U.S. patent application number 16/300597 was filed with the patent office on 2019-12-12 for oxo-nitrogenated iron complex, catalytic system comprising said oxo-nitrogenated iron complex and process for the (co)polymeriza.
The applicant listed for this patent is Versalis S.p.A.. Invention is credited to Giuseppe LEONE, Francesco MASI, Guido PAMPALONI, Giovanni RICCI, Anna SOMMAZZI.
Application Number | 20190374932 16/300597 |
Document ID | / |
Family ID | 57045300 |
Filed Date | 2019-12-12 |
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United States Patent
Application |
20190374932 |
Kind Code |
A1 |
PAMPALONI; Guido ; et
al. |
December 12, 2019 |
OXO-NITROGENATED IRON COMPLEX, CATALYTIC SYSTEM COMPRISING SAID
OXO-NITROGENATED IRON COMPLEX AND PROCESS FOR THE
(CO)POLYMERIZATION OF CONJUGATED DIENES
Abstract
An oxo-nitrogenated iron complex having general formula (I) or
(II) wherein: R.sub.1 and R.sub.2 identical or different, represent
a hydrogen atom; or are selected from linear or branched,
optionally halogenated C.sub.1-C.sub.20, preferably
C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl
groups, optionally substituted aryl groups; R.sub.3, identical or
different, represent a hydrogen atom; or are selected from linear
or branched, optionally halogenated C.sub.1-C.sub.20, preferably
C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl
groups, f optionally substituted aryl groups; X.sub.1 and X.sub.2,
identical or different, represent a halogen atom such as, for
example, chlorine, bromine, j iodine; or are selected from linear
or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl
groups, --OCOR.sub.4 groups or --OR.sub.4 groups wherein R.sub.4 is
selected from linear or branched C.sub.1-C.sub.20, preferably
C.sub.1-C.sub.15, alkyl groups. Said oxo-nitrogenated iron complex
having general formula (I) or (II) can be advantageously used in a
catalytic system for the (co)polymerization of conjugated dienes.
##STR00001##
Inventors: |
PAMPALONI; Guido;
(Pontedera, IT) ; SOMMAZZI; Anna; (Novara, IT)
; RICCI; Giovanni; (Parma, IT) ; MASI;
Francesco; (S. Angelo Lodigiano, IT) ; LEONE;
Giuseppe; (Milano, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Versalis S.p.A. |
San Donato Milanese |
|
IT |
|
|
Family ID: |
57045300 |
Appl. No.: |
16/300597 |
Filed: |
May 29, 2017 |
PCT Filed: |
May 29, 2017 |
PCT NO: |
PCT/IB2017/053142 |
371 Date: |
November 12, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 2531/842 20130101;
B01J 31/20 20130101; C08F 136/04 20130101; C08F 4/70 20130101; C08F
36/06 20130101; C08F 36/08 20130101; C07F 15/025 20130101; B01J
2531/31 20130101; B01J 2531/847 20130101; C08F 4/52 20130101; C08F
4/7008 20130101; C08F 4/7083 20130101 |
International
Class: |
B01J 31/20 20060101
B01J031/20; C08F 4/70 20060101 C08F004/70; C08F 4/52 20060101
C08F004/52; C08F 36/06 20060101 C08F036/06; C08F 36/08 20060101
C08F036/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2016 |
IT |
102016000055704 |
Claims
1. An oxo-nitrogenated iron complex having general formula (I) or
(II): ##STR00019## wherein: R.sub.1 and R.sub.2, identical or
different, represent a hydrogen atom; or are selected from linear
or branched, optionally halogenated C.sub.1-C.sub.20 alkyl groups,
optionally substituted cycloalkyl groups, or optionally substituted
aryl groups; R.sub.3, identical or different, represent a hydrogen
atom, or are selected from linear or branched, optionally
halogenated C.sub.1-C.sub.20 alkyl groups, optionally substituted
cycloalkyl groups, or optionally substituted aryl groups; X.sub.1
and X.sub.2, identical or different, represent a halogen atom; or
are selected from linear or branched C.sub.1-C.sub.20 alkyl groups,
--OCOR.sub.4 groups or --OR.sub.4 groups wherein R.sub.4 is
selected from linear or branched C.sub.1-C.sub.20 alkyl groups.
2. Oxo-nitrogenated iron complex having general formula (I) or (II)
according to claim 1, wherein: R.sub.1 and R.sub.2, mutually
identical, are selected from linear or branched C.sub.1-C.sub.20
alkyl groups; R.sub.3, mutually identical, are selected from aryl
groups optionally substituted with linear or branched
C.sub.1-C.sub.20 alkyl groups; X.sub.1 and X.sub.2, mutually
identical, are a halogen atom.
3. A catalytic system for the (co) polymerization of conjugated
dienes comprising: a) at least one oxo-nitrogenated iron complex
having general formula (I) or (II) as claimed in claim 1; b) at
least one co-catalyst selected from organic compounds of an element
M' different from carbon, said element M' being selected from
elements belonging to groups 2, 12, 13, or 14 of the Periodic Table
of the Elements.
4. A catalytic system for the (co)polymerization of conjugated
dienes according to claim 3, wherein said co-catalyst (b) is
selected from (b.sub.1) aluminum alkyls having general formula
(III): Al(X').sub.n(R.sub.5).sub.3-n (III) wherein X' represents a
halogen atom; R.sub.5 is selected from linear or branched
C.sub.1-C.sub.20 alkyl groups, cycloalkyl groups, or aryl groups,
said groups being optionally substituted with one or more atoms of
silicon or germanium; and n is an integer ranging from 0 to 2.
5. A catalytic system for the (co)polymerization of conjugated
dienes according to claim 3, wherein said co-catalyst (b) is
selected from (b.sub.2) organo-oxygenated compounds of an element
M' different from carbon belonging to groups 13 or 14 of the
Periodic Table of Elements.
6. A catalytic system for the (co)polymerization of conjugated
dienes according to claim 3, wherein said co-catalyst (b) is
selected from (b.sub.3) compounds or mixtures of organometallic
compounds of an element M' different from carbon able to react with
the oxo-nitrogenated iron complex having general formula (I) or
(II), extracting from this a .sigma.-linked substituent X.sub.1 or
X.sub.2, to form on the one hand at least one neutral compound, and
on the other hand an ionic compound consisting of a cation
containing the metal (Fe) coordinated by the ligand, and an organic
non-coordinating anion containing the metal M', whose negative
charge is delocalized on a multicentric structure.
7. A catalytic system for the (co)polymerization of conjugated
dienes according to claim 4, wherein said aluminum alkyls (b.sub.1)
having general formula (III) are di-ethyl-aluminum chloride (DEAC),
mono-ethyl-aluminum dichloride (EADC), or ethyl
aluminum-sesquichloride (EASC).
