituted C.sub.3-C.sub.30-cycloalkyl radical. Preferred are
cycloalkyl radicals having 5 to 18, more preferably 5 to 10 and
most preferably 5 to 8 carbon atoms in the base structure (ring) to
understand. Suitable substituents are the substituents mentioned
for the alkyl groups. Examples of suitable cycloalkyl groups, which
may be unsubstituted or substituted by the radicals mentioned above
for the alkyl groups, are cyclopentyl, cyclohexyl, cycloheptyl,
cyclooctyl, cyclononyl and cyclodecyl. They may also be polycyclic
ring systems such as decalinyl, norbornyl, bornanyl or
adamantyl.
[0032] A heterocycloalkyl radical or a substituted or unsubstituted
heterocycloalkyl radical having 3 to 30 carbon atoms and/or
heteroatoms is understood to mean heterocyclo-alkyl radicals having
3 to 18, preferably 5 to 10 and more preferably 5 to 8 ring atoms,
where at least one carbon atom in the heterocycloalkyl base
structure has been replaced by a heteroatom. Preferred heteroatoms
are N, O and S. Suitable substituents are the substituents
mentioned for the alkyl groups. Examples of suitable
heterocycloalkyl groups, which may be unsubstituted or substituted
by the radicals mentioned above for the alkyl groups, are radicals
derived from the following heterocycles: pyrrolidine, thiolane,
tetrahydrofuran, 1,2-oxathiolane, oxazolidine, piperidine, thiane,
oxane, dioxane, 1,3-dithiane, morpholine, piperazine. They may also
be polycyclic ring systems.
[0033] Suitable alkoxy radicals and alkylthio radicals derive
correspondingly from the aforementioned alkyl radicals. Examples
here include OCH.sub.3, OC.sub.2H.sub.5, OC.sub.3H.sub.7,
OC.sub.4H.sub.9 and OC.sub.8H.sub.17, and also SCH.sub.3,
SC.sub.2H.sub.5, SC.sub.3H.sub.7, SC.sub.4H.sub.9 and
SC.sub.8H.sub.17. In this context, C.sub.3H.sub.7, C.sub.4H.sub.9
and C.sub.8H.sub.17 comprise both the n-isomers and branched
isomers such as isopropyl, isobutyl, sec-butyl, tert-butyl and
2-ethylhexyl. Particularly preferred alkoxy or alkylthio groups are
methoxy, ethoxy, n-octyloxy, 2-ethylhexyloxy and SCH.sub.3.
[0034] Suitable halogen radicals or halogen substituents in the
context of the present application are fluorine, chlorine, bromine
and iodine, preferably fluorine, chlorine and bromine, more
preferably fluorine and chlorine, most preferably fluorine.
[0035] In the context of the present application, groups with donor
or acceptor action are understood to mean the following groups:
C.sub.1-C.sub.20-alkoxy, C.sub.6-C.sub.30-aryloxy,
C.sub.1-C.sub.20-alkylthio, C.sub.6-C.sub.30-arylthio,
SiR.sup.32R.sup.33R.sup.34, halogen radicals, halogenated
C.sub.1-C.sub.20-alkyl radicals, carbonyl (--CO(R.sup.32)),
carbonylthio (--C.dbd.O(SR.sup.32)), carbonyloxy
(--C.dbd.O(OR.sup.32)), oxycarbonyl (--OC.dbd.O(R.sup.32)),
thiocarbonyl (--SC.dbd.O(R.sup.32)), amino (--NR.sup.32R.sup.33),
OH, pseudohalogen radicals, amido (--C.dbd.O(NR.sup.32R.sup.33)),
--NR.sup.32C.dbd.O(R.sup.33), phosphonate (--P(O)(OR.sup.32).sub.2,
phosphate (--OP(O)(OR.sup.32).sub.2), phosphine
(--PR.sup.32R.sup.33), phosphine oxide (--P(O)R.sup.32.sub.2),
sulfate (--OS(O).sub.2OR.sup.32), sulfoxide (--S(O)R.sup.32),
sulfonate (--S(O).sub.2OR.sup.32), sulfonyl (--S(O).sub.2R.sup.32),
sulfonamide (--S(O).sub.2NR.sup.32R.sup.33), NO.sub.2, boronic
esters (--OB(OR.sup.32).sub.2), imino (--C.dbd.NR.sup.32R.sup.33)),
borane radicals, stannate radicals, hydrazine radicals, hydrazone
radicals, oxime radicals, nitroso groups, diazo groups, vinyl
groups, sulfoximines, alanes, germanes, boroxines and
borazines.
[0036] Preferred substituents with donor or acceptor action are
selected from the group consisting of: C.sub.1- to C.sub.20-alkoxy,
preferably C.sub.1-C.sub.6-alkoxy, more preferably ethoxy or
methoxy; C.sub.6-C.sub.30-aryloxy, preferably
C.sub.6-C.sub.10-aryloxy, more preferably phenyloxy;
SiR.sup.32R.sup.33R.sup.34, where R.sup.32, R.sup.33 and R.sup.34
are preferably each independently substituted or unsubstituted
alkyl or substituted or unsubstituted phenyl, suitable substituents
having been specified above; halogen radicals, preferably F, Cl,
Br, more preferably F or Cl, most preferably F, halogenated
C.sub.1-C.sub.20-alkyl radicals, preferably halogenated
C.sub.1-C.sub.6-alkyl radicals, most preferably fluorinated
C.sub.1-C.sub.6-alkyl radicals, e.g. CF.sub.3, CH.sub.2F, CHF.sub.2
or C.sub.2F.sub.5; amino, preferably dimethylamino, diethylamino or
diphenylamino; OH, pseudohalogen radicals, preferably CN, SCN or
OCN, more preferably CN, --C(O)OC.sub.1-C.sub.4-alkyl, preferably
--C(O)OMe, P(O)R.sub.2, preferably P(O)Ph.sub.2, and
SO.sub.2R.sub.2, preferably SO.sub.2Ph.
[0037] Very particularly preferred substituents with donor or
acceptor action are selected from the group consisting of methoxy,
phenyloxy, halogenated C.sub.1-C.sub.4-alkyl, preferably CF.sub.3,
CH.sub.2F, CHF.sub.2, C.sub.2F.sub.5, halogen, preferably F, CN,
SiR.sup.32R.sup.33R.sup.34, where suitable R.sup.32, R.sup.33 and
R.sup.34 radicals are specified below, diphenylamino, or
--C(O)OC.sub.1-C.sub.4-alkyl.
[0038] The aforementioned groups with donor or acceptor action are
not intended to rule out the possibility that further radicals and
groups among those specified above may also have donor or acceptor
action. For example, the aforementioned heteroaryl radicals are
likewise groups with donor or acceptor action, and the
C.sub.1-C.sub.20-alkyl radicals are groups with donor action.
[0039] The R.sup.32, R.sup.33 and R.sup.34 radicals mentioned in
the aforementioned groups with donor or acceptor action are each
independently:
[0040] Hydrogen, substituted or unsubstituted
C.sub.1-C.sub.20-alkyl or substituted or unsubstituted
C.sub.6-C.sub.30-aryl or substituted or unsubstituted heteroaryl
having 5 to 30 ring atoms, suitable and preferred alkyl and aryl
radicals having been specified above. More preferably, the
R.sup.32, R.sup.33 and R.sup.34 radicals are C.sub.1-C.sub.6-alkyl,
e.g. methyl, ethyl, i-propyl or tert-butyl, or phenyl or pyridyl,
most preferably methyl or phenyl.
Structures of the Organic Electronic Devices
[0041] Suitable structures of the organic electronic devices are
known to those skilled in the art. Preferred organic electronic
devices are selected from organic light-emitting diodes (OLED),
light-emitting electrochemical cells (LEEC), organic photovoltaic
cells (OPV) and organic field-effect transistors (OFET). More
preferred organic electronic devices are OLEDs.
[0042] The organic light-emitting diode (OLED) is usually a
light-emitting diode (LED) in which the emissive electroluminescent
layer is a film of organic compound which emits light in response
to an electric current. This layer of organic semiconductor is
usually situated between two electrodes. Generally, at least one of
these electrodes is transparent. The metal-carbene complex
comprising one, two or three, preferably three, bidentate ligands
of formula (I) and/or (I') may be present in any desired layer,
preferably in the emissive electroluminescent layer (light-emitting
layer), of the OLED as emitter material.
[0043] The light-emitting electrochemical cell (LEEC) is usually a
solid-state device that generates light from an electric current
(electroluminescence). LEEC's are usually composed of two metal
electrodes connected by (e.g. sandwiching) an organic semiconductor
containing mobile ions. Aside from the mobile ions, their structure
is very similar to that of an organic light-emitting diode (OLED).
The metal-carbene complex comprising one, two or three, preferably
three, bidentate ligands of formula (I) and/or (I') may be present
in any desired layer as emitter material.
[0044] The organic field-effect transistor (OFET) generally
includes a semiconductor layer formed from an organic layer with
hole transport capacity and/or electron transport capacity; a gate
electrode formed from a conductive layer; and an insulation layer
introduced between the semiconductor layer and the conductive
layer. A source electrode and a drain electrode are mounted on this
arrangement in order thus to produce the transistor element. In
addition, further layers known to those skilled in the art may be
present in the organic transistor. The metal-carbene complex
comprising one, two or three, preferably three, bidentate ligands
of formula (I) and/or (I') may be present in any desired layer.
[0045] The organic photovoltaic cell (OPV) (photoelectric
conversion element) generally comprises an organic layer present
between two plate-type electrodes arranged in parallel. The organic
layer may be configured on a comb-type electrode. There is no
particular restriction regarding the site of the organic layer and
there is no particular restriction regarding the material of the
electrodes. When, however, plate-type electrodes arranged in
parallel are used, at least one electrode is preferably formed from
a transparent electrode, for example an ITO electrode or a
fluorine-doped tin oxide electrode. The organic layer is usually
formed from two sublayers, i.e. a layer with p-type semiconductor
character or hole transport capacity, and a layer formed with
n-type semiconductor character or electron transport capacity. In
addition, it is possible for further layers known to those skilled
in the art to be present in the organic solar cell. The
metal-carbene complex comprising one, two or three, preferably
three, bidentate ligands of formula (I) and/or (I') may be present
in any desired layer, of the OPV, preferably as absorption dye.
[0046] The organic electronic device is most preferably an OLED or
OPV, wherein the metal-carbene complex comprising one, two or three
bidentate ligands of formula (I) and/or (I') is employed as emitter
material in OLEDs or LEECs, preferably OLEDs, or absorption dye in
OPVs. The organis electronic device is most preferably an OLED,
wherein the metal-carbene complex comprising one, two or three
bidentate ligands of formula (I) and/or (I') is employed as emitter
material.
[0047] The present invention therefore preferably relates to an
organic electronic device which is an OLED, wherein the OLED
comprises
(a) an anode, (b) a cathode, (c) a light-emitting layer between the
anode and the cathode, wherein the metal-carbene complex comprising
one, two or three bidentate ligands of formula (I) and/or (I') is
present in the light-emitting layer of the OLED.
[0048] The structure of the inventive OLED will be described in
detail below.
Metal-Carbene Complex Comprising One, Two or Three Bidentate
Ligands of Formula (I) and/or (I')
[0049] The metal in the metal-carbene complex comprising one, two
or three bidentate ligands of formula (I) and/or (I') is Ir or Pt,
preferably Ir(III) or Pt(II), more preferably, the metal in the
metal-carbene complex comprising one, two or three bidentate
ligands of formula (I) and/or (I') is Ir(III).
[0050] The radicals, groups and symbols in the bidentate ligands of
formula (I) and/or (I') of the metal-carbene complex preferably
have--independently of each other--the following meanings:
R.sup.1 has preferably the following meaning:
##STR00003##
wherein
R.sup.6
[0051] is hydrogen; deuterium; a linear or branched alkyl radical
having a total of from 1 to 10 carbon atoms, preferably methyl,
ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl or
iso-butyl; a linear or branched alkyl radical having a total of
from 1 to 10 carbon atoms bearing at least one fluoro radical,
preferably a linear or branched perfluoroalkyl radical, more
preferably CF.sub.3 and CF.sub.2CF.sub.3; a substituted or
unsubstituted cycloalkyl radical, having a total of from 3 to 30
carbon atoms, preferably cyclopentyl or cyclohexyl; a substituted
or unsubstituted heterocyclo alkyl radical, interrupted by at least
one heteroatom, selected from O, S and N, having a total of from 3
to 30 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical, having from 6 to 30 carbon atoms; a
substituted or unsubstituted heteroaryl radical, having a total of
from 5 to 30 carbon atoms and/or heteroatoms, selected from O, S
and N, preferably, the aryl radical or heteroaryl radical are
selected from the group consisting of an unsubstituted aryl
radical, having from 6 to 18 carbon atoms, a monosubstituted aryl
radical having from 6 to 18 carbon atoms, a disubstituted aryl
radical having from 6 to 18 carbon atoms, an unsubstituted
heteroaryl radical, having a total of from 5 to 18 carbon atoms
and/or heteroatoms, a monosubstituted heteroaryl radical, having a
total of from 5 to 18 carbon atoms and/or heteroatoms, a
disubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms, more preferably, the aryl radical
or heteroaryl radical are selected from the group consisting of
phenyl, tolyl, xylyl, diisopropylphenyl, pyridyl, methylpyridyl,
pyrimidyl, pyazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl,
fluorenyl, dimethylfluorenyl, indolyl, methylindolyl, benzofuranyl
and benzothiophenyl; or SiR.sup.9R.sup.10R.sup.11, preferably
SiMe.sub.3, SiPh.sub.3, SiEt.sub.3 or SiPh.sub.2tBu; R.sup.9,
R.sup.10, R.sup.11 are each independently a linear or branched
alkyl radical, having from 1 to 6 carbon atoms, preferably methyl,
ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl or
iso-butyl; a substituted or unsubstituted aryl radical, having from
6 to 18 carbon atoms, preferably phenyl or tolyl; a substituted or
unsubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 18 carbon atoms,
preferably cyclopentyl or cyclohexyl; R.sup.7 and R.sup.8 are each
independently hydrogen, deuterium, a linear or branched alkyl
radical, having from 1 to 6 carbon atoms, preferably methyl, ethyl,
n-propyl, iso-propyl; a linear or branched alkyl radical having a
total of from 1 to 6 carbon atoms bearing at least one fluoro
radical, preferably a linear or branched perfluoroalkyl radical,
more preferably CF.sub.3 and CF.sub.2CF.sub.3; or halogen,
preferably F; m is 1, 2, 3, 4 or 5, preferably 1, 2 or 3, more
preferably 1 or 2; .about. is the bonding site to the ligand of
formula (I) or (I').
[0052] Examples for more preferred radicals R.sup.1 are:
##STR00004##
wherein
R.sup.6
[0053] is hydrogen, deuterium, methyl, ethyl, n-propyl, iso-propyl,
n-butyl, tert-butyl, iso-butyl, sec-butyl, phenyl, tolyl, xylyl,
pyridyl, methylpyridyl, pyrimidyl, pyazinyl, carbazolyl,
dibenzofuranyl, dibenzothiophenyl, fluorenyl, dimethylfluorenyl,
indolyl, methylindolyl, benzofuranyl, benzothiophenyl; cyclopentyl,
cyclohexyl; CF.sub.3, CF.sub.2CF.sub.3; SiMe.sub.3, SiEt.sub.3,
SiPh.sub.3 or SiPh.sub.2tBu; and R.sup.7 and R.sup.8 are hydrogen,
deuterium, methyl, ethyl or n-propyl, preferably hydrogen or
methyl, ethyl, or fluoro; more preferably, R.sup.7 and Ware at the
same time hydrogen or R.sup.7 and Ware at the same time methyl;
.about. is the bonding site to the ligand of formula (I) or (I').
A.sup.1, A.sup.1', A.sup.2, A.sup.2', A.sup.3, A.sup.3', A.sup.4
and A.sup.4' have preferably the following meanings: A.sup.1 is
CR.sup.2; A.sup.2 is CR.sup.3; A.sup.3 is CR.sup.4; A.sup.4 is
CR.sup.5; A.sup.1' is CR.sup.2'; A.sup.2' is CR.sup.3'; A.sup.3' is
CR.sup.4'; A.sup.4' is CR.sup.5';
[0054] Preferably, at least A.sup.1, A.sup.1', A.sup.4 and A.sup.4'
are each CH, more preferably, A.sup.1, A.sup.1', A2, A.sup.2',
A.sup.3, A.sup.3', A.sup.4 and A.sup.4' are each CH.
[0055] R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3',
R.sup.4' and R.sup.5' have preferably the following meanings:
R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3', R.sup.4'
and R.sup.5' are each independently hydrogen; deuterium; a linear
or branched, substituted or unsubstituted alkyl radical having 1 to
20 carbon atoms, optionally interrupted by at least one heteroatom,
selected from O, S and N; a substituted or unsubstituted cycloalkyl
radical, having a total of from 3 to 10 carbon atoms; a substituted
or unsubstituted heterocyclo alkyl radical, interrupted by at least
one heteroatom, selected from O, S and N, and having a total of
from 3 to 10 carbon atoms and/or heteroatoms; a group with donor or
acceptor action, selected from halogen radicals, preferably F or
Cl, more preferably F, CF.sub.3, CN, SiPh.sub.3 and SiMe.sub.3; a
substituted or unsubstituted aryl radical, having from 6 to 30
carbon atoms; preferably hydrogen; deuterium; a linear or branched
alkyl radical, having from 1 to 4 carbon atoms; a group with donor
or acceptor action, selected from the group consisting of F,
CF.sub.3, CN, SiPh.sub.3 and SiMe.sub.3; or a unsubstituted,
monosubstituted or distubstituted aryl radical having 6 to 20
carbon atoms; more preferably hydrogen, methyl, ethyl, n-propyl,
iso-propyl, n-butyl, sec-butyl, tert-butyl or iso-butyl; or a
unsubstituted, monosubstituted or distubstituted aryl radical
having 6 to 20 carbon atoms.
[0056] According to the invention, the carbene ligands (I) and
(I')
##STR00005##
in the metal-carbene complex are monoanionic bidentate ligands.
[0057] Particularly preferably, the present invention concerns an
organic electronic device, preferably an OLED, comprising at least
one metal-carbene complex, wherein the metal is Ir, comprising
three bidentate ligands of formula (I) and/or (I')
##STR00006##
wherein
R.sup.1
[0058] is a linear or branched alkyl radical having 1 to 20 carbon
atoms, which is linked to the diazabenzimidazole carbene unit via a
sp.sup.3 hybridized carbon atom, optionally interrupted by at least
one heteroatom, selected from O, S and N, optionally substituted
with at least one of the following groups: a group with donor or
acceptor action; deuterium; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 30 carbon atoms; a
substituted or unsubstituted heterocyclo alkyl radical, interrupted
by at least one heteroatom, selected from O, S and N, and having a
total of from 3 to 30 carbon atoms and/or heteroatoms; a
substituted or unsubstituted aryl radical, having a total of from 6
to 30 carbon atoms; or a substituted or an unsubstituted heteroaryl
radical, having a total of from 5 to 30 carbon atoms and/or
heteroatoms, selected from O, S and N; a cycloalkyl radical having
a total of from 4 to 30 carbon atoms, optionally substituted by a
linear or branched, substituted or unsubstituted alkyl radical,
optionally interrupted by at least one heteroatom, selected from O,
S and N, and/or at least one of the groups mentioned above
concerning the linear or branched alkyl radical; or a heterocyclo
alkyl radical, which is linked to the diazabenzimidazole carbene
unit via a sp.sup.3 hybridized carbon atom, interrupted by at least
one heteroatom, selected from O, S and N, and having a total of
from 3 to 30 carbon atoms and/or heteroatoms, optionally
substituted by a linear or branched, substituted or unsubstituted
alkyl radical, optionally interrupted by at least one heteroatom,
selected from O, S and N, and/or at least one of the groups
mentioned above concerning the linear or branched alkyl radical;
and .about. is the bonding site to the metal.
[0059] Preferred radicals R.sup.1 are mentioned above.