8. A catalytic system for the (co) polymerization of conjugated
dienes according to claim 5, wherein said organo-oxygenated
compounds (b.sub.2) are selected from aluminoxanes having general
formula (IV):
(R.sub.6).sub.2--Al--O--[--Al(R.sub.7)--O-].sub.p-Al--(R).sub.2
(IV) wherein R.sub.6, R.sub.7 and R.sub.8, identical or different,
represent a hydrogen atom, a halogen atom; or are selected from
linear or branched C.sub.1-C.sub.20 alkyl groups, cycloalkyl
groups, or aryl groups, said groups being optionally substituted
with one or more atoms of silicon or germanium; and p is an integer
ranging from 0 to 1000.
9. A catalytic system for the (co)polymerization of conjugated
dienes according to claim 8, wherein said organo-oxygenated
compound (b.sub.2) is methylaluminoxane (MAO).
10. A catalytic system for the (co)polymerization of conjugated
dienes according to claim 6, wherein said compounds or mixtures of
compounds (b.sub.3) are selected from organic compounds of aluminum
or boron, including those represented by the following general
formulae: [(R.sub.C).sub.WH.sub.4-W].[B(R.sub.D).sub.4]--;
B(R.sub.D).sub.3; Al(R.sub.D).sub.3; B(R.sub.D).sub.3Pyr;
[Ph.sub.3C]+.[B(R.sub.D).sub.4]--;
[(R.sub.C).sub.3PyrH]+.[B(R.sub.D).sub.4]--;
[Li]+.[B(R.sub.D).sub.4]--; [Li]+.[Al(R.sub.D).sub.4]-- wherein w
is an integer ranging from 0 to 3, each R.sub.C group independently
represents an alkyl group or an aryl group having from 1 to 10
carbon atoms and each R.sub.D group independently represents an
aryl group partially or totally fluorinated, having from 6 to 20
carbon atoms, and Pyr represents a pyrrolyl radical optionally
substituted.
11. A (co)polymerization process of conjugated dienes, wherein the
catalytic system according to claim 3 is used.
12. A (co)polymerization process according to claim 11, wherein
said conjugated dienes are 1,3-butadiene or isoprene.
13. A polymerization process of 1,3-butadiene or isoprene, wherein
the catalytic system according to claim 3 is used.
14. Oxo-nitrogenated iron complex having general formula (I) or
(II) according to claim 1, wherein: R.sub.1 and R.sub.2, identical
or different, represent a hydrogen atom; or are selected from
linear or branched, optionally halogenated C.sub.1-C.sub.15 alkyl
groups, optionally substituted cycloalkyl groups, or optionally
substituted aryl groups; R.sub.3, identical or different, represent
a hydrogen atom, or are selected from linear or branched,
optionally halogenated C.sub.1-C.sub.15 alkyl groups, optionally
substituted cycloalkyl groups, or optionally substituted aryl
groups; X.sub.1 and X.sub.2, identical or different, represent a
halogen atom; or are selected from linear or branched
C.sub.1-C.sub.15 alkyl groups, --OCOR.sub.4 groups or --OR.sub.4
groups wherein R.sub.4 is selected from linear or branched
C.sub.1-C.sub.15 alkyl groups.
15. Oxo-nitrogenated iron complex having general formula (I) or
(II) according to claim 1, wherein: R.sub.1 and R.sub.2, mutually
identical, are a methyl group; R.sub.3, mutually identical, are
selected from aryl groups optionally substituted with one or more
methyl, ethyl, tert-butyl or iso-propyl groups; X.sub.1 and
X.sub.2, mutually identical, are a halogen atom of chlorine,
bromine, or iodine.
16. A catalytic system for the (co) polymerization of conjugated
dienes comprising: at least one oxo-nitrogenated iron complex
having general formula (I) or (II) as claimed in claim 2; at least
one co-catalyst selected from organic compounds of an element M'
different from carbon, said element M' being selected from elements
belonging to groups 2, 12, 13, or 14 of the Periodic Table of the
Elements.
17. A catalytic system for the (co) polymerization of conjugated
dienes comprising: at least one oxo-nitrogenated iron complex
having general formula (I) or (II) as claimed in claim 1 wherein
said element M' is selected from: boron, aluminum, zinc, magnesium,
gallium, or tin.
Description
[0001] The present invention relates to an oxo-nitrogenated iron
complex.
[0002] More particularly, the present invention relates to an
oxo-nitrogenated iron complex and to its use in a catalytic system
for the (co)polymerization of conjugated dienes.
[0003] The present invention also relates to a catalytic system for
the (co)polymerization of conjugated dienes comprising said
oxo-nitrogenated iron complex.
[0004] Furthermore, the present invention relates to a
(co)polymerization process of conjugated dienes, in particular, to
a process for the polymerization of 1-3-butadiene or isoprene,
characterized in that it uses said catalytic system.
[0005] It is known that the stereospecific (co)polymerization of
conjugated dienes is a very important process in the chemical
industry in order to obtain products that are among the most widely
used rubbers.
[0006] It is also known that among the different polymers that can
be obtained from the stereospecific polymerization of 1,3-butadiene
(i.e. 1,4-cis, 1,4-trans, 1,2 syndiotactic, 1,2 isotactic, 1,2
atactic, mixed structure 1,4-cis/1,2 having a variable 1,2 unit
content), only 1,4-cis polybutadiene and 1,2 syndiotactic
polybutadiene are industrially produced and commercially available.
Further details on said polymers can be found, for example, in:
Takeuchi Y. et al., "New Industrial Polymers", "American Chemical
Society Symposium Series" (1974), Vol. 4, pg. 15-25; Halasa A. F.
et al., "Kirk-Othmer Encyclopedia of Chemical Technology" (1989),
4.sup.th Ed., Kroschwitz J. I. Ed., John Wiley and Sons, New York,
Vol. 8, pg. 1031-1045; Tate D. et al., "Encyclopedia of Polymer
Science and Engineering (1989), 2.sup.nd Ed., Mark H. F. Ed., John
Wiley and Sons, New York, Vol. 2, pg. 537-590; Kerns M. et al.,
"Butadiene Polymers", in "Encyclopedia of Polymer Science and
Technology" (2003), Mark H. F. Ed., Wiley, Vol. 5, pg. 317-356.
[0007] Generally, 1,4-cis polybutadiene is prepared through
polymerization processes that use different catalytic systems
comprising catalysts based on titanium (Ti), cobalt (Co), nickel
(Ni), neodymium (Nd). Catalytic systems comprising cobalt based
catalysts have high catalytic activity and stereospecificity and
can be considered the most versatile of those mentioned above
since, when by changing their formulation, they are able to provide
all the possible stereoisomers of polybutadiene mentioned above, as
described, for example, in: Porri L. et al., "Comprehensive Polymer
Science" (1989), Eastmond G. C. et al. Eds., Pergamon Press,
Oxford, UK, Vol. 4, Part II, pg. 53-108; Thiele S. K. H. et al.,
"Macromolecular Science. Part C: Polymer Reviews" (2003), C43, pg.
581-628; Osakada, K. et al., "Advanced Polymer Science" (2004),
Vol. 171, pg. 137-194; Friebe L. et al., "Advanced Polymer Science"
(2006), Vol. 204, pg. 1-154.