[0060] More preferably, the metal-carbene complex comprising one,
two or three bidentate ligands of formula (I) and/or (I') has one
of the following formulae (II), (II') or (II''):
##STR00007##
wherein
R.sup.1
[0061] is a linear or branched alkyl radical having 1 to 20 carbon
atoms, which is linked to the diazabenzimidazole carbene unit via a
spa hybridized carbon atom, optionally interrupted by at least one
heteroatom, selected from O, S and N, optionally substituted with
at least one of the following groups: a group with donor or
acceptor action; deuterium; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 30 carbon atoms; a
substituted or unsubstituted heterocyclo alkyl radical, interrupted
by at least one heteroatom, selected from O, S and N, and having a
total of from 3 to 30 carbon atoms and/or heteroatoms; a
substituted or unsubstituted aryl radical, having a total of from 6
to 30 carbon atoms; or a substituted or an unsubstituted heteroaryl
radical, having a total of from 5 to 30 carbon atoms and/or
heteroatoms, selected from O, S and N; a cycloalkyl radical having
a total of from 4 to 30 carbon atoms, optionally substituted by a
linear or branched, substituted or unsubstituted alkyl radical,
optionally interrupted by at least one heteroatom, selected from O,
S and N, and/or at least one of the groups mentioned above
concerning the linear or branched alkyl radical; or a heterocyclo
alkyl radical, which is linked to the diazabenzimidazole carbene
unit via a spa hybridized carbon atom, interrupted by at least one
heteroatom, selected from O, S and N, and having a total of from 3
to 30 carbon atoms and/or heteroatoms, optionally substituted by a
linear or branched, substituted or unsubstituted alkyl radical,
optionally interrupted by at least one heteroatom, selected from O,
S and N, and/or at least one of the groups mentioned above
concerning the linear or branched alkyl radical; A.sup.1 is
CR.sup.2 or N; preferably CR.sup.2; A.sup.2 is CR.sup.3 or N;
preferably CR.sup.3; A.sup.3 is CR.sup.4 or N; preferably CR.sup.4;
A.sup.4 is CR.sup.5 or N; preferably CR.sup.5; A.sup.1' is
CR.sup.2' or N; preferably CR.sup.2'; A.sup.2' is CR.sup.3' or N;
preferably CR.sup.3'; A.sup.3' is CR.sup.4' or N; preferably
CR.sup.4'; A.sup.4' is CR.sup.5' or N; preferably CR.sup.5';
R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3', R.sup.4'
and R.sup.5' are each independently hydrogen; deuterium; a linear
or branched, substituted or unsubstituted alkyl radical having 1 to
20 carbon atoms, optionally interrupted by at least one heteroatom,
selected from O, S and N; a substituted or unsubstituted cycloalkyl
radical having a total of from 3 to 30 carbon atom; a substituted
or unsubstituted heterocyclo alkyl radical, interrupted by at least
one heteroatom selected from O, S and N and having a total of from
3 to 30 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical, having a total of from 6 to 30 carbon
atoms; a substituted or unsubstituted heteroaryl radical, having a
total of from 5 to 30 carbon atoms and/or heteroatoms, selected
from O, S and N; or a group with donor or acceptor action;
preferably, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.2', R.sup.3',
R.sup.4' and R.sup.5' are each independently hydrogen, deuterium, a
linear or branched, substituted or unsubstituted alkyl radical,
having 1 to 20 carbon atoms; an unsubstituted aryl radical, having
from 6 to 18 carbon atoms, a monosubstituted aryl radical having
from 6 to 18 carbon atoms, a disubstituted aryl radical having from
6 to 18 carbon atoms; an unsubstituted heteroaryl radical, having a
total of from 5 to 18 carbon atoms and/or heteroatoms, a
monosubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms, a disubstituted heteroaryl
radical, having a total of from 5 to 18 carbon atoms and/or
heteroatoms; more preferably, the aryl radical or heteroaryl
radical are selected from the group consisting of phenyl, tolyl,
xylyl, diisopropylphenyl, pyridyl, methylpyridyl, pyrimidyl,
pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl,
fluorenyl, dimethylfluorenyl, indolyl, methylindolyl, benzofuranyl
and benzothiophenyl; a group with donor or acceptor action,
selected from halogen radicals, preferably F or Cl, more preferably
F; CF.sub.3, CN; or SiR.sup.9R.sup.10R.sup.11, preferably
SiMe.sub.3, SiPh.sub.3, SiEt.sub.3 or SiPh.sub.2tBu; R.sup.9,
R.sup.10, R.sup.11 are each independently a linear or branched
alkyl radical, having from 1 to 6 carbon atoms, preferably methyl,
ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl or
iso-butyl; a substituted or unsubstituted aryl radical, having from
6 to 18 carbon atoms, preferably phenyl or tolyl; a substituted or
unsubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 18 carbon atoms,
preferably cyclopentyl or cyclohexyl; or R.sup.2 and R.sup.3,
R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.2' and
R.sup.3', R.sup.3' and R.sup.4' or R.sup.4' and R.sup.5' may form,
independently of each other, together with the carbon atoms to
which they are bonded, a saturated or unsaturated or aromatic,
optionally substituted ring, which is optionally interrupted by at
least one heteroatom, selected from O, S and N, has a total of from
5 to 18 carbon atoms and/or heteroatoms, and may optionally be
fused to at least one further optionally substituted saturated or
unsaturated or aromatic ring, optionally interrupted by at least
one heteroatom, selected from 0, S and N, and having a total of
from 5 to 18 carbon atoms and/or heteroatoms; M is Ir or Pt,
preferably Ir(III) or Pt(II), more preferably Ir(III); n is in the
case that M is Ir 1, 2 or 3, preferably 3; in the case that M is Pt
1 or 2, preferably 1; L is a monoanionic bidentate ligand, o is in
the case that M is Ir 0, 1 or 2, where, when o=2, the L ligands may
be the same or different, preferably 0; in the case that M is Pt 0
or 1, preferably 1; n' is in the case that M is Ir 1 or 2; in the
case that M is Pt 1; n'' is in the case that M is Ir 1 or 2; in the
case that M is Pt 1; wherein in the case that M is Ir, the sum of
n'+n'' is 2 or 3, preferably 3; in the case that M is Pt, the sum
of n'+n'' is 2; o' is in the case that M is Ir 0 or 1, preferably
0; in the case that M is Pt 0; wherein in the case that M is Ir the
sum of n+o in formulae (II) and (II') and the sum of n'+n''+o' in
formula (II'') is 3, with the proviso that n in formula (II) and
(II') is at least 1 and n', as well as n'' in formula (II'') are at
least 1; and in the case that M is Pt the sum of n+o in formulae
(II) and (II') and the sum of n'+n''+o' in formula (II'') is 2,
with the proviso that n in formula (II) and (II') is at least 1 and
n', as well as n'' in formula (II'') are both 1.
[0062] The carbene ligands in the Ir metal-carbene complexes of
formulae (II), (II') and (II'') are monoanionic bidentate
ligands
[0063] The carbene ligands in the metal-carbene complexes of
formulae (II), (II') and (II'') correspond to the carbene ligands
of formulae (I) and (I') mentioned above.
[0064] The Ir metal-carbene complexes of formulae (II), (II') and
(II'') are cyclometallation isomers.
[0065] Preferred definitions mentioned concerning the radicals and
groups R.sup.1, A.sup.1, A.sup.2, A.sup.3, A.sup.4, A.sup.1',
A.sup.2', A.sup.3' and A.sup.4' in the carbene ligands of formulae
(I) and (I') mentioned above are also preferred definitions
concerning said radicals and groups in the metal-carbene complexes
of formulae (II), (II') and (II''). The .about. in the definition
of R.sup.1 is in the case of the metal-carbene complexes of
formulae (II), (II') and (II'') the bonding site to the carbene
ligand in the metal-carbene complexes of formulae (II), (II') and
(II'').
[0066] A bidentate ligand is understood to mean a ligand
coordinated at two sites to the transition metal atom M.
[0067] Suitable monoanionic bidentate ligands L are preferably
selected from the group of ligands (A), (B) and (C). Ligands (A),
(B) and (C) are mentioned below:
[0068] Ligands of the formula (A):
##STR00008##
in which R.sup.51 is in each case independently a linear or
branched alkyl radical having 1 to 6 carbons atoms, preferably
methyl, ethyl, isopropyl or tert-butyl; a substituted or
unsubstituted aryl radical having 6 to 18 carbon atoms, preferably
an unsubstituted phenyl or 2,6-dialkylphenyl; a substituted or
unsubstituted heteroaryl radical having a total of 5 to 18 carbon
atoms and/or heteroatoms, R.sup.52 is hydrogen; a linear or
branched alkyl radical having 1 to 6 carbon atoms; a substituted or
unsubstituted aryl radical having 6 to 18 carbon atoms; preferably
hydrogen or 2,6-dimethylphenyl; where the ligand of the formula (A)
is preferably acetylacetonato.
[0069] Ligands of the formula (B):
##STR00009##
where A.sup.9' is CR.sup.12' or N; A.sup.10' is CR.sup.13' or N;
R.sup.11' is a linear or branched, substituted or unsubstituted
alkyl radical having 1 to 20 carbon atoms, optionally interrupted
by at least one heteroatom, selected from O, S and N; a substituted
or unsubstituted cycloalkyl radical having 3 to 18 carbon atoms; a
substituted or unsubstituted heterocycloalkyl radical interrupted
by at least one heteroatom, selected from O, S and N, and having 3
to 18 carbon atoms and/or heteroatoms; a substituted or
unsubstituted aryl radical having 6 to 30 carbon atoms, a
substituted or unsubstituted heteroaryl radical interrupted by at
least one heteroatom, selected from O, S and N and having a total
of 5 to 30 carbon atoms and/or heteroatoms; R.sup.12', R.sup.13'
are each independently hydrogen; deuterium; a linear or branched,
substituted or unsubstituted alkyl radical having 1 to 20 carbon
atoms, optionally interrupted by at least one heteroatom, selected
from O, S and N; a substituted or unsubstituted cycloalkyl radical
having 3 to 18 carbon atoms; a substituted or unsubstituted
heterocycloalkyl radical interrupted by at least one heteroatom,
selected from O, S and N, and having 3 to 18 carbon atoms and/or
heteroatoms; a substituted or unsubstituted aryl radical having 6
to 30 carbon atoms; a substituted or unsubstituted heteroaryl
radical interrupted by at least one heteroatom, selected from O, S
and N and having a total of 5 to 30 carbon atoms and/or
heteroatoms; or a group with donor or acceptor action; if A.sup.9'
is CR.sup.12' and A.sup.10' is CR.sup.13', CR.sup.12' and
CR.sup.13' together may form, a saturated or unsaturated or
aromatic, optionally substituted ring, which is optionally
interrupted by at least one heteroatom, selected from O, S and N,
has a total of from 5 to 18 carbon atoms and/or heteroatoms, and
may optionally be fused to at least one further optionally
substituted saturated or unsaturated or aromatic ring, optionally
interrupted by at least one heteroatom, selected from O, S and N,
and having a total of from 5 to 18 carbon atoms and/or heteroatoms;
A.sup.5' is CR.sup.14' or N; preferably CR.sup.14'; A.sup.6' is
CR.sup.15' or N; preferably CR.sup.15'; A.sup.7' is CR.sup.16' or
N; preferably CR.sup.16'; A.sup.8' is CR.sup.17' or N; preferably
CR.sup.17'; R.sup.14', R.sup.15', R.sup.16', R.sup.17' are each
independently hydrogen; deuterium; a linear or branched,
substituted or unsubstituted alkyl radical having 1 to 20 carbon
atoms, optionally interrupted by at least one heteroatom, selected
from O, S and N; a substituted or unsubstituted cycloalkyl radical
having 3 to 18 carbon atoms; a substituted or unsubstituted
heterocycloalkyl radical interrupted by at least one heteroatom,
selected from O, S and N, and having 3 to 18 carbon atoms and/or
heteroatoms; a substituted or unsubstituted aryl radical having 6
to 30 carbon atoms; a substituted or unsubstituted heteroaryl
radical interrupted by at least one heteroatom, selected from O, S
and N and having a total of 5 to 30 carbon atoms and/or
heteroatoms; or a group with donor or acceptor action; or R.sup.14'
and R.sup.15', R.sup.15' and R.sup.16' or R.sup.16' and R.sup.17'
may form, together with the carbon atoms to which they are bonded,
a saturated or unsaturated or aromatic, optionally substituted
ring, which is optionally interrupted by at least one heteroatom,
selected from O, S and N, has a total of from 5 to 18 carbon atoms
and/or heteroatoms, and may optionally be fused to at least one
further optionally substituted saturated or unsaturated or aromatic
ring, optionally interrupted by at least one heteroatom, selected
from O, S and N, and having a total of from 5 to 18 carbon atoms
and/or heteroatoms; or if A.sup.9' is CR.sup.12', R.sup.12' and
R.sup.17' together may form a saturated or unsaturated, linear or
branched bridge optionally comprising heteroatoms, selected from O,
S and N, to which is optionally fused a substituted or
unsubstituted, five- to eight-membered ring comprising carbon atoms
and/or heteroatoms, and which are optionally substituted with
aromatic units, heteroaromatic units or groups with donor or
acceptor action; q' is 0 or 1.
[0070] More preferred ligands of formula (B) are:
##STR00010##
[0071] A most preferred ligand of formula (B) is:
##STR00011##
[0072] Ligands of formula (C):
##STR00012##
in which the symbols are each defined as follows: D are each
independently CR.sup.34''' or N;
W is C or N;
[0073] E are each independently CR.sup.35''', N, NR.sup.36''' or
O;
I is 1 or 2;
[0074] R.sup.34''', R.sup.35''', R.sup.36''' are [0075] each
independently hydrogen; alkyl; aryl or heteroaryl; [0076] or [0077]
in each case two R.sup.34''', R.sup.35''' or R.sup.36''' radicals
together form a fused ring which may optionally comprise at least
one heteroatom; [0078] or [0079] R.sup.34''', R.sup.35''',
R.sup.36''' or R.sup.37''' is a radical having donor or acceptor
action; [0080] where the dotted line means an optional bridge
between one of the D groups and one of the E groups; where the
bridge may be defined as follows: [0081] alkylene, arylene,
heteroarylene, alkynylene, alkenylene, NR.sup.38''', O, S,
SiR.sup.41'''R.sup.42''', CO, CO--O, O--CO and
(CR.sup.43'''R.sup.44''').sub.v, where one or more nonadjacent
(CR.sup.43'''R.sup.44''') groups may be replaced by NR.sup.38''',
O, S, SiR.sup.41'''R.sup.42''', CO, CO--O or O--CO, where v is from
2 to 10; and R.sup.38''', R.sup.41''', R.sup.42''', R.sup.43''',
R.sup.44''' [0082] are each H, alkyl, aryl or heteroaryl.
[0083] Preferred ligands L in the Ir(III) complexes of formulae
(II), (II') and (II'') are ligands (B). Therefore, in a preferred
embodiment, the metal-carbene complexes of formulae (II), (II') and
(II''), wherein M is Ir(III), exclusively have carbene ligands.
[0084] Preferably, o in the metal-carbene complexes of the formulae
(II) and (II'), wherein M is Ir(III), is 0 and o' in the
metal-carbene complexes of the formula (II'') is 0. In this case, n
in formulae (II) and (II') is preferably 3 and n' and n'' in
formula (II'') are 1 or 2, wherein the sum of n' and n'' is 3.
[0085] Preferred ligands L in the Pt(II) complexes of formulae
(II), (II') and (II'') are ligands (A).
[0086] Preferably, o in the metal-carbene complexes of the formulae
(II) and (II'), wherein M is Pt(II), is 1 and o' in the
metal-carbene complexes of the formula (II'') is 1. In this case, n
in formulae (II) and (II') is preferably 1 and one of n' and n'' in
formula (II'') is 1 and the other one is 0, wherein the sum of n'
and n'' is 1.
[0087] The n diazabenzimidazole carbene ligands may each be the
same or different in the metal-carbene complexes of the general
formulae (II), (II') and (II''). They are preferably the same. The
metal-carbene complex of the general formula (II'') preferably
comprises three identical carbene ligands--in the case that M is
Ir(III)--or two identical carbene ligands--in the case that M is
Pt(II)--wherein the bonding situation in one of the carbene ligands
is different from the bonding situation in the other one (in the
case that M is Pt(II)) or two (in the case that M is Ir(III))
further carbene ligands as shown in formula (II'').
[0088] Particularly preferably, the metal-carbene complex
comprising one, two or three bidentate ligands of formula (I)
and/or (I') has one of the following formulae (IIa), (II'a),
(II''a) or (II''a'):
##STR00013##
wherein
R.sup.1
[0089] is a linear or branched alkyl radical having 1 to 20 carbon
atoms, which is linked to the diazabenzimidazole carbene unit via a
spa hybridized carbon atom, optionally interrupted by at least one
heteroatom, selected from O, S and N, optionally substituted with
at least one of the following groups: a group with donor or
acceptor action; deuterium; a substituted or unsubstituted
cycloalkyl radical having a total of from 3 to 30 carbon atoms; a
substituted or unsubstituted heterocyclo alkyl radical, interrupted
by at least one heteroatom, selected from O, S and N, and having a
total of from 3 to 30 carbon atoms and/or heteroatoms; a
substituted or unsubstituted aryl radical, having a total of from 6
to 30 carbon atoms; or a substituted or an unsubstituted heteroaryl
radical, having a total of from 5 to 30 carbon atoms and/or
heteroatoms, selected from O, S and N; a cycloalkyl radical having
a total of from 4 to 30 carbon atoms, optionally substituted by a
linear or branched, substituted or unsubstituted alkyl radical,
optionally interrupted by at least one heteroatom, selected from O,
S and N, and/or at least one of the groups mentioned above
concerning the linear or branched alkyl radical; or a heterocyclo
alkyl radical, which is linked to the diazabenzimidazole carbene
unit via a spa hybridized carbon atom, interrupted by at least one
heteroatom, selected from O, S and N, and having a total of from 3
to 30 carbon atoms and/or heteroatoms, optionally substituted by a
linear or branched, substituted or unsubstituted alkyl radical,
optionally interrupted by at least one heteroatom, selected from O,
S and N, and/or at least one of the groups mentioned above
concerning the linear or branched alkyl radical.
[0090] Preferred radicals R.sup.1 are mentioned above.
[0091] There exist cyclometallation isomers of the complexes
mentioned below which are covered by the disclosure of the present
invention, even if only one cyclometallation isomer is shown.
[0092] Examples for carbene complexes of the general formulae (II),
(II') and (II'') are the following Ir- and Pt-carbene complexes,
wherein the following Ir carbene complexes are preferred:
##STR00014##
wherein
R.sup.6
[0093] is hydrogen; deuterium; a linear or branched alkyl radical
having a total of from 1 to 10 carbon atoms, preferably methyl,
ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl or iso-butyl; a
linear or branched alkyl radical having a total of from 1 to 10
carbon atoms bearing at least one fluoro radical, preferably a
linear or branched perfluoroalkyl radical, more preferably CF.sub.3
and CF.sub.2CF.sub.3; a substituted or unsubstituted cycloalkyl
radical, having a total of from 3 to 30 carbon atoms, preferably
cyclopentyl or cyclohexyl; a substituted or unsubstituted
heterocyclo alkyl radical, interrupted by at least one heteroatom,
selected from O, S and N, having a total of from 3 to 30 carbon
atoms and/or heteroatoms; a substituted or unsubstituted aryl
radical, having from 6 to 18 carbon atoms; a substituted or
unsubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms, selected from O, S and N,
preferably, the aryl radical or heteroaryl radical are selected
from the group consisting of an unsubstituted aryl radical, having
from 6 to 18 carbon atoms, a monosubstituted aryl radical having
from 6 to 18 carbon atoms, a disubstituted aryl radical having from
6 to 18 carbon atoms, an unsubstituted heteroaryl radical, having a
total of from 5 to 18 carbon atoms and/or heteroatoms, a
monosubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms, a disubstituted heteroaryl
radical, having a total of from 5 to 18 carbon atoms and/or
heteroatoms, more preferably, the aryl radical or heteroaryl
radical are selected from the group consisting of phenyl, tolyl,
xylyl, pyridyl, methylpyridyl, pyrimidyl, pyazinyl, carbazolyl,
dibenzofuranyl, di benzothiophenyl, fluorenyl, dimethylfluorenyl,
indolyl, methylindolyl, benzofuranyl and benzothiophenyl; or
SiR.sup.9R.sup.10R.sup.11, preferably SiMe.sub.3, SiPh.sub.3,
SiEt.sub.3 or SiPh.sub.2tBu; R.sup.9, R.sup.10, R.sup.11 are each
independently a linear or branched alkyl radical, having from 1 to
6 carbon atoms, preferably methyl, ethyl, n-propyl, iso-propyl,
n-butyl, tert-butyl or iso-butyl; a substituted or unsubstituted
aryl radical, having from 6 to 18 carbon atoms, preferably phenyl
or tolyl; a substituted or unsubstituted heteroaryl radical, having
a total of from 5 to 18 carbon atoms and/or heteroatoms; a
substituted or unsubstituted cycloalkyl radical having a total of
from 3 to 18 carbon atoms, preferably cyclopentyl or cyclohexyl;
R.sup.7 and R.sup.8 are each independently hydrogen, deuterium, a
linear or branched alkyl radical, having from 1 to 6 carbon atoms,
preferably methyl, ethyl, n-propyl, iso-propyl; a linear or
branched alkyl radical having a total of from 1 to 6 carbon atoms
bearing at least one fluoro radical, preferably a linear or
branched perfluoroalkyl radical, more preferably CF.sub.3 and
CF.sub.2CF.sub.3; or halogen, preferably F; m is 1, 2, 3, 4 or 5,
preferably 1, 2 or 3 more preferably 1 or 2;
R.sup.51
[0094] is in each case independently a linear or branched alkyl
radical having 1 to 6 carbons atoms, preferably methyl, ethyl,
isopropyl or tert-butyl; a substituted or unsubstituted aryl
radical having 6 to 18 carbon atoms, preferably an unsubstituted
phenyl or 2,6-dialkylphenyl or 2,4,6-trialkylphenyl; a substituted
or unsubstituted heteroaryl radical having a total of 5 to 18
carbon atoms and/or heteroatoms; most preferably, R.sup.51 is
methyl, phenyl, 2,6-xylyl, 2,4,6-mesityl or
2,4,6-triisopropylphenyl; R.sup.52 is hydrogen; a linear or
branched alkyl radical having 1 to 6 carbon atoms; a substituted or
unsubstituted aryl radical having 6 to 18 carbon atoms; preferably
hydrogen.
[0095] Further examples of inventive Ir- and Pt-complexes are:
##STR00015##
wherein
R.sup.6
[0096] is hydrogen, deuterium, methyl, ethyl, n-propyl, iso-propyl,
n-butyl, tert-butyl, iso-butyl, phenyl, tolyl, xylyl, pyridyl,
methylpyridyl, pyrimidyl, pyazinyl, carbazolyl, dibenzofuranyl,
dibenzothiophenyl, fluorenyl, dimethylfluorenyl, indolyl,
methylindolyl, benzofuranyl, benzothiophenyl; cyclopentyl,
cyclohexyl; CF.sub.3, CF.sub.2CF.sub.3; SiMe.sub.3, SiPh.sub.3,
SiEt.sub.3 or SiPh.sub.2tBu; and R.sup.7 and R.sup.8 are hydrogen,
deuterium, methyl, ethyl or n-propyl, preferably hydrogen or
methyl, or fluoro; more preferably, R.sup.7 and R.sup.8 are at the
same time hydrogen or R.sup.7 and R.sup.8 are at the same time
methyl;
R.sup.51
[0097] is in each case independently methyl, tert-butyl, phenyl,
xylyl, 2,6-xylyl, 2,4,6-mesityl or 2,4,6-triisopropylphenyl; and
R.sup.52 is hydrogen.
[0098] Further examples for inventive Ir- and Pt-complexes are the
following complexes:
##STR00016##
wherein
TABLE-US-00001 R.sup.6 R.sup.7 R.sup.8 1 hydrogen hydrogen hydrogen
2 methyl hydrogen hydrogen 3 ethyl hydrogen hydrogen 4 n-propyl
hydrogen hydrogen 5 iso-propyl hydrogen hydrogen 6 n-butyl hydrogen
hydrogen 7 iso-butyl hydrogen hydrogen 8 tert-butyl hydrogen
hydrogen 9 methyl methyl hydrogen 10 ethyl methyl hydrogen 11
n-propyl methyl hydrogen 12 n-butyl methyl hydrogen 13 iso-butyl
methyl hydrogen 14 tert-butyl methyl hydrogen 15 Ethyl ethyl
hydrogen 16 n-propyl ethyl hydrogen 17 n-butyl ethyl hydrogen 18
iso-butyl ethyl hydrogen 19 tert-butyl ethyl hydrogen 20 iso-propyl
n-propyl hydrogen 21 n-butyl n-propyl hydrogen 22 iso-butyl
n-propyl hydrogen 23 tert-butyl n-propyl hydrogen 24 methyl methyl
methyl 25 ethyl methyl methyl 26 n-propyl methyl methyl 27
iso-propyl methyl methyl 28 n-butyl methyl methyl 29 iso-butyl
methyl methyl 30 tert-butyl methyl methyl 31 ethyl ethyl ethyl 32
n-propyl ethyl ethyl 33 iso-propyl ethyl ethyl 34 n-butyl ethyl
ethyl 35 iso-butyl ethyl ethyl 36 tert-butyl ethyl ethyl 37 ethyl
ethyl butyl 38 n-propyl ethyl propyl 39 iso-propyl ethyl propyl 40
n-butyl ethyl propyl 41 iso-butyl ethyl propyl 42 tert-butyl ethyl
propyl
[0099] As well as the following complexes:
##STR00017##
wherein
TABLE-US-00002 R.sup.6 R.sup.7 R.sup.8 51 phenyl hydrogen hydrogen
52 Tolyl hydrogen hydrogen 53 Xylyl hydrogen hydrogen 54 pyridyl
hydrogen hydrogen 55 methylpyridyl hydrogen hydrogen 56 pyrimidyl
hydrogen hydrogen 57 pyrazinyl hydrogen hydrogen 58 carbazolyl
hydrogen hydrogen 59 dibenzofuranyl hydrogen hydrogen 60
dimethylfluorenyl hydrogen hydrogen 61 methylindonyl hydrogen
hydrogen 62 --CH.sub.2-tolyl hydrogen hydrogen 63 --CH.sub.2-xylyl
hydrogen hydrogen 64 --CH.sub.2-pyridyl hydrogen hydrogen 65
--CH.sub.2-pyrazinyl hydrogen hydrogen 66
--CH.sub.2-methylpyridinyl hydrogen hydrogen 67
--CH.sub.2-dibenzofuranyl hydrogen hydrogen 68 --CMe.sub.2-methyl
hydrogen hydrogen 69 --CMe.sub.2-ethyl hydrogen hydrogen 70
--CMe.sub.2-propyl hydrogen hydrogen 71 --CMe.sub.2-iso-butyl
hydrogen hydrogen 72 cyclopentyl hydrogen hydrogen 73 cyclohexyl
hydrogen hydrogen 74 adamantyl hydrogen hydrogen 75
--CH.sub.2-adamantyl hydrogen hydrogen 76 CF.sub.3 hydrogen
hydrogen 77 CF.sub.2CF.sub.3 hydrogen hydrogen 78 SiMe.sub.3
hydrogen hydrogen 79 SiPh.sub.3 hydrogen hydrogen 80 phenyl methyl
methyl 81 tolyl methyl methyl 82 xylyl methyl methyl 83 pyridyl
methyl methyl 84 methylpyridyl methyl methyl 85 pyrimidyl methyl
methyl 86 pyrazinyl methyl methyl 87 carbazolyl methyl methyl 88
dibenzofuranyl methyl methyl 89 dimethylfluorenyl methyl methyl 90
methylindonyl methyl methyl 91 --CH.sub.2-tolyl methyl methyl 92
--CH.sub.2-xylyl methyl methyl 93 --CH.sub.2-pyridyl methyl methyl
94 --CH.sub.2-pyrazinyl methyl methyl 95 --CH.sub.2-methylpyridinyl
methyl methyl 96 --CH.sub.2-dibenzofuranyl methyl methyl 97
--CMe.sub.2-methyl methyl methyl 98 --CMe.sub.2-ethyl methyl methyl
99 --CMe.sub.2-propyl methyl methyl 100 --CMe.sub.2-iso-butyl
methyl methyl 101 cyclopentyl methyl methyl 102 cyclohexyl methyl
methyl 103 CF.sub.3 methyl methyl 104 CF.sub.2CF.sub.3 methyl
methyl 105 SiMe.sub.3 methyl methyl 106 SiPh.sub.3 methyl
methyl
[0100] As well as the following complexes:
##STR00018##
m is 0, 1, 2, 3, 4 or 5;
##STR00019##
m is 0, 1, 2, 3, 4 or 5; and
##STR00020##
wherein R.sup.6 is methyl, ethyl, n-propyl, iso-propyl, SiMe.sub.3,
SiEt.sub.3, SiPh.sub.3, cyclopentyl or cyclohexyl; R.sup.7, R.sup.8
are independently hydrogen, methyl, ethyl, n-propyl or iso-propyl;
R.sup.51 is in each case independently methyl, phenyl or
2,4,6-triisopropylphenyl; and R.sup.52 is hydrogen.
[0101] As well as the following complexes:
##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##
##STR00026## ##STR00027##
[0102] Further suitable complexes are the following complexes:
##STR00028## ##STR00029## ##STR00030##
wherein R.sup.6 is methyl, ethyl, n-propyl, iso-propyl, SiMe.sub.3,
SiEt.sub.3, SiPh.sub.3, cyclopentyl or cyclohexyl.
[0103] Further examples for inventive Ir- and Pt-complexes are:
##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035##
##STR00036## ##STR00037## ##STR00038## ##STR00039## ##STR00040##
##STR00041## ##STR00042##
[0104] Particularly preferred inventive metal-carbene complexes
comprising three bidentate ligands of formula (I) and/or (I') are
the following complexes:
##STR00043## ##STR00044## ##STR00045##
(isomeric mixture of cyclometallation isomers, shown are both
cyclometallation isomers)
[0105] There exist cyclometallation isomers of the complexes
mentioned above which are covered by the disclosure of the present
invention, even if only one cyclometallation isomer is shown.
[0106] The present invention also relates to a process for
preparing the inventive metal-carbene complexes comprising one, two
or three, preferably three in the case of Ir and preferably one in
the case of Pt, bidentate ligands of formula (I) and/or (I') by
contacting suitable compounds comprising Ir or Pt with the
appropriate ligands or ligand precursors.
[0107] In one embodiment of the process according to the invention,
a suitable compound comprising iridium or platinum, preferably
iridium, and appropriate carbene ligands, preferably in
deprotonated form as the free carbene or in the form of a protected
carbene, for example as the silver-carbene complex, are
contacted.
[0108] The present invention therefore relates--in one
embodiment--to a process according to the invention wherein the
ligand precursor used is a corresponding Ag-carbene complex.
[0109] In a further preferred embodiment of the process according
to the invention, the ligand precursors used are organic compounds
which are reacted with suitable Ir or Pt comprising compounds. The
carbene can be released from precursors of the carbene ligands by
removing volatile substances, for example lower alcohols such as
methanol or ethanol, for example at elevated temperature and/or
under reduced pressure and/or using molecular sieves which bind the
alcohol molecules eliminated. Corresponding processes are known to
those skilled in the art.
[0110] The present invention also relates to the process according
to the invention wherein the ligand precursor used is a compound of
the general formula (IV)
##STR00046##
wherein R.sup.1, A.sup.1, A.sup.2, A.sup.3, A.sup.4, A.sup.1',
A.sup.2', A.sup.3' and A.sup.4' are each as already defined above
for the compounds of the general formula (I), and R.sup.12 is
defined as follows: R.sup.12 is independently
SiR.sup.13R.sup.14R.sup.15, aryl, heteroaryl, alkyl, cycloalkyl or
heterocycloalkyl, R.sup.13, R.sup.14, R.sup.15 are each
independently aryl, heteroaryl, alkyl, cycloalkyl or
heterocycloalkyl.
[0111] The definitions of aryl, heteroaryl, alkyl, cycloalkyl and
heterocycloalkyl have been specified above.
[0112] In a particularly preferred embodiment, R.sup.12 is alkyl,
especially C.sub.1-C.sub.20-alkyl, preferably
C.sub.1-C.sub.10-alkyl, more preferably C.sub.1-C.sub.8-alkyl, for
example methyl, ethyl, propyl such as n-propyl, isopropyl, butyl
such as n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl or
octyl.
R.sup.12 in the compound of the general formula (IV) is most
preferably methyl or ethyl.
[0113] Compounds of the general formula (IV) are generally
obtainable by processes known to those skilled in the art.
Compounds of the general formula (IV) can be obtained for example
by reacting compounds of the general formula (Va)
##STR00047##
or the corresponding CI or BF.sub.4 salt of formula (Vb)
##STR00048##
wherein X is Cl.sup.- or BF.sub.4.sup.-, with compounds of the
general formula (VI)
HC(OR.sup.12).sub.3 (VI),
or by reacting compounds of the general formula (V) in a first step
with Vilsmeier reagent ((chloromethylene)dimethylammonium chloride)
and a sodium salt selected from NaBF.sub.4, NaCl, NaBr or NaI to
obtain a compound of formula (Vc)
##STR00049##
wherein X.sup.- is BF.sub.4-, Cl.sup.-, Br.sup.- or I.sup.- and in
a second step with R.sup.12OH or M''OR.sup.12, wherein M'' is an
alkali metal salt, preferably Na, and where R.sup.1, A.sup.1,
A.sup.2, A.sup.3, A.sup.4, A.sup.1', A.sup.2', A.sup.3', A.sup.4'
and R.sup.12 are each as already defined above for the compounds of
the general formula (IV) or for the metal-carbene complexes,
wherein the metal is Ir or Pt, comprising one, two or three
bidentate ligands of formula (I) and/or (I').
[0114] This preparation of the compounds of the general formula
(IV) can be effected in the presence or in the absence of a
solvent. Suitable solvents are specified below. In one preferred
embodiment, the compounds of the general formula (IV) are prepared
in substance, or the compound of the general formula (VI) is added
in an excess, such that it functions as a solvent.
[0115] Compounds of the general formulae (V) and (VI) are
commercially available and/or obtainable by processes known to
those skilled in the art; for example, compounds of the general
formula (V) are obtainable by reacting the appropriate chlorides
with the appropriate amines.
[0116] The compounds of the general formula (IV) are prepared
generally at a temperature of 10 to 150.degree. C., preferably 40
to 120.degree. C., more preferably 60 to 110.degree. C.
[0117] The reaction time is generally 2 to 48 hours, preferably 6
to 24 hours, more preferably 8 to 16 hours.
[0118] After the reaction has ended, the desired product can be
isolated and purified by customary processes known to those skilled
in the art, for example filtration, recrystallization, column
chromatography, etc.
[0119] Appropriate compounds, especially complexes, comprising Ir
or Pt, preferably iridium, are known to those skilled in the art.
Particularly suitable compounds comprising platinum or iridium
comprise, for example, ligands such as halides, preferably
chloride, 1,5-cyclooctadiene (COD), cyclooctene (COE), phosphines,
cyanides, alkoxides, pseudohalides and/or alkyl.
[0120] Particularly preferred complexes comprising the appropriate
metal, especially iridium, are selected from the group consisting
of [Ir(COD)Cl].sub.2, [Ir(COE).sub.2Cl].sub.2 IrCl3.times.H.sub.2O,
Ir(acac).sub.3, Ir(COD).sub.2BF.sub.4, Ir(COD).sub.2BARF
(BARF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate)),
Pt(COD)Cl.sub.2, Pt(acac).sub.2,
[Pt(C.sub.6H.sub.10)Cl.sub.2].sub.2, K.sub.2PtCl.sub.6,
Pt(pyridine).sub.2Cl.sub.2, [PtMe.sub.2(SMe.sub.2)].sub.2,
Pt(SMe.sub.2).sub.2Cl.sub.2, Pt(SEt.sub.2).sub.2Cl.sub.2,
Pt(phenanthroline)Cl.sub.2, Pt(NH.sub.3).sub.2Cl.sub.2 and mixtures
thereof.
[0121] The carbene ligand precursors are deprotonated, preferably
before the reaction, for example, by basic compounds known to those
skilled in the art, for example basic metalates, basic metal
acetates, acetylacetonates or alkoxides, or bases such as KOtBu,
NaOtBu, LiOtBu, NaH, silylamides, Ag.sub.2O and phosphazene bases.
Particular preference is given to deprotonating with Ag.sub.2O to
obtain the corresponding Ag-carbene, which is reacted with the
compound comprising M to give the inventive complexes.
[0122] Particularly preferably, the carbene can be released from
precursors of the carbene ligands by removing volatile substances,
for example lower alcohols.
[0123] The process according to the invention for preparing the
metal-carbene complexes, wherein the metal is Ir or Pt, comprising
one, two or three bidentate ligands of formula (I) and/or (I')
according to the present invention using the compounds of the
general formula (IV) has the advantage that the compounds of the
general formula (IV) are stable intermediates which can be handled
readily and can be isolated under standard laboratory conditions.
In addition, the compounds of the general formula (IV) are soluble
in customary organic solvents, such that the preparation of the
inventive metal-carbene complexes, wherein the metal is Ir or Pt,
comprising one, two or three bidentate ligands of formula (I)
and/or (I') in homogeneous solution is possible, such that a workup
of the desired product, i.e. of the metal-carbene complexes,
wherein the metal is Ir or Pt, comprising one, two or three
bidentate ligands of formula (I) and/or (I') is more readily
possible, for example for isolation and/or purification.
[0124] The contacting is preferably effected in a solvent. Suitable
solvents are known per se to those skilled in the art and are
preferably selected from the group consisting of aromatic or
aliphatic solvents, for example benzene, toluene, xylene or
mesitylene, cyclic or acyclic ethers, for example dioxane or THF,
alcohols, esters, amides, ketones, nitriles, halogenated compounds
and mixtures thereof. Particularly preferred solvents are toluene,
xylenes, mesitylene and dioxane.
[0125] The molar ratio of metal-noncarbene complex used to carbene
ligand precursor used is generally 1:10 to 10:1, preferably 1:1 to
1:6, more preferably 1:2 to 1:5.
[0126] The contacting is generally effected at a temperature of 20
to 200.degree. C., preferably 50 to 150.degree. C., more preferably
60 to 150.degree. C.
[0127] The reaction time depends on the desired carbene complex and
is generally 0.02 to 50 hours, preferably 0.1 to 24 hours, more
preferably 1 to 24 hours.
[0128] The metal-carbene complexes, wherein the metal is Ir or Pt,
comprising one, two or three bidentate ligands of formula (I)
and/or (I') obtained after the reaction can optionally be purified
by processes known to those skilled in the art, for example
washing, crystallization or chromatography, and optionally
isomerized under conditions likewise known to those skilled in the
art, for example with acid mediation, thermally or
photochemically.
[0129] Suitable processes for preparing the metal-carbene complex
comprising one, two or three, preferably three, bidentate ligands
of formula (I) and/or (I'), especially suitable processes for
preparing the inventive complexes of formulae (II), (II') and
(II''), wherein at least one ligand L is present (o or o' are 1 or
2), are for example mentioned in WO 2011/073149 A1.
[0130] The resulting complexes may yield different isomers that can
be separated or converted into a form with a major isomer by
isomerization of the mixture.
[0131] Metal-Carbene Complex Comprising One, Two or Three,
Preferably Three, Bidentate Ligands of Formula (I) and/or (I') as
Emitter Material
[0132] According to the present invention, the metal-carbene
complex comprising one, two or three, preferably three, bidentate
ligands of formula (I) and/or (I') are employed in an organic
electronic device, preferably in an OLED. More preferably, the
metal-carbene complex comprising one, two or three, preferably
three, bidentate ligands of formula (I) and/or (I') are employed as
emitter material, preferably as emitter material in the
light-emitting layer of an OLED. Suitable OLEDs are known in the
art and the preferred structures of suitable OLEDs are described
above and--in more detail--below.
[0133] The metal-carbene complex comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I') have
an emission maximum (max) of from 400 to 500 nm. Preferably, the
emitter has an emission maximum (A), which of from 425 nm to 490
nm, more preferably of from 440 nm to 475 nm, preferably with a
FWHM (full width at half maximum) of from 1 nm to 140 nm, more
preferably of from 30 nm to 120 nm, most preferably of from 40 nm
to 80 nm.
[0134] The metal-carbene complex comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I') are
characterized by a high color purity, especially in the blue region
of the electromagnetic spectrum. The preferred CIE-y values of said
metal-carbene complexes according to the present invention are
<035, more preferably<0.30, most preferably <0.25. (CIE
1931 XYZ color space, created by the International Commission on
Illumination (CIE)). The CIE x and y values (coordinates) are
extracted from the spectra according to CIE 1931 as known by a
person skilled in the art.
[0135] The metal-carbene complex comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I') are
preferably phosphorescence emitter showing emission of light by
phosphorescence. However, this does not exclude that the
phosphorescence emitter additionally shows emission of light by
fluorescence.
[0136] The phosphorescence emitter show phosphorescence emission
from triplet excited states, preferably at the operating
temperatures of the OLED. Phosphorescence may be preceded by a
transition from a triplet excited state to an intermediate
non-triplet state from which the emissive decay occurs.
[0137] The emission decay time (intensity reduced to
1/e=0.367879441 times its initial value) of the luminescence
emission of the metal-carbene complex comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I') is
preferably of from 0.5 to 20 micro seconds, more preferably of from
0.5 to 10 micro seconds, most preferably of from 0.5 to 4 micro
seconds.
Further Emitter Materials
[0138] The metal-carbene complex comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I') may
be employed alone as the only emitter material or in a mixture with
one or more metal-carbene complexes comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I')
and/or one or more further emitter materials, preferably in the
light-emitting layer of an OLED. Suitable further emitter materials
are known by a person skilled in the art.
[0139] Suitable further emitter materials are for example:
[0140] Phosphorescence emitter compounds based on metal complexes,
and especially the complexes of the metals Ru, Rh, Ir, Pd and Pt,
in particular the complexes of Ir
[0141] Suitable metal complexes for use in the inventive organic
electronic device, preferably in the OLEDs, are described, for
example, in documents WO 02/60910 A1, US 2001/0015432 A1, US
2001/0019782 A1, US 2002/0055014 A1, US 2002/0024293 A1, US
2002/0048689 A1, EP 1 191 612 A2, EP 1 191 613 A2, EP 1 211 257 A2,
US 2002/0094453 A1, WO 02/02714 A2, WO 00/70655 A2, WO 01/41512 A1,
WO 02/15645 A1, WO 2005/019373 A2, WO 2005/113704 A2, WO
2006/115301 A1, WO 2006/067074 A1, WO 2006/056418, WO 2006121811
A1, WO 2007095118 A2, WO 2007/115970, WO 2007/115981, WO
2008/000727, WO 2010/086089, WO 2012/121936 A2, US 2011/0057559, WO
2011/106344, US 2011/0233528 and WO 2011/157339, WO2008156879,
WO2010068876, US20110233528, WO2012048266, WO2013031662,
WO2013031794.
[0142] Further suitable metal complexes are the commercially
available metal complexes tris(2-phenylpyridine)iridium(III),
iridium(III) tris(2-(4-tolyl)pyridinato-N,C.sup.2'),
bis(2-phenylpyridine)(acetylacetonato)indium(III), indium(III)
tris(1-phenylisoquinoline), indium(III)
bis(2,2'-benzothienyl)(pyridinato-N,C.sup.3')(acetylacetonate),
tris(2-phenylquinoline)iridium(III), iridium(III)
bis(2-(4,6-difluorophenyl)pyridinato-N,C.sup.2)picolinate,
iridium(III) bis(1-phenylisoquinoline)(acetylacetonate),
bis(2-phenylquinoline)(acetylacetonato)iridium(III), iridium(III)
bis(dibenzo[f,h]quinoxaline)-(acetylacetonate), iridium(III)
bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate),
bis[1-(9,9-dimethyl-9H-fluoren-2-yl)isoquinoline](acetylacetonato)indium(-
III), bis(2-phenylbenzo-thiazolato)(acetylacetonato)iridium(III),
bis(2-(9,9-dihexylfluorenyl)-1-pyridine)(acetyl-acetonato)iridium(III),
bis(2-benzo[b]thiophen-2-ylpyridine)(acetylacetonato)iridium(III).