[0008] Iron (Fe) based catalysts have also been studied which are
useful in the (co)polymerization of conjugated dienes. One of the
first studies in literature on catalytic systems comprising iron
(Fe) based catalysts concerned the (co)polymerization of
1,3-butadiene and isoprene with catalytic systems comprising iron
acetylacetonate [Fe(acac).sub.3], tri-iso-butyl-aluminum (TIBA) and
1,10-phenanthroline (phen) as described, for example, in Zhang Z.
Y. et al., "Journal of Molecular Catalysis" (1982), Vol. 17, Issue
1, pg. 65-76. Said catalytic system is able to provide a binary
polybutadiene with a mixed 1,4-cis/1,2 structure having an equal
content of 1,4-cis and 1,2 units. The active species in said
catalytic system is likely to be constituted, as suggested by the
authors, by an iron (II) complex [Fe(II)] formed by the reduction
of iron acetylacetonate [Fe(acac)] through reaction with
tri-iso-butyl-aluminum (TIBA), said iron (II) complex [Fe(II)]
containing 1,10-phenanthroline (phen) as a ligand.
[0009] U.S. Pat. No. 6,160,063 describes a catalytic system
obtained by combination or by reaction of: a compound containing
iron (e.g., iron carboxylate, iron .beta.-diketonate, iron
alkoxide, iron arylalkoxide); an organic compound of magnesium; and
a cyclic hydrogen phosphite. The aforementioned catalytic system is
particularly useful for the polymerization of 1,3-butadiene for
providing binary polybutadiene with a mixed 1,4-cis/1,2
structure.
[0010] U.S. Pat. No. 6,180,734 describes a catalytic system
obtained by combination or by reaction of: a compound containing
iron (e.g., iron carboxylate, iron 1-diketonate, iron alkoxide,
iron arylalkoxide); cyclic hydrogen phosphite; and an organic
compound of aluminum. The aforementioned catalytic system is
particularly useful for the polymerization of 1,3-butadiene for
providing 1,2 syndiotactic polybutadiene.
[0011] U.S. Pat. No. 6,211,313 describes a catalytic system
obtained by combination or by reaction of: a compound containing
iron (e.g., iron carboxylate, iron .beta.-diketonate, iron
alkoxide, iron arylalkoxide); cyclic hydrogen phosphite; and an
aluminoxane. The aforementioned catalytic system is particularly
useful for the polymerization of 1,3-butadiene for providing 1,2
syndiotactic polybutadiene.
[0012] U.S. Pat. No. 6,277,779 describes a catalytic system
obtained by combination or by reaction of: a compound containing
iron (e.g., iron carboxylate, iron 9R-diketonate, iron alkoxide,
iron arylalkoxide); a dihydrocarbyl hydrogen phosphite; and an
organic compound of aluminum. The aforementioned catalytic system
is particularly useful for the polymerization of 1,3-butadiene for
providing 1,2 syndiotactic polybutadiene having a melting point
that can vary between 100.degree. C. and 200.degree. C., according
to the components and the ratios between the different components
present in said catalytic system.
[0013] U.S. Pat. Nos. 6,284,702 and 6,388,030 describe a catalytic
system obtained by combination or by reaction of: a compound
containing iron (e.g., iron carboxylate, iron .beta. diketonate,
iron alkoxide, iron arylalkoxide); an organic compound of
magnesium; and a dihydrocarbyl hydrogen phosphite. The
aforementioned catalytic system is particularly useful for the
polymerization of 1,3-butadiene for providing 1,2 syndiotactic
polybutadiene having a melting point that can vary between
100.degree. C. and 190.degree. C., according to the components and
the ratios between the different components present in said
catalytic system.
[0014] Catalytic systems comprising, for example, iron diethyl
bis(2,2'-bipyridine) [(Bipy).sub.2FeEt.sub.2] and methylaluminoxane
(MAO), or comprising various iron dichloride (FeCl.sub.2) complexes
with bidentate aromatic amines (e.g.,
N,N,N',N'-tetramethylethylenediamine (tmeda),
N,N'-dimethylethylenediamine (dmeda), 2,2'-bipyridine (bipy),
1,10-phenanthroline (phen), and compounds of aluminum [e.g.,
aluminum alkyls (AlR.sub.3 wherein R is ethyl, iso-butyl),
methylaluminoxane (MAO)], are extremely active in the
(co)polymerization of conjugated dienes, as described, for example,
in international patent application WO 02/102861; or in Bazzini C.
et al., "Macromolecular Rapid Communications" (2002), Vol. 23(15),
pg. 922-927; Bazzini C. et al., "Polymer Communication" (2004),
Vol. 45, pg. 2871-2875; Ricci G. et al., "Journal of Molecular
Catalysis A: Chemical" (2003), Vol. 204-205, pg. 287-293; Ricci G.
et al., "Coordination Chemistry Reviews" (2010), Vol. 254, Issues
5-6, pg. 661-676. Such catalytic systems are able to provide
polybutadienes with a prevalently 1,2 structure; in particular, the
polybutadienes obtained at low temperatures have an approximately
90% 1,2 structure and a 50% syndiotactic pentade structure, and the
1,2 unit and syndiotactic pentade contents are reduced as the
polymerization temperature increases. Furthermore, the
polybutadienes obtained with the aforementioned catalytic systems
have a very high weight-average molecular weight (M.sub.w) and a
rather restricted polydispersion index (PDI) corresponding to the
ratio M.sub.w/M.sub.n (M.sub.n=number-average molecular weight)
e.g., ranging from 1 to 2, indicating a "pseudo-living" nature of
said catalytic systems which are indicated as "single site". A
significant effect of the nature of the amine ligand on the
catalytic activity of said catalytic systems has also been
observed: in particular, the catalytic activity is reduced as the
steric size of the ligand increases. Furthermore, the type of
aluminum compound can also affect the catalytic activity: in fact,
it has been observed that when methylaluminoxane (MAO) is used,
there is an increase in the 1,2 unit content under the same
polymerization conditions. Furthermore, the aforementioned
catalytic systems were shown to be extremely active and selective
not only in the polymerization of 1,3-butadiene but also in the
(co)polymerization of other conjugated dienes such as, for example,
isoprene, 2,3-dimethyl-1,3-butadiene, 3-methyl-1,3-pentadiene,
providing (co)polymers with different structures such as, for
example, syndiotactic 3,4 polyisoprene, 1,4-cis
poly(2,3-dimethyl-1,3-butadiene), syndiotactic
E-1,2-poly(3-methyl-1,3-pentadiene).
[0015] Catalytic systems comprising iron ter-pyridine complexes
[e.g., FeCl.sub.3(ter-pyridine)], in combination with appropriate
alkylating agents, are useful in the stereospecific polymerization
of conjugated dienes: said catalytic systems show discrete
catalytic activity and are able to provide polybutadienes with a
1,4-trans structure as described, for example, in Nakayama Y. et
al., "Macromolecules" (2003), Vol. 36(21), pg. 7953-7958.