[0143] Preferred further phosphosphorescence emitters are carbene
complexes. Carbene complexes which are suitable phosphorescent blue
emitters are specified in the following publications: WO
2006/056418 A2, WO 2005/113704, WO 2007/115970, WO 2007/115981, WO
2008/000727, WO2009050281, WO2009050290, WO2011051404,
US2011/057559 WO2011/073149, WO2012/121936A2, US2012/0305894A1,
WO2012170571, WO2012170461, WO 2012170463, WO2006121811,
WO2007095118, WO2008156879, WO2008156879, WO2010068876,
US20110057559, WO2011106344, US20110233528, WO2012048266 and
WO2012172482.
[0144] Preferably, the metal-carbene complex comprising one, two or
three, preferably three, bidentate ligands of formula (I) and/or
(I') is employed alone--as the only emitter material, preferably in
the light-emitting layer of an OLED.
[0145] In the case that more than one emitter material is used, for
example in a white OLED, 0.01 to 20% by weight, preferably 0.1 to
10% by weight, more preferably 0.1 to 2% by weight of a red emitter
are employed, 5 to 40% by weight, preferably 10 to 30% by weight,
more preferably 15 to 25% by weight of the metal-carbene complex
according to the present invention as blue emitter are employed and
0.05 to 5% by weight, preferably 0.05 to 3% by weight, more
preferably 0.1 to 1% by weight of a green emitter are employed. The
residual amount to 100% in each emitter system is at least one host
compound. Suitable host compounds for each emitter material are
known to a person skilled in the art.
Host Material
[0146] The metal-carbene complex comprising one, two or three,
preferably three, bidentate ligands of formula (I) and/or (I') or
the mixture of emitter materials mentioned above may be employed,
preferably in the light-emitting layer of an OLED, without further
additional components or with one or more further components in
addition to the emitter material. For example, a fluorescent dye
may be present in the light-emitting layer of an OLED in order to
alter the emission color of the emitter material. In addition--in a
preferred embodiment--one or more host (matrix) materials can be
used. This host material may be a polymer, for example
poly(N-vinylcarbazole) or polysilane. The host material may,
however, likewise be a small molecule, for example
4,4'-N,N'-dicarbazolebiphenyl (CDP=CBP) or tertiary aromatic
amines, for example TCTA.
[0147] Suitable as host material are carbazole derivatives, for
example 4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl (CDBP),
4,4'-bis(carbazol-9-yl)biphenyl (CBP), 1,3-bis(N-carbazolyl)benzene
(mCP), and the host materials specified in the following
applications: WO2008/034758, WO2009/003919.
[0148] Further suitable host materials, which may be small
molecules or (co)polymers of the small molecules mentioned, are
specified in the following publications: WO2007108459 (H-1 to
H-37), preferably H-20 to H-22 and H-32 to H-37, most preferably
H-20, H-32, H-36, H-37, WO2008035571 A1 (Host 1 to Host 6),
JP2010135467 (compounds 1 to 46 and Host-1 to Host-39 and Host-43),
WO2009008100 compounds No. 1 to No. 67, preferably No. 3, No. 4,
No. 7 to No. 12, No. 55, No. 59, No. 63 to No. 67, more preferably
No. 4, No. 8 to No. 12, No. 55, No. 59, No. 64, No. 65, and No. 67,
WO2009008099 compounds No. 1 to No. 110, WO2008140114 compounds 1-1
to 1-50, WO2008090912 compounds OC-7 to OC-36 and the polymers of
Mo-42 to Mo-51, JP2008084913 H-1 to H-70, WO2007077810 compounds 1
to 44, preferably 1, 2, 4-6, 8, 19-22, 26, 28-30, 32, 36, 39-44,
WO201001830 the polymers of monomers 1-1 to 1-9, preferably of 1-3,
1-7, and 1-9, WO2008029729 the (polymers of) compounds 1-1 to 1-36,
WO20100443342 HS-1 to HS-101 and BH-1 to BH-17, preferably BH-1 to
BH-17, JP2009182298 the (co)polymers based on the monomers 1 to 75,
JP2009170764, JP2009135183 the (co)polymers based on the monomers
1-14, WO2009063757 preferably the (co)polymers based on the
monomers 1-1 to 1-26, WO2008146838 the compounds a-1 to a-43 and
1-1 to 1-46, JP2008207520 the (co)polymers based on the monomers
1-1 to 1-26, JP2008066569 the (co)polymers based on the monomers
1-1 to 1-16, WO2008029652 the (co)polymers based on the monomers
1-1 to 1-52, WO2007114244 the (co)polymers based on the monomers
1-1 to 1-18, JP2010040830 the compounds HA-1 to HA-20, HB-1 to
HB-16, HC-1 to HC-23 and the (co)polymers based on the monomers
HD-1 to HD-12, JP2009021336, WO2010090077 the compounds 1 to 55,
WO2010079678 the compounds H1 to H42, WO2010067746, WO2010044342
the compounds HS-1 to HS-101 and Poly-1 to Poly-4, JP2010114180 the
compounds PH-1 to PH-36, US2009284138 the compounds 1 to 111 and H1
to H71, WO2008072596 the compounds 1 to 45, JP2010021336 the
compounds H-1 to H38, preferably H-1, WO2010004877 the compounds
H-1 to H-60, JP2009267255 the compounds 1-1 to 1-105, WO2009104488
the compounds 1-1 to 1-38, WO2009086028, US2009153034,
US2009134784, WO2009084413 the compounds 2-1 to 2-56, JP2009114369
the compounds 2-1 to 2-40, JP2009114370 the compounds 1 to 67,
WO2009060742 the compounds 2-1 to 2-56, WO2009060757 the compounds
1-1 to 1-76, WO2009060780 the compounds 1-1 to 1-70, WO2009060779
the compounds 1-1 to 1-42, WO2008156105 the compounds 1 to 54,
JP2009059767 the compounds 1 to 20, JP2008074939 the compounds 1 to
256, JP2008021687 the compounds 1 to 50, WO2007119816 the compounds
1 to 37, WO2010087222 the compounds H-1 to H-31, WO2010095564 the
compounds HOST-1 to HOST-61, WO2007108362, WO2009003898,
WO2009003919, WO2010040777, US2007224446, WO06128800, WO2012014621,
WO2012105310, WO2012/130709, European patent applications
EP12175635.7 and EP12185230.5 and EP12191408.9 (in particular page
25 to 29 of EP12191408.9), WO2012048266, WO2012145173,
WO2012162325, and EP2551932.
[0149] In a particularly preferred embodiment, one or more
compounds of the general formula (IX) specified hereinafter are
used as host material
##STR00050##
wherein
X is NR, S, O or PR;
[0150] R is aryl, heteroaryl, alkyl, cycloalkyl, or
heterocycloalkyl; A.sup.200 is --NR.sup.206R.sup.207,
--P(O)R.sup.208R.sup.209, --PR.sup.210R.sup.211,
--S(O).sub.2R.sup.212, --S(O)R.sup.213, --SR.sup.214, or
--OR.sup.215; R.sup.221, R.sup.222 and R.sup.223 are independently
of each other aryl, heteroaryl, alkyl, cycloalkyl, or
heterocyclo-alkyl, wherein at least on of the groups R.sup.221,
R.sup.222, or R.sup.223 is aryl, or heteroaryl; R.sup.204 and
R.sup.205 are independently of each other alkyl, cycloalkyl,
heterocycloalkyl, aryl, heteroaryl, a group A.sup.200, or a group
having donor, or acceptor characteristics; n2 and m1 are
independently of each other 0, 1, 2, or 3; R.sup.206, R.sup.207
form together with the nitrogen atom a cyclic residue having 3 to
10 ring atoms, which can be unsubstituted, or which can be
substituted with one, or more substituents selected from alkyl,
cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a group having
donor, or acceptor characteristics; and/or which can be annulated
with one, or more further cyclic residues having 3 to 10 ring
atoms, wherein the annulated residues can be unsubstituted, or can
be substituted with one, or more substituents selected from alkyl,
cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a group having
donor, or acceptor characteristics; and R.sup.208, R.sup.209,
R.sup.210, R.sup.211, R.sup.212, R.sup.213, R.sup.214 and R.sup.215
are independently of each other aryl, heteroaryl, alkyl,
cycloalkyl, or heterocycloalkyl.
[0151] Compounds of formula (IX) and their preparation processes,
such as, for example,
##STR00051##
are described in WO 2010/079051 A1 (in particular pages on 19 to 26
and in tables on pages 27 to 34, pages 35 to 37 and pages 42 to
43).
[0152] Additional host materials on basis of dibenzofurane are, for
example, described in US 2009066226, EP1 885 818 B1, EP 1 970 976,
EP 1 998 388 and EP 2 034 538. Examples of particularly preferred
host materials are shown below:
##STR00052## ##STR00053## ##STR00054## ##STR00055## ##STR00056##
##STR00057##
[0153] In the above-mentioned compounds T is O, or S, preferably O.
If T occurs more than one time in a molecule, all groups T have the
same meaning.
[0154] The more preferred host compounds are shown below:
##STR00058## ##STR00059##
(published in WO2012/130709)
##STR00060##
(published in WO2012/130709),
##STR00061##
(published in WO2012/130709)
##STR00062##
(published in WO2012/130709)
##STR00063##
(published in WO2012/130709)
##STR00064##
(published in WO2012/130709), and
##STR00065##
(published in WO2012/130709); as well as the host materials
published in WO2012048266, WO2012145173, WO2012162325, and
EP2551932.
[0155] The most preferred host compounds are shown below:
##STR00066##
(SH-1; published in WO 2009/008100, example 4),
##STR00067##
(SH-11; disclosed in EP12175635.7 and U.S. 61/669,677),
##STR00068##
(published in WO 2011/004639, compound I-1, synthesis described in
[0163],
##STR00069##
(published in WO2009/003898, compound 4g),
##STR00070##
(SH-4, published in WO 2010/079051, compound 14),
##STR00071##
(SH-5, published in WO 2010/079051, structure on page 22, X.dbd.O)
and
##STR00072##
(SH-12; published in WO 2012/130709).
[0156] The present invention therefore also concerns the organic
electronic device, preferably the OLED, according to the present
invention, wherein the at least one metal-carbene complex
comprising one, two or three, preferably three in the case of Ir
and preferably one in the case of Pt, bidentate ligands of formula
(I) and/or (I') is employed in combination with at least one host
material. Suitable and preferred host materials are mentioned
above. More preferably, the at least one host material comprises at
least one dibenzofuranyl unit and/or at least one
benzimidazo[1,2-a]benzimidazolyl unit and/or at least one
carbazolyl and/or at least one dibenzothiofuranyl unit. Suitable
host materials and preferred host materials comprising at least one
dibenzofuranyl unit and/or at least one
benzimidazo[1,2-a]benzimidazolylunit and/or at least one carbazolyl
and/or at least one dibenzothiofuranyl unit are mentioned above.
The at least one metal-carbene complex comprising one, two or
three, preferably three in the case of Ir and preferably one in the
case of Pt, bidentate ligands of formula (I) and/or (I') which is
employed in combination with at least one host material is
preferably employed in the light-emitting layer of an OLED.
[0157] Preferably, the light-emitting layer comprises at least one
emitter material, which is a metal-carbene complex comprising one,
two or three, preferably three, bidentate ligands of formula (I)
and/or (I') according to the present invention, and at least one
host material. Suitable and preferred emitter materials as well as
suitable and preferred host materials are mentioned above.
[0158] Most preferably, the organic electronic device, preferably
the OLED, comprises a light-emitting layer comprising at least one
metal-carbene complex comprising one, two or three, preferably
three, bidentate ligands of formula (I) and/or (I') as emitter
material in an amount of 5 to 40% by weight, preferably 5 to 30% by
weight, more preferably 5 to 20 by weight, and at least one host
material, preferably at least one host material comprising at least
one dibenzofuranyl unit and/or at least one
benzimidazo[1,2-a]benzimidazolyl unit and/or at least one
carbazolyl and/or at least one dibenzothiofuranyl unit, more
preferably at least one host material selected from the preferred
and most preferred host materials comprising at least one
dibenzofuranyl unit and/or at least one
benzimidazo[1,2-a]benzimidazolyl unit and/or at least one
carbazolyl and/or at least one dibenzothiofuranyl unit mentioned
above, in an amount of 60 to 95% by weight, preferably 70 to 95% by
weight, more preferably 80 to 95% by weight, where the amount of
the at least one emitter material and the at least one host
material adds up to a total of 100% by weight.
[0159] The light-emitting layer may comprise a second host
compound. The second host compound can be one compound or it can be
a mixture of two or more compounds. The carbene complexes
Ir(DPBIC).sub.3 or Ir(DPABIC).sub.3 which are described below may
be added as co-host.
[0160] Mixed matrix materials with two hosts selected from those
hosts mentioned above, or one host from those hosts mentioned above
and one Ir complex as described below, comprise preferably 5% by
weight to 15% by weight of an Ir complex and 60% by weight to 90%
by weight of a further host selected from the hosts as mentioned
above.
##STR00073##
(as described in WO 2005/019373A2)
##STR00074##
(as described as complex fac-Em1 in WO2012/172182 (synthesis:
example 1)).
[0161] The layer thickness of the light-emitting layer in the
inventive OLED is preferably from 1 to 100 nm, more preferably 5 to
60 nm. Preferred OLED structures are mentioned above and--in more
detail--below.
Device Structure--OLED Structure
[0162] Suitable structures of the organic electronic devices are
known to those skilled in the art. Preferred organic electronic
devices are selected from organic light-emitting diodes (OLED),
light-emitting electrochemical cells (LEEC), organic photovoltaic
cells (OPV) and organic field-effect transistors (OFET). More
preferred organic electronic devices are OLEDs.
[0163] The device structures of said OLEDs, LEECs, OPVs and OFETs
have been described above in general terms. In the following, the
device structures of preferred OLEDs (which are preferred
electronic devices according to the present invention) are
described.
[0164] As mentioned above, the present invention preferably relates
to an organic electronic device which is an OLED, wherein the OLED
comprises
(a) an anode, (b) a cathode, (c) a light-emitting layer between the
anode and the cathode, wherein the metal-carbene complex comprising
one, two or three, preferably three, bidentate ligands of formula
(I) and/or (I') is present in the light-emitting layer of the
OLED.
[0165] Preferred metal-carbene complexes comprising one, two or
three, preferably three, bidentate ligands of formula (I) and/or
(I') are mentioned before.
[0166] The layer sequence in the inventive OLED is preferably as
follows:
1. anode (a) 2. hole-transport layer (d) 3. electron/exciton
blocking layer (e) 4. light-emitting layer (c) 5. cathode (b)
[0167] Layer sequences different from the aforementioned
construction are also possible, and are known to those skilled in
the art. For example, it is possible that the OLED does not have
all of the layers mentioned; for example, an OLED with the layers
(a) (anode), (c) (light-emitting layer) and (b) (cathode) and layer
(d) (hole-transport layer) or layer (e) (electron/exciton blocking
layer) are likewise suitable.
[0168] The OLEDs may additionally have a blocking layer for
holes/excitons (f) adjacent to the cathode side of the
light-emitting layer (c) and/or an electron transport layer (g)
adjacent to the cathode side of the blocking layer for
holes/excitons (f), if present, respectively adjacent to the
cathode side of the light-emitting layer (c), if the blocking layer
for holes/excitons (f) is not present.
[0169] The present invention therefore more preferably relates to
an inventive OLED having the following layer sequence:
1. anode (a) 2. hole-transport layer (d) 3. electron/exciton
blocking layer (e) 4. light-emitting layer (c) 5. blocking layer
for holes/excitons (f) 6. electron transport layer (g) 7. cathode
(b)
[0170] In a further embodiment, the inventive OLED, in addition to
layers (a), (b), (c), (d), (e), (f) and (g), comprises at least one
of the further layers mentioned below: [0171] A hole injection
layer (h) between the anode (a) and the hole-transport layer (d);
[0172] an electron injection layer (i) between the
electron-transport layer (g) and the cathode (b).
[0173] It is additionally possible that a plurality of the
aforementioned functions (electron/exciton blocker, hole/exciton
blocker, hole injection, hole conduction, electron injection,
electron conduction) are combined in one layer and are assumed, for
example, by a single material present in this layer.
[0174] Furthermore, the individual layers of the OLED among those
specified above may in turn be formed from two or more layers. For
example, the hole transport layer may be formed from a layer into
which holes are injected from the electrode, and a layer which
transports the holes away from the hole-injecting layer into the
light-emitting layer. The electron transport layer may likewise
consist of a plurality of layers, for example a layer in which
electrons are injected by the electrode, and a layer which receives
electrons from the electron injection layer and transports them
into the light-emitting layer. These layers mentioned are each
selected according to factors such as energy level, thermal
resistance and charge carrier mobility, and also energy difference
of the layers specified with the organic layers or the metal
electrodes. The person skilled in the art is capable of selecting
the structure of the OLEDs such that it is matched optimally to the
organic compounds used as emitter substances in accordance with the
invention.
[0175] In order to obtain particularly efficient OLEDs, for
example, the HOMO (highest occupied molecular orbital) of the
hole-transport layer should be matched to the work function of the
anode, and the LUMO (lowest unoccupied molecular orbital) of the
electron conductor layer should be matched to the work function of
the cathode, provided that the aforementioned layers are present in
the inventive OLEDs.
Hole-Transport Material (d) and/or the Electron/Exciton Blocker
Material (e)
[0176] The hole-transport material and/or the electron/exciton
blocker material in the OLED of the present invention may be an Ir
metal-carbene complex comprising one, two or three, preferably
three, bidentate ligands of formula (III) and/or (III')
##STR00075##
wherein R.sup.1'', R.sup.2'' and R.sup.3'' are each independently
hydrogen, deuterium, a linear or branched alkyl radical, optionally
interrupted by at least one heteroatom, optionally bearing at least
one functional group and having a total of from 1 to 20 carbon
atoms and/or heteroatoms, a substituted or unsubstituted cycloalkyl
radical, optionally bearing at least one functional group and
having from 3 to 20 carbon atoms, a substituted or unsubstituted
heterocyclo alkyl radical, interrupted by at least one heteroatom,
optionally bearing at least one functional group and having a total
of from 3 to 20 carbon atoms and/or heteroatoms, a substituted or
unsubstituted aryl radical, optionally bearing at least one
functional group and having 6 to 30 carbon atoms, a substituted or
unsubstituted heteroaryl radical, interrupted by at least one
heteroatom, optionally bearing at least one functional group and
having a total of from 5 to 18 carbon atoms and/or heteroatoms, a
group with donor or acceptor action, preferably, R.sup.1'',
R.sup.2'' and R.sup.3'' are each independently hydrogen, a linear
or branched alkyl radical, having from 1 to 6 carbon atoms, a
substituted or unsubstituted aryl radical, having from 6 to 30
carbon atoms, a substituted or unsubstituted heteroaryl radical,
having a total of from 5 to 18 carbon atoms and/or heteroatoms, a
group with donor or acceptor action, selected from the group
consisting of halogen radicals, preferably F or Cl, more preferably
F; CF.sub.3, SiPh.sub.3 and SiMe.sub.3; or R.sup.1'' and R.sup.2''
or R.sup.2'' and R.sup.3'' form, independently of each other,
together with a carbon atom to which they are bonded an optionally
substituted saturated or unsaturated or aromatic ring, optionally
interrupted by at least one heteroatom and having a total of from 5
to 18 carbon atoms and/or heteroatoms, and may optionally be fused
to at least one further optionally substituted saturated or
unsaturated or aromatic ring, optionally interrupted by at least
one heteroatom and having a total of from 5 to 18 carbon atoms
and/or heteroatoms; A1'' is CR.sup.4'' or N, preferably CR.sup.4'';
A.sup.2'' is CR.sup.5'' or N, preferably CR.sup.5''; A.sup.3'' is
CR.sup.6'' or N, preferably CR.sup.6''; A.sup.4'' is CR.sup.7'' or
N, preferably CR.sup.7''; A.sup.1''' is CR.sup.4''' or N,
preferably CR.sup.4'''; A.sup.2''' is CR.sup.5''' or N, preferably
CR.sup.5'''; A.sup.3''' is CR.sup.6''' or N, preferably
CR.sup.6'''; A.sup.4''' is CR.sup.7''' or N, preferably
CR.sup.7'''; R.sup.4'', R.sup.5'', R.sup.6'', R.sup.7'',
R.sup.4''', R.sup.5''', R.sup.6''' and R.sup.7''' are each
independently hydrogen, deuterium, a linear or branched alkyl
radical, optionally interrupted by at least one heteroatom,
optionally bearing at least one functional group and having a total
of from 1 to 20 carbon atoms and/or heteroatoms, a substituted or
unsubstituted cycloalkyl radical, optionally bearing at least one
functional group and having from 3 to 20 carbon atoms, a
substituted or unsubstituted heterocyclo alkyl radical, interrupted
by at least one heteroatom, optionally bearing at least one
functional group and having a total of from 3 to 20 carbon atoms
and/or heteroatoms, a substituted or unsubstituted aryl radical,
optionally bearing at least one functional group and having from 6
to 30 carbon atoms, a substituted or unsubstituted heteroaryl
radical, interrupted by at least one heteroatom, optionally bearing
at least one functional group and having a total of from 5 to 18
carbon atoms and/or heteroatoms, a group with donor or acceptor
action, preferably, R.sup.4'', R.sup.5'', R.sup.6'', R.sup.7'',
R.sup.4''', R.sup.5''', R.sup.6''' and R.sup.7''' are each
independently hydrogen, a linear or branched alkyl radical,
optionally bearing at least one functional group, optionally
interrupted by at least one heteroatom and having a total of from 1
to 20 carbon and/or heteroatoms, a substituted or unsubstituted
aryl radical, having from 6 to 30 carbon atoms, a substituted or
unsubstituted heteroaryl radical, having a total of from 5 to 18
carbon atoms and/or heteroatoms, a group with donor or acceptor
action, selected from halogen radicals, preferably F or Cl, more
preferably F; CF.sub.3, CN, SiPh.sub.3 and SiMe.sub.3; or R.sup.4''
and R.sup.5'', R.sup.5'' and R.sup.6'' or R.sup.6'' and R.sup.7''
or R.sup.4''' and R.sup.5''', R.sup.5''' and R.sup.6''' or
R.sup.6''' and R.sup.7''' form, independently of each other,
together with the carbon atoms to which they are bonded, a
saturated or unsaturated or aromatic, optionally substituted ring,
which is optionally interrupted by at least one heteroatom, has a
total of from 5 to 18 carbon atoms and/or heteroatoms, and may
optionally be fused to at least one further optionally substituted
saturated or unsaturated or aromatic ring, optionally interrupted
by at least one heteroatom and having a total of from 5 to 18
carbon atoms and/or heteroatoms.
[0177] Preferred Ir metal-carbene complexes suitable as
hole-transport materials and/or the electron/exciton blocker
materials in the OLED of the present invention are described in
detail in the EP application No. 13162776.2.
[0178] In the case that the OLED comprises a material different
from the materials mentioned before in the hole-transport layer or
in the electron/exciton blocking layer, suitable materials are
mentioned below.
Hole-Transport Layer (d)
[0179] Further suitable hole-transport materials for layer (d) of
the inventive OLED are disclosed, for example, in Kirk-Othmer
Encyclopedia of Chemical Technology, 4th Edition, Vol. 18, pages
837 to 860, 1996. Either hole-transporting molecules or polymers
may be used as the hole-transport material. Customarily used
hole-transporting molecules are selected from the group
consisting
##STR00076##
of
(4-phenyl-N-(4-phenylphenyl)-N-[4-[4-(N-[4-(4-phenylphenyl)phenyl]anil-
ino)phenyl]phenyl]aniline),
##STR00077##
(4-phenyl-N-(4-phenylphenyl)-N-[4-[4-(4-phenyl-N-(4-phenylphenyl)anilino)-
phenyl]phenyl]aniline),
##STR00078##
(4-phenyl-N-[4-(9-phenylcarbazol-3-yl)phenyl]-N-(4-phenylphenyl)aniline),
##STR00079##
1,1',3,3'-tetraphenylspiro[1,3,2-benzodiazasilole-2,2'-3a,7a-dihydro-1,3,-
2-benzodiazasilole],
##STR00080##
(N2,N2,N2',N2',N7,N7,N7',N7'-octakis(p-tolyl)9,9'-spirobi[fluorene]-2,2',-
7,7'-tetramine), 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl
(.alpha.-NPD),
N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine
(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),
N,N'-bis(4-methylphenyl)-N,N'-bis(4-ethylphenyl)[1,1'-(3,3'-dimethyl)biph-
enyl]-4,4'-diamine (ETPD),
tetrakis(3-methylphenyl)-N,N,N',N'-2,5-phenylenediamine (PDA),
.alpha.-phenyl-4-N,N-diphenylaminostyrene (TPS),
p-(diethylamino)benzaldehyde diphenylhydrazone (DEH),
triphenylamine (TPA),
bis[4-(N,N-diethylamino)2-methylphenyl](4-methylphenyl)methane
(MPMP),
1-phenyl-3-[p-(diethylamino)styryl]5-[p-(diethylamino)phenyl]pyra-
zoline (PPR or DEASP), 1,2-trans-bis(9H-carbazol9-yl)-cyclobutane
(DCZB),
N,N,N',N'-tetrakis(4-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine
(TTB), fluorine compounds such as
2,2',7,7'-tetra(N,N-di-tolyl)amino9,9-spirobifluorene (spiro-TTB),
N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)9,9-spirobifluorene
(spiro-NPB) and
9,9-bis(4-(N,N-bis-biphenyl-4-yl-amino)phenyl-9Hfluorene, benzidine
compounds such as
N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine and porphyrin
compounds such as copper phthalocyanines. In addition, polymeric
hole-injection materials can be used such as poly(N-vinylcarbazole)
(PVK), polythiophenes, polypyrrole, polyaniline, self-doping
polymers, such as, for example, sulfonated
poly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl)
(Plexcore.RTM. OC Conducting Inks commercially available from
Plextronics), and copolymers such as
poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) also
called PEDOT/PSS.
[0180] The hole-transport materials mentioned above are
commercially available and/or prepared by processes known by a
person skilled in the art.
[0181] In a preferred embodiment it is possible to use specific
metal carbene complexes as hole-transport materials. Suitable
carbene complexes are, for example, carbene complexes as described
in WO2005/019373A2, WO2006/056418 A2, WO2005/113704, WO2007/115970,
WO2007/115981 and WO2008/000727. One example of a suitable carbene
complex is Ir(DPBIC).sub.3 with the formula:
##STR00081##
The preparation of Ir(DPBIC).sub.3 is for example mentioned in WO
2005/019373 A2. Another example of a suitable carbene complex is
Ir(DPABIC).sub.3
##STR00082##
The preparation of Ir(DPABIC).sub.3 is for example mentioned in
WO2012/172182 (as complex fac-Em1; synthesis: example 1)).
[0182] The hole-transporting layer may also be electronically doped
in order to improve the transport properties of the materials used,
in order firstly to make the layer thicknesses more generous
(avoidance of pinholes/short circuits) and in order secondly to
minimize the operating voltage of the device. Electronic doping is
known to those skilled in the art and is disclosed, for example, in
W. Gao, A. Kahn, J. Appl. Phys., Vol. 94, No. 1, 1 Jul. 2003
(p-doped organic layers); A. G. Werner, F. Li, K. Harada, M.
Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., Vol. 82, No. 25, 23
Jun. 2003 and Pfeiffer et al., Organic Electronics 2003, 4, 89-103
and K. Walzer, B. Maennig, M. Pfeiffer, K. Leo, Chem. Soc. Rev.
2007, 107, 1233. For example it is possible to use mixtures in the
hole-transporting layer, in particular mixtures which lead to
electrical p-doping of the hole-transporting layer. p-Doping is
achieved by the addition of oxidizing materials. These mixtures
may, for example, be the following mixtures: mixtures of the
abovementioned hole transport materials with at least one metal
oxide as doping material, for example MoO.sub.2, MoO.sub.3,
WO.sub.x, ReO.sub.3 and/or V.sub.2O.sub.5, preferably MoO.sub.3
and/or ReO.sub.3, more preferably MoO.sub.3 or mixtures comprising
the aforementioned hole transport materials and one or more
compounds selected from 7,7,8,8-tetracyanoquinodimethane (TCNQ),
2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ),
2,5-bis(2-hydroxyethoxy)-7,7,8,8-tetracyanoquinodimethane,
bis(tetra-n-butylammonium)tetracyanodiphenoquinodimethane,
2,5-dimethyl-7,7,8,8-tetracyanoquinodimethane, tetracyanoethylene,
11,11,12,12-tetracyanonaphtho-2,6-quinodimethane,
2-fluoro-7,7,8,8-tetracyanoquino-dimethane,
2,5-difluoro-7,7,8,8-tetracyanoquinodimethane,
dicyanomethylene-1,3,4,5,7,8-hexafluoro-6H-naphthalen-2-ylidene)malononit-
rile (F6-TNAP), Mo(tfd).sub.3 (from Kahn et al., J. Am. Chem. Soc.
2009, 131 (35), 12530-12531), compounds as described in EP1988587
and in EP2180029 and quinone compounds as mentioned in EP
09153776.1.
[0183] Preferably, the hole-transport layer comprises 50 to 90% by
weight, of the hole-transport material and 10 to 50% by weight of
the doping material, wherein the sum of the amount of the
hole-transport material and the doping material is 100% by
weight.
Electron/Exciton Blocking Layer (e)
[0184] Blocking layers may also be used to block excitons from
diffusing out of the emissive layer.
[0185] Further suitable metal complexes for use as electron/exciton
blocker material are, for example, carbene complexes as described
in WO 2005/019373 A2, WO 2006/056418 A2, WO 2005/113704, WO
2007/115970, WO 2007/115981 and WO 2008/000727. Explicit reference
is made here to the disclosure of the WO applications cited, and
these disclosures shall be considered to be incorporated into the
content of the present application. One example of a suitable
carbene complex is Ir(DPBIC).sub.3 with the formula:
##STR00083##
Another example of a suitable carbene complex is
Ir(DPABIC).sub.3
##STR00084##
Anode (a)
[0186] The anode is an electrode which provides positive charge
carriers. It may be composed, for example, of materials which
comprise a metal, a mixture of different metals, a metal alloy, a
metal oxide or a mixture of different metal oxides. Alternatively,
the anode may be a conductive polymer. Suitable metals comprise the
metals of groups 11, 4, 5 and 6 of the Periodic Table of the
Elements, and also the transition metals of groups 8 to 10. When
the anode is to be transparent, mixed metal oxides of groups 12, 13
and 14 of the Periodic Table of the Elements are generally used,
for example indium tin oxide (ITO). It is likewise possible that
the anode (a) comprises an organic material, for example
polyaniline, as described, for example, in Nature, Vol. 357, pages
477 to 479 (Jun. 11, 1992). Preferred anode materials include
conductive metal oxides, such as indium tin oxide (ITO) and indium
zinc oxide (IZO), aluminum zinc oxide (AlZnO), and metals. Anode
(and substrate) may be sufficiently transparent to create a
bottom-emitting device. A preferred transparent substrate and anode
combination is commercially available ITO (anode) deposited on
glass or plastic (substrate). A reflective anode may be preferred
for some top-emitting devices, to increase the amount of light
emitted from the top of the device. At least either the anode or
the cathode should be at least partly transparent in order to be
able to emit the light formed. Other anode materials and structures
may be used.
[0187] The anode materials mentioned above are commercially
available and/or prepared by processes known by a person skilled in
the art.
Cathode (b)
[0188] The cathode (b) is an electrode which serves to introduce
electrons or negative charge carriers. The cathode may be any metal
or nonmetal which has a lower work function than the anode.
Suitable materials for the cathode are selected from the group
consisting of alkali metals of group 1, for example Li, Cs,
alkaline earth metals of group 2, metals of group 12 of the
Periodic Table of the Elements, comprising the rare earth metals
and the lanthanides and actinides. In addition, metals such as
aluminum, indium, calcium, barium, samarium and magnesium, and
combinations thereof, may be used.
[0189] The cathode materials mentioned above are commercially
available and/or prepared by processes known by a person skilled in
the art.
Further Layers in the Inventive OLED
Blocking Layer for Holes/Excitons (f)
[0190] Among the materials mentioned below as electron transport
materials, some may fulfil several functions. For example, some of
the electron transport materials are simultaneously hole-blocking
materials when they have a low-lying HOMO or exciton-blocking
materials when they have a sufficiently high triplet energy. These
can be used, for example, in the blocking layer for holes/excitons
(f). However, it is likewise possible that the function as a
hole/exciton blocker is also adopted by the layer (g), such that
the layer (f) can be dispensed with.
Electron Transport Layer (g)
[0191] Electron transport layer may include a material capable of
transporting electrons. Electron transport layer may be intrinsic
(undoped), or doped. Doping may be used to enhance conductivity.
Suitable electron-transporting materials for layer (g) of the
inventive OLEDs comprise metals chelated with oxinoid compounds,
such as tris(8-hydroxyquinolato)aluminum (Alq.sub.3), compounds
based on phenanthroline such as
2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA=BCP),
4,7-diphenyl-1,10-phenanthroline (Bphen),
2,4,7,9-tetraphenyl1,10-phenanthroline,
4,7-diphenyl-1,10-phenanthroline (DPA) or phenanthroline
derivatives disclosed in EP1786050, in EP1970371, or in EP1097981,
and azole compounds such as
2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and
3-(4-biphenylyl)-4phenyl-5-(4-t-butylphenyl)-1,2,4-triazole
(TAZ).
[0192] The electron-transport materials mentioned above are
commercially available and/or prepared by processes known by a
person skilled in the art.
[0193] It is likewise possible to use mixtures of at least two
materials in the electron-transporting layer, in which case at
least one material is electron-conducting. Preferably, in such
mixed electron-transporting layers, at least one phenanthroline
compound is used, preferably BCP, or at least one pyridine compound
according to the formula (VIII) below, preferably a compound of the
formula (VIIIa) below. More preferably, in mixed
electron-transporting layers, in addition to at least one
phenanthroline compound, alkaline earth metal or alkali metal
hydroxyquinolate complexes, for example Liq
(8-hydroxyquinolatolithium), are used. Suitable alkaline earth
metal or alkali metal hydroxyquinolate complexes are specified
below (formula VII). Reference is made to WO2011/157779.
[0194] The electron transport layer may also be electronically
doped in order to improve the transport properties of the materials
used, in order firstly to make the layer thicknesses more generous
(avoidance of pinholes/short circuits) and in order secondly to
minimize the operating voltage of the device. Electronic doping is
known to those skilled in the art and is disclosed, for example, in
W. Gao, A. Kahn, J. Appl. Phys., Vol. 94, No. 1, 1 Jul. 2003
(p-doped organic layers); A. G. Werner, F. Li, K. Harada, M.
Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., Vol. 82, No. 25, 23
Jun. 2003 and Pfeiffer et al., Organic Electronics 2003, 4, 89-103
and K. Walzer, B. Maennig, M. Pfeiffer, K. Leo, Chem. Soc. Rev.
2007, 107, 1233. For example, it is possible to use mixtures which
lead to electrical n-doping of the electron-transporting layer.
n-Doping is achieved by the addition of reducing materials. These
mixtures may, for example, be mixtures of the abovementioned
electron transport materials with alkali/alkaline earth metals or
alkali/alkaline earth metal salts, for example Li, Cs, Ca, Sr,
Cs.sub.2CO.sub.3, with alkali metal complexes, for example
8-hydroxyquinolatolithium (Liq), and with Y, Ce, Sm, Gd, Tb, Er,
Tm, Yb, Li.sub.3N, Rb.sub.2CO.sub.3, dipotassium phthalate,
W(hpp).sub.4 from EP 1786050, or with compounds as described in EP1
837 926 B1.
[0195] In a preferred embodiment, the electron transport layer
comprises at least one compound of the general formula (VII)
##STR00085##
in which R.sup.32' and R.sup.33' are each independently F,
C.sub.1-C.sub.8-alkyl, or C.sub.6-C.sub.14-aryl, which is
optionally substituted by one or more C.sub.1-C.sub.8-alkyl groups,
or two R.sup.32' and/or R.sup.33' substituents together form a
fused benzene ring which is optionally substituted by one or more
C.sub.1-C.sub.8-alkyl groups; a and b are each independently 0, 1,
2 or 3, M.sup.1 is an alkaline metal atom or alkaline earth metal
atom, p is 1 when M.sup.1 is an alkali metal atom, p is 2 when
M.sup.1 is an alkali metal atom.
[0196] A very particularly preferred compound of the formula (VII)
is
##STR00086##
which may be present as a single species, or in other forms such as
Li.sub.gQ.sub.g in which g is an integer, for example
Li.sub.6Q.sub.6. Q is an 8-hydroxyquinolate ligand or an
8-hydroxyquinolate derivative.
[0197] In a further preferred embodiment, the electron-transporting
layer comprises at least one compound of the formula (VIII),
##STR00087##
in which R.sup.34', R.sup.35', R.sup.36', R.sup.37', R.sup.34'',
R.sup.35'', R.sup.36'' and R.sup.37'' are each independently
hydrogen, C.sub.1-C.sub.18-alkyl, C.sub.1-C.sub.18-alkyl which is
substituted by E and/or interrupted by D, C.sub.6-C.sub.24-aryl,
C.sub.6-C.sub.24-aryl which is substituted by G,
C.sub.2-C.sub.20-heteroaryl or C.sub.2-C.sub.20-heteroaryl which is
substituted by G, Q is an arylene or heteroarylene group, each of
which is optionally substituted by G; D is --CO--; --COO--; --S--;
--SO--; --SO.sub.2--; --O--; --NR.sup.40'--;
--SiR.sup.45'R.sup.46'--; --POR.sup.47'--;
--CR.sup.38'.dbd.CR.sup.39'--; or --C.ident.C--; E is --OR.sup.44';
--SR.sup.44'; --NR.sup.40'R.sup.41; --COR.sup.43'; --COOR.sup.42';
--CONR.sup.40'R.sup.41'; --CN; or F; G is E,
C.sub.1-C.sub.18-alkyl, C.sub.1-C.sub.18-alkyl which is interrupted
by D, C.sub.1-C.sub.18-perfluoroalkyl, C.sub.1-C.sub.18-alkoxy, or
C.sub.1-C.sub.18-alkoxy which is substituted by E and/or
interrupted by D, in which R.sup.38' and R.sup.39' are each
independently H, C.sub.6-C.sub.18-aryl; C.sub.6-C.sub.18-aryl which
is substituted by C.sub.1-C.sub.18-alkyl or
C.sub.1-C.sub.18-alkoxy; C.sub.1-C.sub.18-alkyl; or
C.sub.1-C.sub.18-alkyl which is interrupted by --O--; R.sup.40' and
R.sup.41' are each independently C.sub.6-C.sub.18-aryl;
C.sub.6-C.sub.18-aryl which is substituted by
C.sub.1-C.sub.18-alkyl or C.sub.1-C.sub.18-alkoxy;
C.sub.1-C.sub.18-alkyl; or C.sub.1-C.sub.18-alkyl which is
interrupted by --O--; or R.sup.40' and R.sup.41' together form a
6-membered ring; R.sup.42' and R.sup.43' are each independently
C.sub.6-C.sub.18-aryl; C.sub.6-C.sub.18-aryl which is substituted
by C.sub.1-C.sub.18-alkyl or C.sub.1-C.sub.18-alkoxy;
C.sub.1-C.sub.18-alkyl; or C.sub.1-C.sub.18-alkyl which is
interrupted by --O--, R.sup.44' is C.sub.6-C.sub.18-aryl;
C.sub.6-C.sub.18-aryl which is substituted by
C.sub.1-C.sub.18-alkyl or C.sub.1-C.sub.18-alkoxy;
C.sub.1-C.sub.18-alkyl; or C.sub.1-C.sub.18-alkyl which is
interrupted by --O--, R.sup.45' and R.sup.46' are each
independently C.sub.1-C.sub.18-alkyl, C.sub.6-C.sub.18-aryl or
C.sub.6-C.sub.18-aryl which is substituted by
C.sub.1-C.sub.18-alkyl, R.sup.47' is C.sub.1-C.sub.18-alkyl,
C.sub.6-C.sub.18-aryl or C.sub.6-C.sub.18-aryl which is substituted
by C.sub.1-C.sub.18-alkyl.
[0198] Preferred compounds of the formula (VIII) are compounds of
the formula (VIIIa)
##STR00088##
in which Q is:
##STR00089##
is H or C.sub.1-C.sub.18-alkyl and R.sup.48'' is H,
C.sub.1-C.sub.18-alkyl or
##STR00090##
[0199] Particular preference is given to a compound of the
formula
##STR00091##
[0200] In a further, very particularly preferred embodiment, the
electron transport layer comprises a compound of the formula
##STR00092##
and a compound ETM-1.
[0201] In a preferred embodiment, the electron transport layer
comprises the compound of the formula (VII) in an amount of 99 to
1% by weight, preferably 75 to 25% by weight, more preferably about
50% by weight, where the amount of the compounds of the formulae
(VII) and the amount of the compounds of the formulae (VIII) adds
up to a total of 100% by weight.
[0202] The preparation of the compounds of the formula (VIII) is
described in J. Kido et al., Chem. Commun. (2008) 5821-5823, J.
Kido et al., Chem. Mater. 20 (2008) 5951-5953 and JP2008-127326, or
the compounds can be prepared analogously to the processes
disclosed in the aforementioned documents.
[0203] It is likewise possible to use mixtures of alkali metal
hydroxyquinolate complexes, preferably Liq, and dibenzofuran
compounds in the electron transport layer. Reference is made to
WO2011/157790. Dibenzofuran compounds A-1 to A-36 and B-1 to B-22
described in WO 2011/157790 are preferred, wherein dibenzofuran
compound
##STR00093##
(A10; =ETM-2 is most preferred.
[0204] In a preferred embodiment, the electron transport layer
comprises Liq in an amount of 99 to 1% by weight, preferably 75 to
25% by weight, more preferably about 50% by weight, where the
amount of Liq and the amount of the dibenzofuran compound(s),
especially ETM-2, adds up to a total of 100% by weight.
[0205] In a preferred embodiment, the electron transport layer
comprises at least one phenanthroline derivative and/or pyridine
derivative.
[0206] In a further preferred embodiment, the electron transport
layer comprises at least one phenanthroline derivative and/or
pyridine derivative and at least one alkali metal hydroxyquinolate
complex.
[0207] In a further preferred embodiment, the electron transport
layer comprises at least one of the dibenzofuran compounds A-1 to
A-36 and B-1 to B-22 described in WO2011/157790, especially
ETM-2.
[0208] In a further preferred embodiment, the electron transport
layer comprises a compound described in WO 2012/111462, WO
2012/147397 and US 2012/0261654, such as, for example, a compound
of formula
##STR00094##
WO 2012/115034, such as for example, such as, for example, a
compound of formula
##STR00095##
Hole Injection Layer (h)
[0209] Generally, injection layers are comprised of a material that
may improve the injection of charge carriers from one layer, such
as an electrode or a charge generating layer, into an adjacent
organic layer. Injection layers may also perform a charge transport
function. The hole injection layer may be any layer that improves
the injection of holes from anode into an adjacent organic layer. A
hole injection layer may comprise a solution deposited material,
such as a spin-coated polymer, or it may be a vapor deposited small
molecule material, such as, for example, CuPc or MTDATA. Polymeric
hole-injection materials can be used such as poly(N-vinylcarbazole)
(PVK), polythiophenes, polypyrrole, polyaniline, self-doping
polymers, such as, for example, sulfonated
poly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl)
(Plexcore.RTM. OC Conducting Inks commercially available from
Plextronics, e.g. Plxecore AJ20-1000), and copolymers such as
poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) also
called PEDOT/PSS.