[0016] Catalytic systems obtained through the combination of iron
(III) carboxylates (e.g., iron (Ill) 2-ethylhexanoate
[Fe(2-EHA).sub.3]Fe(III) with aluminum tri-iso-butyl
(Al.sup.IBu.sub.3) in hexane, in the presence of phosphates (e.g.,
triethylphosphate) are able to polymerize 1,3-butadiene to
polybutadiene with a prevalently 1,2 structure and with a high
degree of syndiotacticity as described, for example, in Gong D. et
al., "Polymer" (2009), Vol. 50, pg. 5980-5986.
[0017] Catalytic systems comprising complexes obtained from iron
trichloride (FeCl.sub.3) or from iron dichloride tetrahydrate
(FeCl.sub.2.4H.sub.2O) with substituted
2,6-bis[1-(iminophenyl)ethyl]pyridine or 2,6-bis(imino)pyridine, in
the presence of methylaluminoxane (MAO), are able to provide high
1,4-trans structure (>90%), or 1,4-cis/1,4-trans mixed structure
polybutadienes, as a function of the catalytic system used as
described, for example, in Gong D. et al., "Polymer" (2009), Vol.
50, pg. 6259-6264; Gong D. et al., "Inorganic Chimica Acta" (2011),
Vol. 373, Issue 1, pg. 47-53.
[0018] Catalytic systems comprising complexes obtained from iron
trichloride (FeCl.sub.3) or from iron dichloride tetrahydrate
(FeCl.sub.2.4H.sub.2O) with substituted
2,6-bis[1-(2-benzimidazolyl)]pyridine or 2,6-bis(pyrazol)pyridine,
in the presence of modified methylaluminoxane (MMAO) or
diethylaluminum chloride (AlEt.sub.2Cl), are able to provide
polybutadienes with a different structure, i.e. 1,4-trans or
1,4-cis, as a function of the catalytic system used as described,
for example, in Gong D. et al., "Journal of Organometallic
Chemistry" (2012), Vol. 702, pg. 10-18.
[0019] Bis-imine complexes of iron (II) [Fe(II] with pincer ligands
in combination with aluminum alkyl [for example, tri-methylaluminum
(AlMe.sub.3) are able to provide polybutadienes with an essentially
1,4-cis structure (.gtoreq.70%) as described, for example, in Zhang
J. et al., "Dalton Transactions" (2012), Vol. 41, pg.
9639-9645.
[0020] Catalytic systems comprising bis-imine-pyridine complexes of
iron, aluminum alkyls (e.g., AlR.sub.3 wherein R is ethyl,
iso-butyl), and boron salts, are able to polymerize isoprene to
polyisoprene with a high 1,4-trans structure as described, for
example, in Raynaud J. et al., "Angewandte Chemie International
Edition" (2012), Vol. 51, pg. 11805-11808. Catalytic systems
comprising iron (II) complexes with substituted
2-pyrazolyl-1,10-phenanthroline and aluminum alkyls (e.g.,
AlR.sub.3 wherein R is ethyl, iso-butyl, octyl), are characterized
by a high and selective catalytic level and are able to provide
polybutadienes with a high 1,4-trans structure as described, for
example, in Wang B. et al., "Polymer" (2013), Vol. 54, pg.
5174-5181.
[0021] Catalytic systems comprising iron (II) complexes with
2-(N-arylcarboxyimidoylchloride)quinoline and aluminum alkyls
[e.g., AlR.sub.3 wherein R is ethyl, iso-butyl; or
methylaluminoxane (MAO)], are characterized by low catalytic
activity and are able to provide polybutadienes with a high 1,4-cis
structure as described, for example, in Liu H. et al., "Journal of
Molecular Catalysis A: Chemical" (2014), Vol. 391, pg. 25-35.
[0022] Catalytic systems comprising iron (II) complexes with
2,6-bis(dimethyl-2-oxazoline-2-yl)pyridine and aluminum alkyls
[e.g., AlR.sub.3 wherein R is ethyl, iso-butyl; or
methylaluminoxane (MAO)], are able to provide polybutadienes with a
mixed 1,4-cis/1,4-trans structure as described, for example, in
Gong D. et al., "Journal of Molecular Catalysis A: Chemical"
(2015), Vol. 406, pg. 78-84.
[0023] Finally, polybutadienes with "soft/hard" stereoblocks, with
a mixed 1,4-cis/1,2 structure were obtained using the catalytic
system 2-ethylhexanoate of iron/tri-iso-butylaluminum/diethyl
phosphate [Fe(2-EHA).sub.3/Al.sup.IBu).sub.3/DEP], appropriately
varying the aluminum/iron (Al/Fe) ratio as described, for example,
in Zheng W. et al., "Journal of Polymer Science Part A: Polymer
Chemistry" (2015), Vol. 53, Issue 10, pg. 1182-1188. Since
(co)polymers of conjugated dienes, in particular polybutadiene and
polyisoprene, can be advantageously used for producing tires, in
particular for tire treads, as well as in the footwear industry
(e.g., for producing soles for shoes), the study of new catalytic
systems able to provide said (co)polymers is still of great
interest.
[0024] The Applicant has considered the problem of finding a new
oxo-nitrogenated iron complex to be used in a catalytic system able
to provide (co)polymers of conjugated dienes, such as, for example,
linear or branched polybutadiene or linear or branched
polyisoprene, with a mixed structure, in particular, polybutadiene
with a prevalent 1,4-cis and 1,2 unit content (i.e. having a
content of 1,4-cis and 1,2 units .gtoreq.90%, preferably equal to
100%), and polyisoprene with a prevalent content of 1,4-cis and 3,4
units (i.e. having a content of 1,4-cis and 3,4 units .gtoreq.90%,
preferably equal to 100%).
[0025] The Applicant has now found a new oxo-nitrogenated iron
complex having general formula (I) or (II) below defined, able to
provide (co)polymers of conjugated dienes, such as, for example,
linear or branched polybutadiene or polyisoprene, with a mixed
structure, in particular, polybutadiene with a prevalent 1,4-cis
and 1,2 unit content (i.e. having a content of 1,4-cis and 1,2
units 90%, preferably equal to 100%), and polyisoprene with a
prevalent content of 1,4-cis and 3,4 units (i.e. having a content
of 1,4-cis and 3,4 units 90%, preferably equal to 100%).
[0026] Therefore, the subject matter of the present invention is an
oxo-nitrogenated iron complex having general formula (I) or
(Ill):
##STR00002##
wherein: [0027] R.sub.1 and R.sub.2, identical or different,
represent a hydrogen atom; or are selected from linear or branched,
optionally halogenated C.sub.1-C.sub.20, preferably
C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl
groups, optionally substituted aryl groups; [0028] R.sub.3,
identical or different, represent a hydrogen atom; or are selected
from linear or branched, optionally halogenated C.sub.1-C.sub.20,
preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted
cycloalkyl groups, optionally substituted aryl groups; [0029]
X.sub.1 and X.sub.2, identical or different, represent a halogen
atom such as, for example, chlorine, bromine, iodine; or are
selected from linear or branched C.sub.1-C.sub.20, preferably
C.sub.1-C.sub.15, alkyl groups, --OCOR.sub.4 groups or --OR.sub.4
groups wherein R.sub.4 is selected from linear or branched
C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups.