[0210] The hole injection materials mentioned above are
commercially available and/or prepared by processes known by a
person skilled in the art.
Electron Injection Layer (i)
[0211] The electron injection layer may be any layer that improves
the injection of electrons into an adjacent organic layer.
Lithium-comprising organometallic compounds such as
8-hydroxyquinolatolithium (Liq), CsF, NaF, KF, Cs.sub.2CO.sub.3 or
LiF may be applied between the electron transport layer (g) and the
cathode (b) as an electron injection layer (i) in order to reduce
the operating voltage.
[0212] The electron injection materials mentioned above are
commercially available and/or prepared by processes known by a
person skilled in the art.
[0213] In general, the different layers in the inventive OLED, if
present, have the following thicknesses:
anode (a): 50 to 500 nm, preferably 100 to 200 nm; a hole injection
layer (h): 5 to 100 nm, preferably 20 to 80 nm, hole-transport
layer (d): 5 to 100 nm, preferably 10 to 80 nm, electron/exciton
blocking layer (e): 1 to 50 nm, preferably 5 to 10 nm,
light-emitting layer (c): 1 to 100 nm, preferably 5 to 60 nm, a
hole/exciton blocking layer (f): 1 to 50 nm, preferably 5 to 10 nm,
electron-transport layer (g): 5 to 100 nm, preferably 20 to 80 nm,
electron injection layer (i): 1 to 50 nm, preferably 2 to 10 nm,
cathode (b): 20 to 1000 nm, preferably 30 to 500 nm.
[0214] The person skilled in the art is aware (for example on the
basis of electrochemical studies) of how suitable materials have to
be selected. Suitable materials for the individual layers are known
to those skilled in the art and are disclosed, for example, in WO
00/70655.
[0215] In addition, it is possible that some of the layers used in
the inventive OLED have been surface-treated in order to increase
the efficiency of charge carrier transport. The selection of the
materials for each of the layers mentioned is preferably determined
by obtaining an OLED with a high efficiency and lifetime.
[0216] The inventive organic electronic device, preferably OLED,
can be produced by methods known to those skilled in the art. In
general, the inventive OLED is produced by successive vapor
deposition of the individual layers onto a suitable substrate.
Suitable substrates are, for example, glass, inorganic
semiconductors or polymer films. For vapor deposition, it is
possible to use customary techniques, such as thermal evaporation,
chemical vapor deposition (CVD), physical vapor deposition (PVD)
and others. In an alternative process, the organic layers of the
organic electronic device, preferably OLED, can be applied from
solutions or dispersions in suitable solvents, employing coating
techniques known to those skilled in the art.
[0217] The relative position of the recombination zone of holes and
electrons in the inventive OLED in relation to the cathode and
hence the emission spectrum of the OLED can be influenced, among
other factors, by the relative thickness of each layer. This means
that the thickness of the electron transport layer should
preferably be selected such that the position of the recombination
zone is matched to the optical resonator property of the diode and
hence to the emission wavelength of the emitter. The ratio of the
layer thicknesses of the individual layers in the OLED depends on
the materials used. The layer thicknesses of any additional layers
used are known to those skilled in the art. It is possible that the
electron-conducting layer and/or the holeconducting layer has/have
greater thicknesses than the layer thicknesses specified when they
are electrically doped.
[0218] In a further embodiment the present invention relates to the
use of a metal-carbene complex comprising one, two or three
bidentate ligands of formula (I) and/or (I') in an OLED, preferably
as emitter material. Suitable and preferred metal-carbene complexes
comprising one, two or three bidentate ligands of formula (I)
and/or (I') and suitable and preferred OLEDs are mentioned above.
The emitter material is present in the light-emitting layer of the
OLED.
[0219] Use of at least one metal-carbene complex comprising one,
two or three, preferably three, bidentate ligands of formula (I)
and/or (I') in an OLED, preferably as emitter material makes it
possible to obtain OLEDs with high color purity and high efficiency
and/or high luminous efficacy and/or with high stability and long
lifetimes.
[0220] The organic electronic devices, preferably OLEDs, can be
used in all apparatus in which electroluminescence is useful.
Suitable devices are preferably selected from the group consisting
of stationary visual display units, such as visual display units of
computers, televisions, visual display units in printers, kitchen
appliances, advertising panels, information panels and
illuminations; mobile visual display units such as visual display
units in smartphones, cellphones, tablet computers, laptops,
digital cameras, MP3-players, vehicles, keyboards and destination
displays on buses and trains; illumination units; units in items of
clothing; units in handbags, units in accessories, units in
furniture and units in wallpaper.
[0221] The present invention therefore further relates to apparatus
selected from the group consisting of stationary visual display
units, such as visual display units of computers, televisions,
visual display units in printers, kitchen appliances, advertising
panels, information panels and illuminations; mobile visual display
units such as visual display units in smartphones, cellphones,
tablet computers, laptops, digital cameras, MP3-players, vehicles,
keyboards and destination displays on buses and trains;
illumination units; units in items of clothing; units in handbags,
units in accessories, units in furniture and units in wallpaper,
comprising at least one organic electronic device, preferably at
least one OLED, according to the present invention or comprising at
least one hole transport layer or at least one electron/exciton
blocking layer according to the present invention.
[0222] In a further embodiment, the metal-carbene complexes
comprising one, two or three, preferably three, bidentate ligands
of formula (I) and/or (I') can be used in white OLEDs.
[0223] The OLEDs may further comprise at least one second
light-emitting layer. The overall emission of the OLEDs may be
composed of the emission of the at least two light-emitting layers
and may also comprise white light, as described for example in
EP13160198.1.
[0224] In addition, the metal-carbene complexes comprising one, two
or three, preferably three, bidentate ligands of formula (I) and/or
(I') can be used in OLEDs with inverse structure. The structure of
inverse OLEDs and the materials typically used therein are known to
those skilled in the art.
[0225] It is also possible to stack two OLEDs or to stack three or
more OLEDs ("stacked device concept"). These devices usually use a
transparent charge generating interlayer such as indium tin oxide
(ITO), V.sub.2O.sub.5, or an organic p-n junction.
[0226] The stacked OLED (SOLED) usually includes at least two
individual sub-elements.
[0227] Each sub-element comprises at least three layers: an
electron transport layer, an emitter layer and a hole-transport
layer. Additional layers may be added to a sub-element. Each SOLED
sub-element may include for example a hole injection layer, a hole
transport layer, an electron/exciton blocking layer, an emitter
layer, a hole/exciton blocking layer, an electron transport layer,
an electron injection layer. Each SOLED sub-element may have the
same layer structure or different layer structure from the other
sub-elements.
[0228] Suitable SOLED structures are known by a person skilled in
the art.
[0229] Not only the organic electronic devices as mentioned above
are a subject of the present invention but also all metal-carbene
complex, wherein the metal is Ir or Pt, comprising one, two or
three bidentate ligands of formula (I) and/or (I') as described in
the present application.
[0230] The inventive complexes can be used in the organic
electronic devices, preferably in the OLEDs, of the present
invention in a pure isomeric form or as mixture of cyclometalation
isomers without significant impact on the device performance.
[0231] In a further embodiment, the present invention relates to a
metal-carbene complex, wherein the metal is Ir or Pt, comprising
one, two or three bidentate ligands of formula (I) and/or (I') as
described in the present application, and to a process for
preparing the inventive metal-carbene complex, by contacting
suitable compounds comprising Ir or Pt with appropriate ligands or
ligand precursors. A suitable process is described above.
[0232] The present invention further relates to the use of the
inventive metal-carbene complex, wherein the metal is Ir or Pt,
comprising one, two or three bidentate ligands of formula (I)
and/or (I') as described in the present application in organic
electronic devices, preferably in OLEDs, more preferably as emitter
materials in OLEDs. Suitable organic electronic devices and
suitable OLEDs are described above.
[0233] The following examples are included for illustrative
purposes only and do not limit the scope of the claims.
EXAMPLES
[0234] The examples which follow, more particularly the methods,
materials, conditions, process parameters, apparatus and the like
detailed in the examples, are intended to support the present
invention, but not to restrict the scope of the present
invention.
[0235] All experiments are carried out in protective gas
atmosphere.
[0236] The percentages and ratios mentioned in the examples
below--unless stated otherwise--are % by weight and weight
ratios.
I Device Examples
Production of an OLED
General Procedure
[0237] The ITO substrate used as the anode is cleaned first with
commercial detergents for LCD production (Deconex.RTM. 20NS, and
25ORGAN-ACID.RTM. neutralizing agent) and then in an
acetone/isopropanol mixture in an ultrasound bath. To eliminate
possible organic residues, the substrate is exposed to a continuous
ozone flow in an ozone oven for a further 25 minutes. This
treatment also improves the hole injection properties of the ITO.
Next, the hole injection layer (40 nm) AJ20-1000 from Plexcore is
spun on from solution. Respectively, in device example 12, the hole
injection layer HATCN (10 nm) is applied by vapor deposition.
HATCN: Dipyrazino[2,3-f:2',3'-h]quinoxaline
2,3,6,7,10,11-hexacarbonitrile)
[0238] Thereafter, the organic materials specified below are
applied by vapor deposition to the cleaned substrate at about
10.sup.-7-10.sup.-9 mbar at a rate of approx. 0.5-5 nm/min. The
hole conductor and exciton blocker applied to the substrate is
Ir(DPBIC).sub.3 (devices 1 to 6, 9, 10, 11 and 12) respectively
Ir(DPABIC).sub.3 (devices 7 or 8 or 9) with a thickness of 20 nm
(80 nm in device example 12), of which the first 10 nm (70 nm in
device example 12) are doped with MoO.sub.3 (50 wt.-%:50 wt. %) (90
wt.-% Ir(DPBIC).sub.3:10 wt.-% MoO.sub.3 in device example 12) to
improve the conductivity.
##STR00096##
(for preparation of Ir(DPBIC).sub.3 see Ir complex (7) in the
application WO2005/019373).
##STR00097##
(described as complex fac-Em1 in WO2012/172182 (synthesis: example
1)).
[0239] Subsequently, a mixture of emitter (BE-X), Ir(DPBIC).sub.3
respectively Ir(DPABIC).sub.3, and a host material (the emitter
(BE-1, BE-2, BE-3, BE-4, BE-5, BE-6 or BE-7 or BE-9 or BE-10 or
BE-11), the host material (SH-1, SH-2, SH-3, SH-4, SH-5 or SH-6)
and the relative amounts in % by weight are given in the specific
device examples) is applied by vapor deposition with a thickness of
40 nm (devices 1 to 3 and 5 to 12) respectively 60 nm (device 4).
Subsequently, the host material is applied by vapor deposition with
a thickness of 5 nm as an exciton and hole blocker.
Emitter:
BE-X (X=1, 2, 3, 4, 5, 6, or 7 or 9 or 10):
##STR00098##
[0240] (isomeric mixture of cyclometallation isomers, shown is only
one cyclometallation isomer)
##STR00099##
(isomeric mixture of cyclometallation isomers, shown is only one
cyclometallation isomer)
##STR00100##
(one homoleptic cyclometallation isomer as shown)
##STR00101##
(one heteroleptic cyclometallation isomer as shown; isomer A)
##STR00102##
(one heteroleptic cyclometallation isomer as shown; isomer B)
##STR00103##
(one homoleptic cyclometallation isomer as shown)
##STR00104##
(and second cyclometallation isomer, shown is only one
cyclometallation isomer)
##STR00105##
(one heteroleptic cyclometallation isomer as shown)
##STR00106##
(one heteroleptic cyclometallation isomer as shown)
##STR00107##
(isomeric mixture of cyclometallation isomers, shown are both
cyclometallation isomers)
BE-V: Comparative Emitter:
##STR00108##
[0241] fac-Em1 in WO2011/073149
[0242] The synthesis of complexes BE-1 to BE-7 and BE-9 and BE-11
is described below.
Host Material:
##STR00109##
[0243] (described in WO2009/008100, example 4)
##STR00110##
(described as compound "I-1" in WO2011/004639, synthesis described
in [0161] to [0163] in WO2011/004639)
##STR00111##
(compound "3-1" in "Synthetic example 2" in US2009/066226)
##STR00112##
("Example 4g" in WO2009/003898)
##STR00113##
(Compound no. 14 in WO 2010/079051)
##STR00114##
[0244] described in WO2010/079051, structure on page 22 (X.dbd.O);
synthesis as in example 17 in EP1 885 818 on page 104 in
US2013/0119360)
[0245] Next, as an electron transporter, a mixture of Liq and ETM
(ETM-1 or ETM-2 as specified in the specific device examples) (50
wt.-%: 50 wt.-%) is applied by vapor deposition in a thickness of
25 nm; then a 4 nm KF layer is applied; and finally a 100 nm-thick
Al electrode is applied. All components are adhesive-bonded to a
glass lid in an inert nitrogen atmosphere.
##STR00115##
Electron Transport Material:
ETM-X (X=1 or 2)
##STR00116##
[0246] (compound A-1 in WO 2011/157779)
##STR00117##
(compound A1 in WO 2011/157779; compound A-10 in WO2006/128800)
[0247] To characterize the OLED, electroluminescence spectra are
recorded at different currents and voltages. In addition, the
current-voltage characteristic is measured in combination with the
light output emitted. The light output can be converted to
photometric parameters by calibration with a photometer. The
lifetime t.sub.1/2 of the diode is defined by the time taken for
the luminance to fall to 50% of its initial value. The lifetime
measurement is carried out at a constant current. The CIE.sub.x,y
coordinates are extracted from the spectra according to CIE 1931 as
known in the art.
[0248] For the different emitters, different host materials and
different electron transport materials in the above-described OLED
structure, the following electrooptical data are obtained:
[0249] All data are obtained at 300 nits.
Device 1:
[0250] Compound BE-1 and BE-2 with SH-1
[0251] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-1 (10:15:75)--5 nm SH-1--25 nm ETM-X:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00003 Voltage LumEff EQE Example BE-X ETM-X [V] [lm/W] [%]
CIE x, y Device 1.1 BE-V ETM-1 5.6 15.4 15.5 0.16; 0.29
(comparative) Device 1.2.sup.[1] BE-1 ETM-1 4.0 21.2 17.7 0.15;
0.25 Device 1.3 BE-2 ETM-2 4.1 18.1 16.1 0.15; 0.23 .sup.[1]40 nm
BE-1/Ir(DPBIC).sub.3/SH-1 (30:5:65)
[0252] Result: Inventive devices 1.2 and 1.3 show better color
(CIE.sub.y), luminous efficacy, lower voltage and better EQE
compared with comparative device 1.1 (BE-V).
Device 2:
[0253] Compound BE-1 and BE-2 with SH-2
[0254] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-2 (10:10:80)--5 nm SH-2--25 nm ETM-X:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00004 Voltage LumEff EQE Example BE-X ETM-X [V] [lm/W] [%]
CIE x, y Device 2.1 BE-V ETM-1 3.9 21.2 15.0 0.16; 0.29
(comparative) Device 2.2 BE-1 ETM-1 3.9 23.3 18.4 0.15; 0.25
[0255] Result: Inventive device 2.2 shows better color (CIE.sub.y)
and better EQE and better luminous efficacy compared with
comparative device 2.1 (BE-V).
Device 3
[0256] Compound BE-2, Compound BE-4 and Compound BE-5 with SH-3
[0257] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-3 (10:15:75)--5 nm SH-3--25 nm ETM-2:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00005 Voltage LumEff EQE relative Example BE-X [V] [lm/W]
[%] CIE x, y LT Device 3.1 BE-V 4.1 15.8 11.7 0.15; 0.26 100
(comparative) Device 3.2 BE-2 3.8 21.0 17.5 0.14; 0.23 164 Device
3.3.sup.[1] BE-4 4.0 16.5 13.4 0.15; 0.21 136 Device 3.4.sup.[2]
BE-5 3.9 16.4 12.5 0.15; 0.22 212 .sup.[1]EML: 40 nm
BE-4/Ir(DPBIC).sub.3/SH-3 (20:10:70), .sup.[2]EML: 40 nm
BE-5/Ir(DPBIC).sub.3/SH-3 (20:10:70)
[0258] Result: Inventive devices 3.2, 3.3 and 3.4 show better color
(CIE.sub.y), luminous efficacy, better EQE and better lifetime
compared with comparative device 3.1 (BE-V).
Device 4
[0259] Compound BE-1 with SH-4
[0260] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--60 nm
BE-X/Ir(DPBIC).sub.3/SH-4 (10:5:85)--5 nm SH-4--25 nm ETM-1:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00006 Voltage LumEff Example BE-X [V] [lm/W] CIE x, y
Device 4.1 BE-V 7.5 10.4 0.16; 0.26 (comparative) Device 4.2 BE-1
5.0 15.0 0.16; 0.26
[0261] Result: Inventive device 4.2 shows better voltage and better
luminous efficacy by constant color (CIE) compared with comparative
device 4.1 (BE-V).
Device 5
[0262] Compound BE-2, Compound BE-4 and Compound BE-5 with SH-5
[0263] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-5 (10:5:85)--5 nm SH-5--25 nm ETM-2:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00007 Voltage LumEff EQE Example BE-X [V] [lm/W] [%] CIE
x, y Device 5.1 BE-V 5.5 14.6 15.5 0.16; 0.27 (comparative) Device
5.2 BE-2 4.3 17.9 18.7 0.14; 0.20 Device 5.3.sup.[1] BE-4 3.9 18.7
18.4 0.14; 0.16 Device 5.4.sup.[2] BE-5 3.8 15.7 15.8 0.14; 0.15
.sup.[1]EML: 40 nm BE-4/Ir(DPBIC).sub.3/SH-5 (5:15:80);
.sup.[2]EML: 20 nm BE-5/Ir(DPBIC).sub.3/SH-5 (5:10:85)
[0264] Result: Inventive devices 5.2, 5.3 and 5.4 show better color
(CIE.sub.y), luminous efficacy and better EQE compared with
comparative device 5.1 (BE-V).
Device 6
[0265] Compound BE-2 and Compound BE-4 with SH-6
[0266] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-6 (10:15:75)--5 nm SH-6--25 nm ETM-2:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00008 Voltage LumEff EQE Example BE-X [V] [lm/W] [%] CIEx,
y Device 6.1 BE-V 4.1 17.3 14.4 0.15; 0.25 (comparative) Device 6.2
BE-2 3.6 22.8 18.8 0.14; 0.21 Device 6.3.sup.[1] BE-4 3.8 18.7 17.2
0.14; 0.17 .sup.[1]EML: 40 nm BE-4/Ir(DPBIC).sub.3/SH-6
(5:5:90)
[0267] Result: Inventive devices 6.2 and 6.3 show better color
(CIE.sub.y) and better EQE compared with comparative device 6.1
(BE-V).
Device 7
[0268] Compound BE-5 with SH-5 and with Ir(DPABIC).sub.3
[0269] 40 nm HIL Plexcore AJ20-1000 10 nm
Ir(DPABIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPABIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-5 (10:5:85)--5 nm SH-5--25 nm ETM-2:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00009 Voltage LumEff Example BE-X [V] [lm/W] CIEx, y
Device 7.1 BE-V 5.0 17.0 0.15; 0.26 (comparative) Device
7.2.sup.[1] BE-5 3.5 20.5 0.15; 0.20 .sup.[1]40 nm
BE-5/Ir(DPBIC).sub.3/SH-5 (15:35:50)
[0270] Result: Inventive device 7.2 shows better color (CIE.sub.y)
and better luminous efficacy compared with comparative example
device 7.1 (BE-V).
Further Device (Device 8) Comprising Compound BE-4 with SH-5 and
with Ir(DPABIC).sub.3
[0271] Same device setup as device 7, only BE-X=BE-4 and using 60
nm BE-4/Ir(DPBIC).sub.3/SH-5 (5:10:85) shows even better CIE
coordinates: (0.14; 0.15).
Further Device (Device 9) Comprising Compound BE-7
[0272] By replacement of the emitter materials mentioned in devices
1 to 7 by the emitter material BE7 luminescent organic
light-emitting devices emitting blue light having a high color
purity are obtained.
Device 10:
[0273] Compound BE-9 and BE-10 with SH-3
[0274] 40 nm HIL Plexcore AJ20-1000--10 nm
Ir(DPBIC).sub.3:MoO.sub.3 (50:50)--10 nm Ir(DPBIC).sub.3--40 nm
BE-X/Ir(DPBIC).sub.3/SH-3 (10:15:75)--5 nm SH-3--25 nm ETM-2:Liq
(50:50)--4 nm KF--100 nm Al
TABLE-US-00010 Voltage LumEff EQE relative Example BE-X [V] [lm/W]
[%] CIE x, y LT Device 9.1.sup.[1] BE-V 4.1 15.8 11.7 0.15; 0.26
100 (comparative) Device 9.2 BE-9 4.4 17.1 15.1 0.15; 0.21 170
Device 9.3 BE-10 4.3 18.4 15.6 0.15; 0.22 180 .sup.[1]EML: 40 nm
BE-V/Ir(DPBIC).sub.3/SH-3 (10:15:75)
[0275] Result: Inventive devices 9.2 and 9.3 show better color
(CIE.sub.y), luminous efficacy, better EQE and better lifetime
compared with comparative device 9.1 (BE-V).