[0030] For the purpose of the present description and of the
following claims, the definitions of the numeric ranges always
include the extremes unless otherwise specified.
[0031] For the purpose of the present description and of the
following claims, the term "comprising" also includes the terms
"which essentially consists of" or "which consists of". For the
purpose of the present description and of the following claims, the
term "C.sub.1-C.sub.20 alkyl groups" means alkyl groups having from
1 to 20 carbon atoms, linear or branched. Specific examples of
C.sub.1-C.sub.20 alkyl groups are: methyl, ethyl, n-propyl,
iso-propyl, n-butyl, s-butyl, iso-butyl, tert-butyl, pentyl, hexyl,
heptyl, octyl, n-nonyl, n-decyl, 2-butyloctyl, 5-methylhexyl,
4-ethylhexyl, 2-ethylheptyl, 2-ethylhexyl.
[0032] For the purpose of the present description and of the
following claims, the term "optionally halogenated C.sub.1-C.sub.20
alkyl groups" means alkyl groups having from 1 to 20 carbon atoms,
linear or branched, saturated or unsaturated, wherein at least one
of the hydrogen atoms is substituted with a halogen atom such as,
for example, fluorine, chlorine, bromine, preferably fluorine,
chlorine. Specific examples of C.sub.1-C.sub.20 alkyl groups
optionally containing halogenated are: fluoromethyl,
difluoromethyl, trifluoromethyl, trichloromethyl,
2,2,2-trifluoroethyl, 2,2,2-trichloroethyl,
2,2,3,3-tetrafluoropropyl, 2,2,3,3,3-pentafluoropropyl,
perfluoropentyl, perfluoroctyl, perfluorodecyl.
[0033] For the purpose of the present description and of the
following claims, the term "cycloalkyl groups" means cycloalkyl
groups having from 3 to 30 carbon atoms. Said cycloalkyl groups can
be optionally substituted with one or more groups, identical or
different, selected from: halogen atoms; hydroxyl groups,
C.sub.1-C.sub.12 alkyl groups; C.sub.1-C.sub.12 alkoxy groups;
cyano groups; amino groups; nitro groups. Specific examples of
cycloalkyl groups are: cyclopropyl, 2,2-difluorocyclopropyl,
cyclobutyl, cyclopentyl, cyclohexyl, hexamethylcyclohexyl,
pentamethlylcyclopentyl, 2-cyclooctylethyl, methylcyclohexyl,
methoxycyclohexyl, fluorocyclohexyl, phenylcyclohexyl.
[0034] For the purpose of the present description and of the
following claims, the term "aryl groups" means carbocyclic aromatic
groups. Said carbocyclic aromatic groups can be optionally
substituted with one or more groups, identical or different,
selected from: halogen atoms such as, for example, fluorine,
chlorine, bromine; hydroxyl groups, C.sub.1-C.sub.12 alkyl groups;
C.sub.1-C.sub.12 alkoxy groups; cyano groups; amino groups; nitro
groups. Specific examples of aryl groups are: phenyl,
2-methylphenyl, 4-methylphenyl, 2,4,6-trimethylphenyl,
2,6-di-iso-propylphenyl, methoxyphenyl, hydroxyphenyl,
phenyloxyphenyl, fluorophenyl, pentafluorophenyl, chlorophenyl,
bromophenyl, nitrophenyl, dimethylaminophenyl, naphthyl,
phenylnaphthyl, phenanthrene, anthracene.
[0035] In accordance with a preferred embodiment of the present
invention, in said oxo-nitrogenated iron complex having general
formula (I) or (II): [0036] R.sub.1 and R.sub.2, mutually
identical, are selected from linear or branched C.sub.1-C.sub.20
alkyl groups, preferably are a methyl group; [0037] R.sub.3,
mutually identical, are selected from aryl groups optionally
substituted with linear or branched C.sub.1-C.sub.20 alkyl groups,
preferably with one or more methyl, ethyl, tert-butyl or iso-propyl
groups, preferably are a phenyl group, 2-methylphenyl,
4-methylphenyl, 2,4,6-trimethylphenyl, 2,6-di-iso-propylphenyl;
[0038] X.sub.1 and X.sub.2, mutually identical, are a halogen atom
such as, for example, chlorine, bromine, iodine, preferably
chlorine.
[0039] The oxo-nitrogenated iron complex having general formula (I)
or (II) can be considered, in accordance with the present
invention, under any physical form such as, for example, the
isolated and purified solid form, the form solvated with an
appropriate solvent, or the one supported on suitable organic or
inorganic solids, preferably having a granular or powdered physical
form.
[0040] The oxo-nitrogenated iron complex having general formula (I)
or (II) is prepared starting from ligands known in the prior
art.
[0041] Specific examples of ligands useful for the purpose of the
present invention are those having the following formulae
(L1)-(L5):
##STR00003##
[0042] Said ligands having formulae (L1)-(L5), can be prepared
through processes known in the prior art. For example, said ligands
having formulae (L1)-(L5) can be prepared through condensation
reactions between primary amines and diketones as described, for
example, in international patent application WO 2013/037911 in the
name of the Applicant; or by: Parks J. E. and Holm R. H. in
"Inorganic Chemistry" (1968), Vol 7(7), pg. 1408-1416; Roberts E.
and Turner E. E. in "Journal of Chemical Society" (1927), pg.
1832-1857; Dudek G. O. and Holm R. H. in "Journal of the American
Chemical Society" (1961), Vol. 83, Issue 9, pg. 2099-2104. More
details on the process for the preparation of said ligands having
formulae (L1)-(L5) can be found in the following examples.
[0043] The oxo-nitrogenated iron complex having general formula (I)
or (II) can be prepared according to processes known in the prior
art. For example, said oxo-nitrogenated iron complex can be
prepared by reaction between iron compounds having general formula
Fe(X).sub.2 or Fe(X).sub.3 wherein X is a halogen atom such as, for
example, chlorine, bromine, iodine, preferably chlorine, as it is
or complexed with ethers [e.g., diethylether, tetrahydrofuran
(THF), dimethoxyethane], or with water, with the ligands having
formulae (L1)-(L5) reported above, in molar ratio ligand (L)/iron
(Fe) ranging from 1 to 2 operating, preferably, in the presence of
at least one solvent which can be selected, for example, from:
chlorinated solvents (e.g., methylene chloride), ether solvents,
[e.g., tetrahydrofuran (THF)], alcoholic solvents (e.g., butanol),
hydrocarbon solvents (e.g., hexane), or mixtures thereof, at
ambient temperature or higher. In the case of an oxo-nitrogenated
iron complex having general formula (I), said ligands having
formulae (L1)-(L5), prior to the reaction with the aforementioned
iron compounds having general formula Fe(X).sub.2 or Fe(X).sub.3
wherein X has the meanings mentioned above, can be made to react
with a solution of an alkyllithium (e.g., n-butyllithium) in a
hydrocarbon solvent (e.g., hexane). The oxo-nitrogenated iron
complex thus obtained can be subsequently recovered through known
methods such as, evaporation of the solvent (e.g., under vacuum),
followed by solubilization in an appropriate solvent, subsequent
filtration (e.g., on Celite.RTM.) followed by drying (e.g., under
vacuum). More details on the process for the preparation of said
oxo-nitrogenated iron complex having general formula (I) or (II)
can be found in the following examples.