Further Device (Device 11) Comprising Compound BE-11
[0276] By replacement of the emitter materials mentioned in device
10 by the emitter material BE-11 luminescent organic light-emitting
devices emitting blue light having a high color purity are
obtained.
Device 12:
[0277] Mixture of Compounds BE-3 to BE-6 with SH-3
[0278] 10 nm HIL HATCN--70 nm Ir(DPBIC).sub.3:MoO.sub.3 (90:10)--10
nm Ir(DPBIC).sub.3--40 nm BE-X/Ir(DPBIC).sub.3/SH-3 (10:20:70)--5
nm SH-3--25 nm ETM-2:Liq (50:50)--4 nm KF--100 nm Al
TABLE-US-00011 Voltage LumEff EQE Example BE-X [V] [lm/W] [%] CIEx,
y Device 12 BE-3 to BE-6 3.8 17.4 13.5 0.15; 0.21
[0279] Result: Replacing the solution processed HIL (Plexcore
AJ20-1000) and optimizing the HTL thickness gives similar color
(CIE.sub.y), voltage and EQE as device 3.4, having now all steps
processed in vacuum.
[0280] The inventive compounds can be used in a pure isomeric form
or as mixture of cyclometalation isomers without significant impact
on the device performance.
II Synthesis of Complexes BE-1 to BE-11
General Aspects
Determination of the Photoluminescence Spectra
[0281] The photoluminescence (PL) spectra of the complexes are
measured on thin polymer films doped with the respective complexes.
The thin films are prepared by the following procedure: a 10%-w/w
polymer solution is made by dissolving 1 g of the polymer "PMMA 6N"
(Evonik) in 9 g of dichloromethane, followed by stirring for one
hour. 2 mg of the respective complexes are added to 0.098 g of the
PMMA solution, and stirring continued for one minute. The solutions
are casted by doctor-blading with a film applicator (Model 360
2082, Erichsen) with a 60 .mu.m gap onto quartz substrates
providing thin doped polymer films (thickness ca. 6 .mu.m). The PL
spectra and quantum-yields (Q.Y.) of these films are measured with
the integrating-sphere method using the Absolute PL Quantum Yield
Measurement System (Hamamatsu, Model C9920-02) (excitation
wavelength: 400 nm).
Determination Oft the Lifetime .tau..sub.v
[0282] The lifetime (.tau..sub.v) of the luminescence of the
complexes in the prepared films are measured by the following
procedure: For excitation of the emission a sequence of short laser
pulses (THG Nd-YAG, 355 nm, 1 nsec pulse length, 1 kHz repetition
rate) is used. The emissions are detected by the time-resolved
photon-counting technique in the multi-channel scaling modus using
a combination of photomultiplier, discriminator and a multiscaler
card (FAST ComTec GmbH, Model P7888). The .lamda..sub.max, CIE x,y,
Q.Y., and .tau..sub.v values of the photoluminescence measurements,
and the full width of half maxima (FWHM) of the emission spectra
values are included in the following experimental part.
i) Synthesis of Complexes BE-1 and BE-2
Synthesis of BE-1
a) Synthesis of 5-Bromopyrazin-2-Amine
##STR00118##
[0284] A light yellow solution of 19.0 g (0.20 mol) of
2-aminopyrazine in 40 ml of DMF and 120 ml of acetonitrile, and a
light yellow solution of 30.0 g (0.10 mol) of
1,3-dibromo-5,5-dimethylhydantoin (DBH) in 20 ml of DMF and 180 ml
of acetonitrile are simultaneously added during 30 minutes under
argon from two dropping funnels at -5.degree. C. to pre-cooled 20
ml of acetonitrile. After addition the resulting brown solution is
treated with 40 ml of a 10%-solution of sodium thiosulfate at
-5.degree. C. providing a brown suspension and stirring continued
until room temperature is reached. The reaction mixture is
concentrated under vacuum and 180 ml of aqueous 2%-solution of
sodium carbonate added, followed by the addition of 10 g of
Hyflo.RTM. filter aid. The mixture is stirred for 30 minutes,
filtered, and four times extracted with a 3:2-mixture of ethyl
acetate and hexane. The combined organic phases are dried over
sodium sulfate and concentrated under vacuum, providing a dark oil
which is further suspended in hexane and filtered giving a tacky
solid. After drying under vacuum at 60.degree. C. a viscous oil is
obtained which is dissolved in 100 ml of ethyl acetate and the
resulting suspension filtered through a 5 cm layer of silica gel
followed by rinsing the silica gel with 200 ml of ethyl acetate.
The reddish brown solution is treated with activated charcoal
DARCO.RTM. KB-G and stirred at room temperature during 24 hours
followed by filtration and concentration under vacuum, giving the
title product as light yellow viscous oil (yield: 25.0 g (72%)).
.sup.1H-NMR (400 MHz, d.sub.6-DMSO): .delta.=6.64 (s, 1H), 7.68 (s,
1H), 8.03 (s, 1H).
b) Synthesis of 5-ethylpyrazin-2-amine
##STR00119##
[0286] 28.7 g (165 mmol) of 5-bromopyrazin-2-amine and 1.78 g (3.28
mmol) of [1,3-bis(diphenylphosphino)propane]dichloronickel(II) are
suspended in 400 ml of dioxane at room temperature under argon. 300
g of a 15 wt %-solution (1.1 M) of diethylzinc in toluene are
slowly added at 12.degree. C. during 90 minutes giving a turbid
brown solution. The reaction temperature is raised to 21.degree. C.
during one hour and the reaction completed by stirring at
21.degree. C. for an 90 minutes. 30 ml of methanol are slowly added
by controlling the temperature to 21.degree. C. by cooling. The
resulting solution is concentrated under vacuum and further
suspended in 600 ml of toluene followed by the addition of 50 g of
Hyflo.RTM. filter aid. The mixture is stirred during 30 minutes and
filtered over a layer of Hyflo.RTM. filter aid. The solid filter
residue is washed first with 1000 ml of toluene and 1000 ml of
ethyl acetate and the combined filtrates concentrated under vacuum.
An additional amount of crude product is obtained by washing the
solid filter residue with 1500 ml of a 90:10-mixture of
dichloromethane/methanol and concentrating the filtrate under
vacuum. The concentrated fractions are each suspended in
dichloromethane followed by filtration and concentration of the
filtrates under vacuum giving the title product as light beige
viscous oil (yield: 20.1 g (99%)). .sup.1H-NMR (400 MHz,
CDCl.sub.3): .delta.=1.26 (t, 3H), 2.70 (q, 2H), 4.36 (br. s, 2H),
7.88 (s, 1H), 7.99 (s, 1H).
c) Synthesis of 3-bromo-5-ethyl-pyrazin-2-amine
##STR00120##
[0288] 21.0 g (0.171 mol) of 5-ethylpyrazin-2-amine and 14.3 g
(0.181 mol) of pyridine are dissolved in 600 ml of dioxane. 27.35 g
(0.171 mol) of bromine are slowly added at room temperature during
30 minutes during which the temperature rises to 39.degree. C. The
brown reaction mixture is further stirred during 20 minutes and
quenched with 20 ml of water and cooled down under stirring to
28.degree. C. during 15 minutes. The organic phase is separated and
filtered through silica gel (4 cm layer). The organic phase is
separated and filtered through a 4 cm layer of silica gel followed
by rinsing with 50 ml of dioxane. The filtrate is concentrated
under vacuum giving the title product as colorless oil (yield: 18.3
g (53%)). .sup.1H-NMR (400 MHz, d.sub.6-DMSO): .delta.=1.23 (t,
3H), 2.65 (q, 2H), 5.16 (br. s, 2H), 7.78 (s, 1H).
d) Synthesis of 5-ethyl-N2,N3-diphenyl-pyrazine-2,3-diamine
##STR00121##
[0290] 10.1 g (50.0 mmol) of 3-bromo-5-ethyl-pyrazin-2-amine and
465 g of aniline are heated under argon at 146.degree. C. during 28
hours. The brown suspension is concentrated under vacuum and the
residue treated with water followed by acidification with aqueous
HCl giving a dark suspension which is vigorously stirred during 15
minutes. The mixture is treated with 200 ml of hexane and stirring
vigorously continued during one hour. The liquid phase is separated
and the tacky residue taken up in dichloromethane and extracted two
times with 100 ml of water. The organic layer is concentrated under
vacuum and the residue dissolved in toluene followed by filtration
through a 4 cm layer of silica gel and additional rinsing of the
silica gel layer with plenty of toluene. The combined organic
phases are concentrated under vacuum and further purified by
chromatography (silica gel, toluene/hexane). The title product is
obtained as light brown clear viscous oil (yield: 6.1 g (42%)).
[0291] .sup.1H-NMR (400 MHz, d.sub.6-DMSO): .delta.=1.22 (t, 3H),
2.57 (q, 2H), 6.92-7.02 (m, 2H), 7.26-7.37 (m, 4H), 7.48 (s, 1H),
7.61 (dd, 2H), 7.74 (dd, 2H), 8.42 (s, 1H), 8.51 (s, 1H).
e) Synthesis of 5-ethyl-1,3-diphenyl-imidazo[4,5-b]pyrazin-3-ium
tetrafluoroborate
##STR00122##
[0293] 6.8 g (23.4 mmol) of
5-ethyl-N2,N3-diphenyl-pyrazine-2,3-diamine are suspended under
argon in 80 ml of acetonitrile and cooled down to ice-bath
temperature. 7.5 g (58.5 mmol) of (chloromethylene)dimethylammonium
chloride (Vilsmeier reagent) are added in small portions during
under cooling at 0.degree. C. and stirring continued for two hours.
Stirring is continued over an ice-bath for a further 20 hours
during which the temperature slowly reached 21.degree. C. The brown
solution is treated with 10.3 g (93.8 mmol) of sodium
tetrafluoroborate and stirring continued at 21.degree. C. during 20
hours providing a light brown suspension. The suspension is
filtered and the solid washed with 20 ml of acetonitrile. The
filtrate is concentrated under vacuum giving 16.3 g of a brown
viscous oil which is heated up with 30 ml of ethanol. The brown
solution is cooled down and the resulting suspension further
stirred at 0.degree. C. during 30 minutes followed by filtration
and washing with 20 ml of cold ethanol. The solid is dried under
vacuum giving the title product as beige solid (yield: 4.8 g
(72%)). .sup.1H-NMR (400 MHz, d.sub.6-DMSO): .delta.=1.36 (t, 3H),
3.12 (q, 2H), 7.73-7.87 (m, 6H), 8.00-8.08 (m, 4H), 9.01 (s, 1H),
11.07 (s, 1H).
f) Synthesis of
2-ethoxy-5-ethyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine
##STR00123##
[0295] 4.7 g (12.1 mmol) of
5-ethyl-1,3-diphenyl-imidazo[4,5-b]pyrazin-3-ium tetrafluoroborate
are suspended under argon in 40 ml of ethanol and cooled down to
ice-bath temperature. 3.93 g (12.1 mmol) of a 21 wt % solution of
sodium ethoxide in ethanol are slowly added under cooling during 15
minutes. The ice-bath is removed and stirring continued during 30
minutes giving a light beige suspension. The suspension is filtered
and the solid washed with a small amount of ethanol. The filtrate
is concentrated under vacuum giving the title product as beige
viscous oil (yield: 4.2 g (quantitative). .sup.1H-NMR (400 MHz,
d.sub.6-DMSO): .delta.=0.90 (t, 3H), 1.25 (t, 3H), 2.61 (q, 2H),
3.17 (q, 2H), 7.17 (q, 2H), 7.41 (s, 1H), 7.47 (q, 4H), 7.73 (s,
1H), 8.05 (d, 2H), 8.10 (d, 2H).
g) Synthesis of Complex BE-1
##STR00124##
[0297] 4.0 g (11.6 mmol) of
2-ethoxy-5-ethyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine and 0.97 g
(1.4 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer are
suspended under argon in 30 ml of o-xylene. The suspension is four
times evacuated and backfilled with argon, followed by heating at
134.degree. C. during 140 minutes. The dark brown clear solution is
cooled down to room temperature and diluted with 40 ml of hexane
followed by filtration and washing with 100 ml of hexane. The solid
is three times suspended with 20 ml of ethanol followed by
filtration and washing with 20 ml of ethanol. The solid is further
suspended in hexane followed by filtration and washing four times
with 20 ml of methanol and drying under vacuum. The resulting grey
powder is dissolved in 10 ml of dichloromethane and filtered
through a 4 cm layer of silica gel followed by rinsing with 80 ml
of dichloromethane under the exclusion of light. The combined
filtrate is diluted with 30 ml of ethanol and concentrated under
vacuum to one fifth of the volume giving a light yellow suspension
which is filtered, and the resulting solid further washed with
ethanol. The solid is heated up in a mixture of 30 ml of 2-butanone
and 5 ml of toluene and stirring continued for 30 minutes. The
yellow suspension is cooled down to room temperature, filtered, and
the resulting solid further dried under vacuum giving the title
product as a light yellow powder (yield: 1.33 g (42%)). .sup.1H-NMR
(400 MHz, CDCl.sub.3): .delta.=1.20-1.34 (m, 6H), 1.44-1.62 (m,
6H), 2.70-2.84 (m, 3H), 2.96-3.11 (m, 3H), 6.21-7.27 (2 m and br.
s, 24H), 7.90-8.00 and 8.15-8.25 (2 m, 3H), 8.71-8.80 and 8.81-8.90
(2 m, 3H). APCI-LC-MS (positive, m/z): exact mass of
C.sub.57H.sub.45IrN.sub.21=1090.35. found 1091.2 [M+1]+.
[0298] Photoluminescence data (2% film in PMMA):
.lamda..sub.max=471 nm, CIE x,y=(0.15,0.22), Q.Y.=96%,
.tau..sub.v=3.3 .mu.s.
Synthesis of BE-2
a) Synthesis of 5-isobutylpyrazine-2-amine
##STR00125##
[0300] 14.59 g (0.60 mol) of magnesium shavings are suspended under
argon in 50 ml of tetrahydrofuran. 91.35 g (0.66 mol) of
1-bromo-2-methylpropane in 200 ml of tetrahydrofuran are slowly
added during 45 minutes by carefully regulating the exothermy of
the Grignard reaction by cooling with an ice-bath keeping the
reaction temperature at a maximum of 54.degree. C. The grey
suspension is further stirred during 30 minutes and allowed to cool
down to room temperature. A colorless solution of 40.89 g (0.30
mol) of anhydrous zinc chloride in 200 ml of tetrahydrofuran is
added during 10 minutes and the released exothermy carefully
regulated with an ice-bath keeping the temperature at a maximum of
48.degree. C. The resulting grey thick suspension is further
stirred during 75 minutes until the temperature reaches 25.degree.
C. A solution of 17.4 g (0.10 mol) of 2-bromo-5-aminopyrazine in
200 of tetrahydrofuran and 1.08 g (2.0 mmol) of
[1,3-bis(diphenylphosphino)propane]dichloronickel(II) are
sequentially added and the temperature increased up to 48.degree.
C. during 45 minutes giving a light brown solution. Stirring is
continued for 15 minutes at the same temperature and the solution
cooled down to room temperature. The solution is slowly treated
with 25 ml of water and 40 ml of concentrated HCl followed by
stirring and dilution of the mixture with 300 ml of water. Aqueous
ammonia solution is added until basic pH is reached and the
resulting suspension further stirred together with 400 ml of
toluene and 40 g of Hyflo.RTM. filter aid followed by filtration.
The organic phase is separated and three times extracted with 250
ml of water, followed by drying over sodium sulfate and
concentration under vacuum giving the title product as a light
yellow oil (yield: 12.4 g (82%)). .sup.1H-NMR (400 MHz,
CDCl.sub.3): .delta.=0.89 (d, 6H), 1.92-2.04 (d, 1H), 2.49 (d, 2H),
4.59 (br. s, 2H), 7.79 (s, 1H), 7.94 (s, 1H).
b) Synthesis of 3-bromo-5-isobutyl-pyrazin-2-amine
##STR00126##
[0302] 12.38 g (81.9 mmol) of 5-isobutylpyrazine-2-amine and 6.86 g
(86.7 mmol) of pyridine are dissolved under argon in 100 ml of
dioxane. 13.08 g (81.8 mmol) of bromine are slowly added at a
temperature of 21.degree. C. during 45 minutes, controlling the
temperature by the use of an ice-bath. The brown biphasic solution
is vigorously stirred during 50 minutes and treated with 75 ml of
water. The resulting brown suspension is extracted with 200 ml of
ethyl acetate and the organic phase washed three times with 100 ml
of water, followed by drying over sodium sulfate, filtration and
concentration under vacuum. The resulting dark oil is further
purified by chromatography (silica gel, heptane/ethyl acetate)
giving the title product as a light yellow solid (yield: 14.5 g
(77%)). .sup.1H-NMR (400 MHz, d.sub.6-DMSO): .delta.=0.86 (d, 6H),
1.81-1.97 (m, 1H), 2.40 (d, 2H), 6.44 (s, 2H), 7.82 (s, 1H).
c) Synthesis of 5-isobutyl-N2,N3-diphenyl-pyrazine-2,3-diamine
##STR00127##
[0304] 12.4 g (53.9 mmol) of 3-bromo-5-isobutyl-pyrazin-2-amine and
250 g of aniline are heated under argon at 152.degree. C. during 28
hours. The brown suspension is diluted with 200 ml of toluene and
extracted three times with 200 ml of water, and the organic phase
concentrated under vacuum. The residue is stirred with aqueous 5%
solution of HCl giving a precipitate which is filtered and washed
with water and diluted aqueous ammonia solution. The sticky solid
is dissolved in 300 ml of toluene and extracted with diluted
ammonia solution and three times with 200 ml of water. The organic
phased is dried over sodium sulfate and concentrated under vacuum.
The dark viscous oil is purified by chromatography (silica gel,
hexane/ethyl acetate) giving the title product as light yellow
solid (yield: 8.9 g (52%)). .sup.1H-NMR (400 MHz, d.sub.6-DMSO):
.delta.=0.92 (d, 6H), 1.95-2.11 (m, 1H), 2.41 (d, 2H), 6.92-7.02
(m, 2H), 7.26-7.36 (m, 4H), 7.44 (s, 1H), 7.62 (dd, 2H), 7.71 (dd,
2H), 8.39 (s, 1H), 8.47 (s, 1H).
d) Synthesis of (3-anilino-6-isobutyl-pyrazin-2-yl)-phenyl-ammonium
chloride
##STR00128##
[0306] A yellow suspension of 8.30 g (26.1 mmol) of
5-isobutyl-N2,N3-diphenyl-pyrazine-2,3-diamine and 100 ml of 37%
hydrochlorid acid is stirred at room temperature during two hours
providing a yellow-brownish solution. The solution is filtered and
poured slowly into 300 ml of water leading to a yellow precipitate
which is filtered off and washed with plenty of water. The solid
residue is dried under vacuum giving the title product as a yellow
powder (yield: 9.1 g (99%)).
[0307] .sup.1H-NMR (400 MHz, d.sub.6-DMSO): .delta.=0.92 (d, 6H),
1.96 (m, 1H), 2.41 (d, 2H), 6.94-7.07 (m, 2H), 7.27-7.42 (m, 5H),
7.65 (d, 2H), 7.78 (d, 2H), 8.96 (br. s, 1H), 9.06 (br. s, 1H).
e) Synthesis of
2-ethoxy-5-isobutyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine
##STR00129##
[0309] 4.50 g (12.7 mmol) of
(3-anilino-6-isobutyl-pyrazin-2-yl)-phenyl-ammonium chloride and
56.5 g (0.38 mol) of triethyl orthoformate are heated up under
argon at 120.degree. C. for one hour. The light brown solution is
concentrated under vacuum giving the title product as brown viscous
oil (yield: 4.75 g (quantitative)). .sup.1H-NMR (400 MHz,
d.sub.6-DMSO): .delta.=0.85-0.99 (m, 9H), 1.99-2.14 (m, 1H),
2.37-2.50 (m, 2H), 3.17 (q, 2H), 7.13-7.22 (m, 2H), 7.43-7.52 (m,
5H), 7.73 (s, 1H), 8.03-8.12 (m, 4H).
f) Synthesis of Complex BE-2
##STR00130##
[0311] 4.50 g (12.0 mmol) of
2-ethoxy-5-isobutyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine and 1.01
g (1.5 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer are
suspended under argon in 60 ml of o-xylene. The suspension is four
times evacuated and backfilled with argon, followed by heating at
122.degree. C. during 23 hours. The brown solution is cooled down
to 40.degree. C., filtered, and diluted with 100 ml of heptane,
filtered, and the solution concentrated under vacuum giving a brown
viscous oil. Purification by chromatography (silica gel,
heptane/dichloromethane) delivers a yellow powder which is further
dissolved in 10 ml of dichloromethane and 50 ml of ethanol.
Dichloromethane is stripped off under vacuum and the resulting
yellow suspension filtered. The solid is dissolved in 10 ml of
dichloromethane and 50 ml of acetonitrile. Dichloromethane is
stripped off under vacuum and the light turbid solution further
cooled down over an ice-bath. The thick suspension is filtered and
the solid washed with a small amount of acetonitrile first,
followed by washing with 30 ml of ethanol and 30 ml of hexane. The
same dissolution and precipitation procedure is repeated once and
the resulting solid dried under vacuum giving the title product as
a light yellow solid (yield: 1.56 g, 44%). .sup.1H-NMR (400 MHz,
CDCl.sub.3): .delta.=0.88-0.99 (m, 12H), 1.05-1.15 (m, 6H),
1.90-2.03 and 2.28-2.41 (2 m, 3H), 2.54-2.65 and 2.81-2.90 (2 m,
6H), 6.22-7.27 (br. s+2 m, 24H), 7.85-7.91 and 8.11-8.20 (2 m, 3H),
8.73-8.80 and 8.80-8.88 (2 m, 3H). APCI-LC-MS (positive, m/z):
exact mass of C.sub.63H.sub.57IrN.sub.12=1174.45. found 1175.3
[M+1].sup.+.