[0044] For the purpose of the present description and of the
following claims the expression "ambient temperature" means a
temperature ranging from 20.degree. C. to 25.degree. C.
[0045] As mentioned above, the present invention also relates to a
catalytic system for the (co)polymerization of conjugated dienes
comprising said oxo-nitrogenated iron complex having general
formula (I) or (II).
[0046] Therefore, the present invention also relates to a catalytic
system for the (co)polymerization of conjugated dienes comprising:
[0047] (a) at least one oxo-nitrogenated iron complex having
general formula (I) or (II); [0048] (b) at least one co-catalyst
selected from organic compounds of an element M' different from
carbon, said element M' being selected from elements belonging to
groups 2, 12, 13, or 14 of the Periodic Table of the Elements,
preferably from: boron, aluminum, zinc, magnesium, gallium, tin,
more preferably aluminum, boron.
[0049] In general, the formation of the catalytic system comprising
the oxo-nitrogenated iron complex having general formula (I) or
(II) and the co-catalyst (b), is preferably performed in an inert
liquid medium, more preferably in a hydrocarbon solvent. The choice
of the oxo-nitrogenated iron complex having general formula (I) or
(II) and of the co-catalyst (b), as well as the particular
methodology used, can vary according to the molecular structures
and to the desired result, according to what is similarly reported
in relevant literature accessible to an expert skilled in the art
for other transition metal complexes with imine ligands, as
reported, for example, by L. K. Johnson et al., in "Journal of the
American Chemical Society" (1995), Vol. 117, pg. 6414-6415, and by
G. van Koten et al., in "Advances in Organometallic Chemistry"
(1982), Vol. 21, pg. 151-239.
[0050] In accordance with a further preferred embodiment of the
present invention, said co-catalyst (b) can be selected from
(b.sub.1) aluminum alkyls having general formula (III):
Al(X').sub.n(R.sub.5).sub.3-n (111)
wherein X' represents a halogen atom such as, for example,
chlorine, bromine, iodine, fluorine; R.sub.5 is selected from
linear or branched C.sub.1-C.sub.20 alkyl groups, cycloalkyl
groups, aryl groups, said groups being optionally substituted with
one or more atoms of silicon or germanium; and n is an integer
ranging from 0 to 2.
[0051] In accordance with a further preferred embodiment of the
present invention, said co-catalyst (b) can be selected from
(b.sub.2) organo-oxygenated compounds of an element M' different
from carbon belonging to groups 13 or 14 of the Periodic Table of
the Elements, preferably organo-oxygenated compounds of aluminum,
gallium, tin. Said organo-oxygenated compounds (b.sub.2) can be
defined as organic compounds of M', wherein the latter is bonded to
at least one oxygen atom and to at least one organic group
comprising an alkyl group having from 1 to 6 carbon atoms,
preferably methyl.
[0052] In accordance with a further preferred embodiment of the
present invention, said co-catalyst (b) can be selected from
(b.sub.3) compounds or mixtures of organometallic compounds of an
element M' different from carbon able to react with the
oxo-nitrogenated iron complex having general formula (I) or (II) by
extracting from it a .sigma.-linked substituent X.sub.1 or X.sub.2,
to form on the one hand at least one neutral compound and, on the
other hand, an ionic compound consisting of a cation containing the
metal (Fe) coordinated by the ligand, and a non-coordinating
organic anion containing the metal M', whose negative charge is
delocalized on a multicentric structure.
[0053] It is to be noted that for the purpose of the present
invention and of the following claims, the term "Periodic Table of
the Elements" refers to the "IUPAC Periodic Table of the Elements",
version dated 1 Jun. 2012, available on the following website:
www.iupac.org/fileadmin/user upload/news/IUPAC Periodic
Table-1Jun12.pdf.
[0054] Specific examples of aluminum alkyls having general formula
(III) particularly useful for the purpose of the present invention
are: tri-methyl-aluminum, tri-(2,3,3-tri-methyl-butyl)-aluminum,
tri-(2,3-di-methyl-hexyl)-aluminum,
tri-(2,3-di-methyl-butyl)-aluminum,
tri-(2,3-di-methyl-pentyl)-aluminum,
tri-(2,3-di-methyl-heptyl)-aluminum,
tri-(2-methyl-3-ethyl-pentyl)-aluminum,
tri-(2-methyl-3-ethyl-hexyl)-aluminum,
tri-(2-methyl-3-ethyl-heptyl)-aluminum,
tri-(2-methyl-3-propyl-hexyl)-aluminum, tri-ethyl-aluminum,
tri-(2-ethyl-3-methyl-butyl)-aluminum,
tri-(2-ethyl-3-methyl-pentyl)-aluminum,
tri-(2,3-di-ethyl-pentyl-aluminum), tri-n-propyl-aluminum,
tri-iso-propyl-aluminum, tri-(2-propyl-3-methyl-butyl)-aluminum,
tri-(2-iso-propyl-3-methyl-butyl)-aluminum, tri-n-butyl-aluminum,
tri-iso-butyl-aluminum (TIBA), tri-tert-butyl-aluminum,
tri-(2-iso-butyl-3-methyl-pentyl)-aluminum,
tri-(2,3,3-tri-methyl-pentyl)-aluminum,
tri-(2,3,3-tri-methyl-hexyl)-aluminum,
tri-(2-ethyl-3,3-di-methyl-butyl)-aluminum,
tri-(2-ethyl-3,3-di-methyl-pentyl)-aluminum,
tri-(2-iso-propyl-3,3-dimethyl-butyl)-aluminum,
tri-(2-tri-methylsilyl-propyl)-aluminum,
tri-2-methyl-3-phenyl-butyl)-aluminum,
tri-(2-ethyl-3-phenyl-butyl)-aluminum,
tri-(2,3-di-methyl-3-phenyl-butyl)-aluminum,
tri-(2-phenyl-propyl)-aluminum,
tri-[2-(4-fluoro-phenyl)-propyl]-aluminum,
tri-[2-(4-chloro-phenyl)-propyl]-aluminum,
tri-[2-(3-iso-propyl-phenyl-tri-(2-phenyl-butyl)-aluminum,
tri-(3-methyl-2-phenyl-butyl)-aluminum,
tri-(2-phenyl-pentyl)-aluminum,
tri-[2-(penta-fluoro-phenyl)-propyl]-aluminum,
tri-(2,2-diphenyl-ethyl]-aluminum,
tri-(2-phenyl-methyl-propyl]-aluminum, tri-pentyl-aluminum,
tri-hexyl-aluminum, tri-cyclohexyl-aluminum, tri-octyl-aluminum,
di-ethyl-aluminum hydride, di-n-propyl-aluminum hydride,
di-n-butyl-aluminum hydride, di-iso-butyl-aluminum hydride (DIBAH),
di-hexyl-aluminum hydride, di-iso-hexyl-aluminum hydride,
di-octyl-aluminum hydride, di-iso-octyl-aluminum hydride,
ethyl-aluminum di-hydride, n-propyl-aluminum di-hydride,
iso-butyl-aluminum di-hydride, di-ethyl-aluminum chloride (DEAC),
mono-ethyl-aluminum dichloride (EADC), di-methyl-aluminum chloride,
di-iso-butyl-aluminum chloride, iso-butyl-aluminum dichloride,
ethyl-aluminum-sesquichloride (EASC), as well as the corresponding
compounds wherein one of the hydrocarbon substituents is
substituted by a hydrogen atom and those wherein one or two of the
hydrocarbon substituents are substituted with an iso-butyl group.
Di-ethyl-aluminum chloride (DEAC), mono-ethyl-aluminum dichloride
(EADC), ethylaluminum-sesquichloride (EASC), are particularly
preferred.
[0055] Preferably, when used for the formation of a catalytic
(co)polymerization system in accordance with the present invention,
the aluminum alkyls having general formula (III) can be placed in
contact with an oxo-nitrogenated iron complex having general
formula (i) or (II), in proportions such that the molar ratio
between the aluminum contained in the aluminum alkyls having
general formula (III) and the iron contained in the
oxo-nitrogenated iron complex having general formula (I) or (II)
can be ranging from 5 to 5000, preferably ranging from 10 to 1000.
The sequence with which the oxo-nitrogenated iron complex having
general formula (I) or (II) and the aluminum alkyl having general
formula (III) are placed in contact with each other is not
particularly critical.
[0056] Further details on aluminum alkyls having general formula
(III) can be found in international patent application WO
20111061151.
[0057] In accordance with a particularly preferred embodiment, said
organo-oxygenated compounds (b.sub.2) can be selected from the
aluminoxanes having general formula (IV):
(R.sub.6).sub.2--Al--O--[--Al(R.sub.7)--O--].sub.p--Al--(R.sub.8).sub.2
(IV)
wherein R.sub.9, R.sub.7 and R.sub.8, identical or different,
represent a hydrogen atom, a halogen atom such as, for example,
chlorine, bromine, iodine, fluorine; or are selected from
C.sub.1-C.sub.20 alkyl groups, linear or branched, cycloalkyl
groups, aryl groups, said groups being optionally substituted with
one or more atoms of silicon or germanium; and p is an integer
ranging from 0 to 1000.
[0058] As is known, aluminoxanes are compounds containing Al--O--Al
bonds, with a variable O/Al ratio, obtainable according to
processes known in the prior art such as, for example, by reaction,
in controlled conditions, of an aluminum alkyl, or of an aluminum
alkyl halogenide, with water, or with other compounds containing
predetermined quantities of available water such as, for example,
in the case of the reaction of aluminum trimethyl with aluminum
sulfate hexahydrate, copper sulfate pentahydrate, or iron sulfate
pentahydrate.
[0059] Said aluminoxanes and, in particular, methylaluminoxane
(MAO), are compounds that can be obtained through known
organometallic chemical processes such as, for example, by adding
trimethyl aluminum to a suspension in aluminum sulfate hexahydrate.
Preferably, when used for the formation of a catalytic
(co)polymerization system in accordance with the present invention,
the aluminoxanes having general formula (IV) can be placed in
contact with an oxo-nitrogenated iron complex having general
formula (I) or (II), in proportions such that the molar ratio
between the aluminum (Al) contained in the aluminoxane having
general formula (IV) and the iron contained in the oxo-nitrogenated
iron complex having general formula (I) or (II) is ranging from 10
to 10000, preferably ranging from 100 to 5000. The sequence with
which the oxo-nitrogenated iron complex having general formula (I)
or (II) and the aluminoxane having general formula (IV) are placed
in contact with each other is not particularly critical.
[0060] As well as the aforementioned preferred aluminoxanes having
general formula (IV), the definition of the compound (b.sub.2) in
accordance with the present invention also includes galloxanes
wherein, in the general formula (IV), gallium is contained in the
place of aluminum and stannoxanes wherein, in the general formula
(IV), tin is contained in the place of aluminum, whose use as
co-catalysts for the polymerization of olefins in the presence of
metallocene complexes is known. Further details in relation to said
galloxanes and stannoxanes can be found, for example, in the U.S.
Pat. Nos. 5,128,295 and 5,258,475.
[0061] Specific examples of aluminoxanes having general formula
(IV) particularly useful for the purpose of the present invention
are: methylaluminoxane (MAO), ethyl-aluminoxane,
n-butyl-aluminoxane, tetra-iso-butyl-aluminoxane (TIBAO),
tert-butyl-aluminoxane, tetra-(2,4,4-tri-methyl-pentyl)-aluminoxane
(TIOAO), tetra-(2,3-di-methyl-butyl)-aluminoxane (TDMBAO),
tetra-(2,3,3-tri-methyl-butyl)-aluminoxane (TTMBAO).
Methylaluminoxane (MAO) is particularly preferred.
[0062] Further details on aluminoxanes having general formula (IV)
can be found in international patent application WO
2011/061151.
[0063] In accordance with a preferred embodiment of the present
invention, said compounds or mixtures of compounds (b.sub.3) can be
selected from organic compounds of aluminum and especially of
boron, such as, for example, those represented by the following
general formulae:
[(R.sub.C).sub.WH.sub.4-W].[B(R.sub.D).sub.4]--; B(R.sub.D).sub.3;
Al(R.sub.D).sub.3; B(R.sub.D).sub.3Pyr;
[Ph.sub.3C]+.[B(R.sub.D).sub.4]--;
[(R.sub.C).sub.3PyrH]+.[B(R.sub.D).sub.4]--;
[Li]+.[B(R.sub.D).sub.4]--; [Li]+.[Al(R.sub.D).sub.4]--
wherein w is an integer ranging from 0 to 3, each R.sub.C group
independently represents an alkyl group or an aryl group having
from 1 to 10 carbon atoms and each RD group independently
represents an aryl group partially or totally, preferably totally,
fluorinated, having from 6 to 20 carbon atoms, Pyr is a pyrrole
radical, optionally substituted.
[0064] Preferably, when used for the formation of a catalytic
(co)polymerization system in accordance with the present invention,
the compounds or mixtures of compounds (b.sub.3) can be placed in
contact with an oxo-nitrogenated iron complex having general
formula (I) or (II), in proportions such that the molar ratio
between the metal (M') contained in the compounds or mixtures of
compounds (b.sub.3) and the iron contained in the oxo-nitrogenated
iron complex having general formula (I) or (II) is ranging from 0.1
to 15, preferably ranging from 0.5 to 10, more preferably ranging
from 1 to 6. The sequence with which the oxo-nitrogenated iron
complex having general formula (I) or (II) and the compound or
mixture of compounds (b.sub.3) are placed in contact with each
other is not particularly critical. Said compounds or mixtures of
compounds (b.sub.3), especially in the case wherein X, and X.sub.2
in the oxo-nitrogenated iron complex having general formula (I) or
(II) are different from alkyl, must be used in combination with an
aluminoxane having general formula (IV) such as, for example,
methylaluminoxane (MAO), or, preferably, with an aluminum alkyl
having general formula (II), more preferably a trialkylaluminum
having from 1 to 8 carbon atoms in each alkyl residue, such as, for
example, tri-methyl-aluminum, tri-ethyl-aluminum,
tri-iso-butylaluminum (TIBA).