[0312] Photoluminescence data (2% film in PMMA):
.lamda..sub.max=470 nm, CIE x,y=(0.15,0.21), Q.Y.=99%,
.tau..sub.v=3.4 .mu.s).
ii) Synthesis of Complexes BE-3, BE-4, BE-5 and BE-6
Synthesis of Intermediate a
##STR00131##
[0314] A mixture of 32.2 g (0.18 mol) 1-bromopinacolon and 20.5 g
(0.22 mol) in acetonitrile (225 ml) is stirred at 55.degree. C. for
20 h. The reaction mixture is allowed to cool to room temperature
and the solid is filtered off, washed and discarded. The solvent of
the filtrate is removed and the resulting solid is taken up in a
mixture of 5% HCl in 2-propanol (450 ml). The reaction mixture is
stirred for 48 h, then the solid is removed. Diethyl ether is added
and the resulting solid is isolated by filtration and dried under
vacuum to give the title product (yield: 26.2 g (96%)). .sup.1H-NMR
(400 MHz, CDCl.sub.3): .delta.=1.21 (s, 9H), 4.32 (q, 2H), 8.4 (br.
s, 3H).
Synthesis of Intermediate B
##STR00132##
[0316] A mixture of 24.0 g (0.16 mol) intermediate A in water (115
ml) is added in small portions to a suspension of 91 g (0.91 mol)
calcium carbonate in chloroform (300 ml). The reaction mixture is
cooled to 5.degree. C., and then a solution of 32.3 ml (0.36 mol)
2-bromoacetylbromide in chloroform (225 ml) is quickly added. The
resulting mixture is stirred for 1.5 h, the solid is filtered off,
washed with chloroform and discarded. The filtrate is sequentially
washed with a 2N aqueous HCl solution, a sodium carbonate solution
and water. The solvent of the separated organic phase is removed
and the resulting solid is dried under vacuum to give the title
product (yield: 34.5 g (93%)). .sup.1H-NMR (500 MHz,
CD.sub.2Cl.sub.2): .delta.=1.21 (s, 9H), 3.91 (s, 2H), 4.30 (d,
2H), 7.3 (br. s, 1H).
Synthesis of Intermediate C
##STR00133##
[0318] A mixture of 34.1 g (0.15 mol) intermediate B and 4.26 g (28
mmol) sodium iodide in a solution of 2M ammonia in ethanol (500 ml)
is stirred at 40.degree. C. for 48 h. The solvent of the reaction
mixture is removed and ethyl acetate is added to the residue. The
organic phase is washed with water and then dried over sodium
sulfate. The solvent of the separated organic phase is removed and
the resulting residue is dried under vacuum to give the title
product (yield: 18.6 g (84%)). .sup.1H-NMR (400 MHz,
CD.sub.2Cl.sub.2): .delta.=1.26 (s, 9H), 7.12 (s, 1H), 8.16 (s,
1H), 12.5 (br. s, 1H).
Synthesis of Intermediate D
##STR00134##
[0320] A solution of 12.5 g (78 mmol) bromine in chloroform (60 ml)
is slowly added at 0.degree. C. to a mixture of 12.5 g (82 mmol)
intermediate C and 6.8 g (86 mmol) pyridine in chloroform (350 ml).
The resulting mixture is stirred for a further 60 min at 0.degree.
C. Methylene chloride (400 ml) is added and then a 10% aqueous
sodium thiosulfate solution. The organic layer is separated,
extracted with a 1 M aqueous sodium hydroxide solution and
discarded. The aqueous solution is neutralized with 2 M
hydrochloric acid and extracted with methylene chloride. The
organic phase is dried over sodium sulfate. The solvent of the
organic phase is removed and the resulting residue is dried under
vacuum to give the title product (yield: 8.7 g (46%)). .sup.1H-NMR
(400 MHz, CD.sub.2Cl.sub.2): .delta.=1.27 (s, 9H), 7.22 (s, 1H),
12.7 (br. s, 1H).
Synthesis of Intermediate E
##STR00135##
[0322] A mixture of 8.7 g (38 mmol) intermediate D, 18.0 g (0.19
mol) trimethylammonium chloride and 57 g (0.37 mol) POCl3 are
stirred at 110.degree. C. for 20 h. After cooling to room
temperature the remaining liquid is removed and the residue is
taken up in methylene chloride. The mixture is poured in ice water
and the phases are separated. Water is added to the organic phase
and the liquid is brought to pH 11 by adding 25% aqueous sodium
hydroxide. The organic layer is separated and dried over sodium
sulfate. The solvent of the organic phase is removed and the
resulting residue is dried under vacuum to give the title product
(yield: 5.5 g (71%)). .sup.1H-NMR (500 MHz, CD.sub.2Cl.sub.2):
.delta.=1.37 (s, 9H), 8.33 (s, 1H).
Synthesis of Intermediate F
##STR00136##
[0324] A solution of 9.2 g (45 mmol) intermediate E and 63 g (68
mmol) aniline in o-xylene (25 ml) is stirred at 160.degree. C. for
20 h. After cooling to room temperature the remaining liquid is
removed and the residue is taken up in methylene chloride. The
organic phase is sequentially washed with 20% hydrochloric acid,
25% aqueous sodium hydroxide and water. The organic phase is dried
over sodium sulfate. The solvent of the organic phase is removed
and the resulting residue is purified by column chromatography
(silica, eluent: cyclohexane/ethyl acetate) to give the title
product (yield: 11.3 g (79%)). .sup.1H-NMR (400 MHz,
CD.sub.2Cl.sub.2): .delta.=1.36 (s, 9H), 6.06 (s, 1H), 6.47 (s,
1H), 6.99 (m, 2H), 7.16 (d, 2H), 7.29 (m, 4H), 7.49 (d, 2H), 7.78
(s, 1H).
Synthesis of Intermediate G
##STR00137##
[0326] A solution of 11.2 g (35 mmol) intermediate F in a 1M
solution of HCl in methanol (250 ml) is stirred at room temperature
for 20 h. The solvent is removed and the resulting residue is dried
under vacuum. Triethylorthoformiate (250 ml) is added and the
mixture is stirred at 100.degree. C. for 1 h. The solvent is
removed and the resulting residue is dried to give the title
product (yield: 12.5 g (98%)). .sup.1H-NMR (400 MHz,
CD.sub.2Cl.sub.2): .delta.=1.04 (t, 3H), 1.38 (s, 9H), 3.30 (q,
2H), 7.12-7.19 (m, 2H), 7.26 (s, 1H), 7.41-7.48 (m, 4H), 7.55 (s,
1H), 8.07 (d, 2H), 8.17 (d, 2H).
Synthesis of BE-3, BE-4, BE-5 and BE-6
##STR00138##
[0328] A mixture of 5.0 g (13 mmol) intermediate G and 0.9 g (1.3
mmol) [Ir(cod)Cl].sub.2 in o-xylene (300 ml) is stirred at reflux
for 5 h. The solvent is removed, the residue is taken up in a 1:1
mixture of acetonitrile and acetone (100 ml) and stirred for 16 h.
The solid (containing BE-3-BE-5) is isolated by filtration and and
the isomers are separated and purified by column chromatography on
silica. The solvent of the acetonitrile/acetone filtrate is removed
and the residue (containing BE5-BE-6) is purified by column
chromatography on silica.
##STR00139##
[0329] Yield: 155 mg (5%). .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2):
.delta.=1.30 (s, 27H), 6.2-7.1 (br. m, 12H), 6.65 (d, 3H),
6.72-6.82 (m, 6H), 7.13 (t, 3H), 8.39 (s, 3H), 8.74 (d, 3H).
[0330] PL (2% in PMMA): .mu..sub.max=468 nm, CIE x,y=(0.14,0.20),
Q.Y.=89%, .tau..sub.v=2.9 .mu.s.
##STR00140##
[0331] Yield: 730 mg (23%). .sup.1H-NMR (400 MHz,
CD.sub.2Cl.sub.2): .delta.=1.29 (s, 9H), 1.30 (s, 9H), 1.55 (s,
9H), 6.2-7.2 (m, 24H), 8.09 (s, 1H), 8.38 (s, 1H), 8.40 (s, 1H),
8.71 (d, 1H), 8.74 (d, 1H), 8.82 (d, 1H).
[0332] PL (2% in PMMA): .mu..sub.max=467 nm, CIE x,y=(0.14,0.19),
Q.Y.=99% .tau..sub.v=2.9 .mu.s.
##STR00141##
[0333] Yield: 750 mg (24%). .sup.1H-NMR (400 MHz,
CD.sub.2Cl.sub.2): .delta.=1.30 (s, 9H), 1.55 (s, 9H), 1.56 (s,
9H), 6.2-7.3 (m, 24H), 8.09 (s, 1H), 8.10 (s, 1H), 8.39 (s, 1H),
8.72 (d, 1H), 8.79 (d, 1H), 8.83 (d, 1H).
[0334] PL (2% in PMMA): .mu..sub.max=466 nm, CIE x,y=(0.14,0.18),
Q.Y.=99% .tau..sub.v=2.8 .mu.s.
##STR00142##
[0335] Yield: 180 mg (6%). .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2):
d=1.55 (s, 27H), 6.1-7.3 (m, 24H), 8.10 (s, 3H), 8.82 (d, 3H).
[0336] PL (2% in PMMA): .mu..sub.max=466 nm, CIE x,y=(0.15,0.18),
Q.Y.=96% .tau..sub.v=2.8 .mu.s.
iii) Synthesis of BE-8, BE-9 and BE-10
a) Synthesis of Intermediate B
##STR00143##
[0338] Reagent A: A solution of Isopropenylmagnesiumbromide (0.5 M
in THF, 32.1 mL) is slowly added to a mixture of 3.4 g (32 mmol)
Trimethylborate in dry THF (20 mL) at -78.degree. C. The reaction
is stirred overnight to room temperature. The resulting suspension
is poured into 50 mL saturated ammonium chloride solution between
-10 and 0.degree. C. The clear aqueous solution is extracted three
times with diethyl ether (65 mL). The organic layer is then washed
once with saturated sodium chloride solution (25 mL) and then this
organic layer is dried over magnesium sulfate. The solvent is
removed under vacuum and the white solid is stored under argon.
[0339] .sup.1H-NMR (400 MHz, DMSO): .delta.=1.72 (s, 3H), 5.45 (s,
1H), 5.60 (s, 1H), 7.58 (s, 2H).
[0340] Intermediate B: Then a mixture of 1.44 g (8.02 mmol)
2-Amino-5-brompyrazine 97%, the in advance prepared reagent A (raw
product) and 6.81 g (32.1 mmol) potassium phosphate in 100 mL dry
toluene is purged with argon for 10 minutes. Then, 147 mg (0.160
mmol) Tris(dibenzylidenacetone)dipalladium(0) and 180 mg (0.642
mmol) Tricyclohexylphosphine are added. The reaction is stirred
under reflux overnight. After cooling to room temperature, the
suspension is filtered. The solvent of the filtrate is removed and
the resulting residue is purified by column chromatography (silica,
eluent: toluene/ethyl acetate) to give the intermediate B (yield:
1.01 g (94%)).
[0341] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=2.13 (s,
3H), 4.62 (s, 2H), 5.11 (s, 1H), 5.72 (s, 1H), 7.94 (s, 1H), 8.16
(s, 1H).
b) Synthesis of Intermediate C
##STR00144##
[0343] 1.01 g (7.47 mmol) of compound B are dissolved in ethyl
acetate (50 ml). The reaction is purged with nitrogen, and then
Pd/C 10% (84 mg) is added to the clear, yellow solution. The
suspension is stirred at room temperature overnight at a constant
hydrogen atmosphere. After 12 h hydrogenation there is still
starting material detectable in the reaction mixture, so after
filtration of the reaction mixture over a filter, the filtrate is
treated a second time with Pd/C, 10% (84 mg) and hydrogen at room
temperature overnight. Then the suspension is filtered and the
filtrate is concentrated. The title product C is obtained in
quantitative yield.
[0344] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.23 (d,
3H), 1.24 (d, 3H), 2.93 (sept, 1H), 4.45 (s, 2H), 7.84 (d, 1H),
7.91 (d, 1H).
c) Synthesis of Intermediate D
##STR00145##
[0346] 3.59 g (26.17 mmol) of intermediate C and 2.17 g (27.48
mmol) of pyridine are dissolved in 180 mL of chloroform. The
solution is cooled to 0.degree. C. Then, a solution of 3.97 g
(24.86 mmol) of bromine in 35 mL chloroform is slowly added over
1.5 h. The mixture is stirred for 1.5 h at 0.degree. C. The
reaction was then allowed to warm to room temperature and to stir
overnight.
[0347] The brown reaction mixture is slowly quenched with 150 mL of
saturated sodium thiosulfate solution. This mixture is then stirred
for 30 minutes. Then the mixture is separated in a separation
funnel. The organic layer is washed with water and dried over
sodium sulfate. The filtrate is concentrated and the residue is
filtered over silica with toluene/ethyl acetate. The fractions with
product are collected and concentrated to give the title product D
as brown oil in 79.3% yield (4.26 g).
[0348] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.23 and
1.24 (2d, 6H), 2.86-2.98 (m, 1H), 4.89 (s, 2H), 7.82 (s, 1H).
d) Synthesis of Intermediate E (and F1)
##STR00146##
[0350] 4.26 g (19.7 mmol) of intermediate D are stirred in 210 ml
of aniline under argon atmosphere. The reaction is heated to reflux
and stirred overnight. After cooling to room temperature, the
reaction mixture is filtered under vacuum. The filtrate is
concentrated. After removal of aniline (50.degree. C., 3*10.sup.-2
mbar), the brown residue is suspended in a mixture of
dichloromethane (100 ml) and cyclohexane (300 ml). The suspension
is filtered and the solid is washed with cyclohexane (2.times.100
ml). The solid was washed with water (50 ml, 12 h stirring) and
dried to give the title product F1 (yield: 2.4 g (31%)).
[0351] The dichloromethane/cyclohexane filtrate is concentrated and
the residue is purified via column chromatography (silica, CH/EE)
to obtain intermediate E (1.5 g, 25%).
[0352] Intermediate E: .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2):
.delta.=1.29 and 1.30 (2d, 6H), 2.92-3.02 (sept, 1H), 6.06 (s, 1H),
6.46 (s, 1H), 7.00 (q, 2H), 7.16 (d, 2H), 7.29 (q, 4H), 7.65 (s,
1H),
[0353] intermediate F1: .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2):
.delta.=1.21 and 1.22 (2d, 6H), 2.81-2.97 (sept, 1H), 5.04 (s, 1H),
6.94-7.09 (m, 2H), 7.34 (t, 4H), 7.41 (s, 1H), 7.60 (d, 2H), 7.78
(d, 2H), 8.18 (s, 1H), 8.70 (s, 1H).
e) Synthesis of Intermediate F2
##STR00147##
[0355] 0.65 g (2.1 mmol) of intermediate E are suspended in 17 ml
of hydrochloric acid (32%) at room temperature. The mixture is
stirred overnight under nitrogen atmosphere. The brown lump is
treated in an ultrasonic bath until a green precipitate is formed.
This is filtered and washed with water. The solid is dried at
40.degree. C. overnight. The desired product F2 is obtained as
light yellow solid (0.73 g, 78%).
[0356] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.21 and
1.22 (2d, 6H), 2.81-2.95 (m, 1H), 3.95 (s, 1H), 6.93-7.07 (m, 2H),
7.33 (t, 4H), 7.39 (s, 1H), 7.63 (d, 2H), 7.84 (d, 2H), 9.02 (s,
1H), 9.16 (s, 1H).
f) Synthesis of Intermediate G
##STR00148##
[0358] 589 mg (1.73 mmol) of intermediate F2 are suspended in 24 ml
of triethyl orthoformate. The suspension is stirred at room
temperature overnight. Then the reaction is heated to 70.degree. C.
for 2 h. The brown suspension is filtered under vacuum and the
residue is washed with ethanol. The filtrate is concentrated under
vacuum to give the title product G in 91% yield (0.57 g).
[0359] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.04 (t,
3H), 1.31 and 1.32 (2d, 6H), 2.88 (sept, 1H), 3.29 (q, 2H),
7.10-7.20 (m, 2H), 7.24 (s, 1H), 7.37-7.49 (m, 5H), 8.06 (d, 2H),
8.13 (d, 2H).
g) Synthesis of BE-8, BE-9 and BE-10
##STR00149##
[0361] 500 mg (1.39 mmol) of intermediate G are suspended in 10 ml
of anhydrous o-xylene under argon atmosphere. The mixture is purged
10 minutes with argon. Then 93 mg (0.14 mmol) [Ir(cod)Cl].sub.2 are
added. The reaction is heated to reflux and stirred overnight.
After cooling to room temperature, the mixture is concentrated
under vacuum. The brown residue is suspended in ethanol and then
filtered under vacuum. The solid is washed a few times with
ethanol. After drying at 40.degree. C. overnight, the solid is
purified via column chromatography (silica, eluent:
cyclohexane/ethyl acetate) to yield BE-8, BE-9 and BE-10.
##STR00150##
[0362] 30 mg (10%) BE-8
[0363] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.20 (d,
6H), 1.23-1.30 (m, 12H), 3.04 (sept, 3H), 6.48 (m, 7H), 6.63 (d,
4H), 6.73-6.82 (q, 7H), 7.13 (t, 3H), 7.13-7.52 (m, 3H), 8.23 (s,
3H), 8.74 (d, 3H).
[0364] PL (2% PMMA): .lamda..sub.max=469 nm, CIE (x;y)=0.15;0.21,
QY=88%, .tau..sub.v=3.3 .mu.s
##STR00151##
[0365] 89 mg (28%) BE-9
[0366] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.20 (m,
6H), 1.25-1.50 (m, 12H), 2.97-3.10 (m, 2H), 3.22-3.34 (septet, 1H),
6.25-7.32 (m, 10H), 6.65 (d, 4H), 6.72-6.84 (m, 7H), 7.09-7.19 (m,
4H), 7.92 (s, 1H), 8.22 and 8.23 (2s, 2H), 8.73 (t, 2H), 8.83 (d,
1H).
[0367] PL (2% PMMA): .lamda..sub.max=468 nm, CIE (x;y)=0.15;0.21,
QY=86%, .tau..sub.v=3.2 .mu.s
##STR00152##
[0368] 78 mg (25%) BE-10
[0369] .sup.1H-NMR (400 MHz, CD.sub.2Cl.sub.2): .delta.=1.25-1.50
(m, 18H), 2.97-3.10 (septet, 1H), 3.22-3.34 (m, 2H), 6.25-7.42 (m,
10H), 6.65 (d, 4H), 6.72-6.84 (m, 6H), 7.09-7.19 (m, 4H), 7.92 (d,
2H), 8.23 (s, 1H), 8.73 (d, 1H), 8.83 (t, 2H).
[0370] PL (2% PMMA): .lamda..sub.max=467 nm; CIE (x;y)=0.15;0.19;
QY=89%; .tau..sub.v=3.1 .mu.s.
iv) Synthesis of BE-11 and BE-7
a) Synthesis of BE-11
##STR00153##
[0372] A mixture of 0.55 g (1.47 mmol)
2-ethoxy-5-isobutyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine and 0.55
g (1.47 mmol) Pt(cod)Cl.sub.2 in 20 ml o-xylene is heated to
110.degree. C. for 2 hours. 0.30 g (1.47 mmol) silver
acetylacetonate is added and the resulting reaction mixture is
heated to 110.degree. C. for a further 16 hours. After cooling to
RT, the solvent is removed under vacuum. The residue is taken up in
dichloromethane, and silica is added. The mixture is stirred for 30
min, then the solid is filtered off. The solvent of the filtrate is
removed, and the residue is purified by chromatography (silica gel,
toluene), yielding both isomers as yellow solids.
[0373] Isomer 1 (yield: 67 mg, 7%).
[0374] .sup.1H-NMR (CD.sub.2Cl.sub.2): .delta.=0.93 (d, 6H), 1.36
(s, 3H), 2.02 (s, 3H), 2.06 (sept, 1H), 2.69 (d, 2H), 5.37 (s, 1H),
7.09 (dt, 1H), 7.19 (dt, 1H), 7.56-7.67 (m, 5H), 7.75-7.90 (m, 1H),
8.18-8.25 (m, 1H), 8.29 (s, 1H).
[0375] PL (2% in PMMA): .lamda..sub.max=487 nm, CIE
x,y=(0.22,0.36), Q.Y.=67% .tau..sub.v=3.5 .mu.s.
[0376] Isomer 2 (yield: 53 mg, 6%).
[0377] .sup.1H-NMR (CD.sub.2Cl.sub.2): .delta.=1.01 (d, 6H), 1.36
(s, 3H), 2.02 (s, 3H), 2.28 (sept, 1H), 2.84 (d, 2H), 5.37 (s, 1H),
7.09 (dt, 1H), 7.20 (dt, 1H), 7.56-7.71 (m, 5H), 7.73-7.90 (m, 1H),
8.16 (s, 1H), 8.26-8.34 (m, 1H).
[0378] PL (2% in PMMA): .lamda..sub.max=482 nm, CIE
x,y=(0.21,0.33), Q.Y.=52% .tau..sub.v=3.1 .mu.s.
b) Synthesis of BE-7
##STR00154##
[0380] BE-7 is prepared in the same manner as BE-11 with the only
difference that
2-ethoxy-5-isopropyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine is
employed instead of
2-ethoxy-5-isobutyl-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine.
* * * * *