[0065] Examples of the methodologies generally used for the
formation of a catalytic (co)polymerization system in accordance
with the present invention, in the case of using compounds or
mixtures of compounds (b.sub.3), are qualitatively schematized in
the list reported below, which does not however limit the overall
scope of the present invention: [0066] (m.sub.1) contact of an
oxo-nitrogenated iron complex having general formula (I) or (II)
wherein at least one from X.sub.1 and X.sub.2 is an alkyl group,
with at least one compound or a mixture of compounds (b.sub.3)
whose cation is able to react with said alkyl group to form a
neutral compound, and whose anion is voluminous, non-coordinating
and able to delocalize the negative charge; [0067] (m.sub.2)
reaction of an oxo-nitrogenated iron complex having general formula
(I) or (II) with at least one aluminum alkyl having general formula
(III), preferably a trialkylaluminum, used in excess molar ratio
from 10/1 to 300/1, followed by the reaction with a strong Lewis
acid, such as, for example, tris(pentafluorophenyl)boron [compound
(b.sub.3)], in almost stoichiometric quantities or in slight excess
with respect to the iron (Fe); [0068] (m.sub.3) contact and
reaction of an oxo-nitrogenated iron complex having general formula
(I) or (II) with an excess molar ratio from 10/1 to 1000/1,
preferably from 100/1 to 500/1 of at least a trialkylaluminum or an
alkyl aluminum halogenide that can be represented with the formula
AlR'''.sub.mZ.sub.3-m wherein R''' is a C.sub.1-C.sub.8 alkyl
group, linear or branched, or a mixture thereof, Z is a halogen,
preferably chlorine or bromine, and m is a decimal number ranging
from 1 to 3, followed by the addition to the composition thus
obtained of at least one compound or mixture of compounds (b.sub.3)
in quantities such that the ratio between said compound or mixture
of compounds (b.sub.3) or the aluminum of said compound or mixture
of compounds (b.sub.3) and the iron of the oxo-nitrogenated iron
complex having general formula (I) or (II) is ranging from 0.1 to
15, preferably from 1 to 6.
[0069] Examples of compounds or mixtures of compounds (b.sub.3)
able to produce an ionic catalytic system by reaction with an
oxo-nitrogenated iron complex having general formula (I) or (II)
according to the present invention are described, although with
reference to the formation of ionic metallocene complexes, in the
following publications, whose contents is incorporated herein for
reference purposes: [0070] W. Beck et al., "Chemical Reviews"
(1988), Vol. 88, pg. 1405-1421; [0071] S. H. Stares, "Chemical
Reviews" (1993), Vol. 93, pg. 927-942; [0072] european patent
applications EP 277 003, EP 495 375, EP 520 732, EP 427 697, EP 421
659, EP 418044; [0073] published international patent applications
WO 92/00333, WO 92/05208.
[0074] Specific examples of compounds or mixtures of compounds
(b.sub.3) particularly useful for the purpose of the present
invention are: tributylammonium-tetrakis-pentafluorophenyl-borate,
tributylammonium-tetrakis-pentafluorophenyl-aluminate,
tributylammonium-tetrakis-[(3,5-di-(trifluorophenyl)]-borate,
tributylammonium-tetrakis-(4-fluorophenyl)]-borate,
N,N-dimethylbenzylammonium-tetrakis-pentafluoro-phenyl-borate,
N,N-dimethyl-hexylammonium-tetrakis-pentafluorophenyl-borate, N,
N-dimethylanilinium-tetrakis-(pentafluorophenyl)-borate, N,
N-dimethylanilinium-tetrakis-(pentafluorophenyl)-aluminate,
di-(propyl)-ammonium-tetrakis-(pentafluorophenyl)-borate,
di-(cyclohexyl)-ammonium-tetrakis-(pentafluorophenyl)-borate,
tri-phenyl-carbenium-tetrakis-(pentafluorophenyl)-borate,
tri-phenylcarbenium-tetrakis-(penta-fluorophenyl)-aluminate,
tris(pentafluorophenyl)boron, tris(pentafluorophenyl)-aluminum, or
mixtures thereof. Tetrakis-pentafluorophenyl-borates are
preferred.
[0075] For the purpose of the present description and of the
following claims, the terms "mole" and "molar ratio" are used both
with reference to compounds consisting of molecules and with
reference to atoms and ions, omitting for the latter ones the terms
gram atom or atomic ratio, even if they are scientifically more
accurate.
[0076] For the purpose of the present invention, other additives or
components can potentially be added to the aforementioned catalytic
system so as to adapt it to satisfy specific practical
requirements. The catalytic systems thus obtained can therefore be
considered included within the scope of the present invention.
Additives and/or components that can be added in the preparation
and/or formulation of the catalytic system according to the present
invention are, for example: inert solvents, such as, for example,
aliphatic and/or aromatic hydrocarbons; aliphatic and/or aromatic
ethers; weakly coordinating additives (e.g., Lewis bases) selected,
for example, from non-polymerizable olefins; sterically hindered or
electronically poor ethers; halogenating agents such as, for
example, silicon halides, halogenated hydrocarbons, preferably
chlorinated; or mixtures thereof.
[0077] Said catalytic system can be prepared, as already reported
above, according to methods known in the prior art.
[0078] For example, said catalytic system can be prepared
separately (preformed) and subsequently introduced into the
(co)polymerization environment. On this point, said catalytic
system can be prepared by making at least one oxo-nitrogenated iron
complex (a) having general formula (I) or (II) react with at least
one co-catalyst (b), possibly in presence of other additives or
components selected from those cited above, in the presence of a
solvent such as, for example, toluene, heptane, at a temperature
ranging from 20.degree. C. to 60.degree. C., for a time ranging
from 10 seconds to 10 hours, preferably ranging from 30 seconds to
5 hours. Further details on the preparation of said catalytic
system can be found in the examples reported below.
[0079] Alternatively, said catalytic system can be prepared in
situ, i.e. directly in the (co)polymerization environment. On that
point, said catalytic system can be prepared by separately
introducing the oxo-nitrogenated iron complex (a) having general
formula (I) or (II), the co-catalyst (b) and the pre-selected
conjugated diene(s) to be (co)polymerized, operating at the
conditions wherein the (co)polymerization is performed.
[0080] For the purpose of the present invention, the aforementioned
catalytic systems can also be supported on inert solids, preferably
constituted by silicon and/or aluminum oxides, such as, for
example, silica, alumina or silico-aluminates. For supporting said
catalytic systems the known supporting techniques can be used,
generally comprising contact, in a suitable inert liquid medium,
between the support, optionally activated by heating to
temperatures over 200.degree. C., and one or both components (a)
and (b) of the catalytic system according to the present invention.
It is not necessary, for the purposes of the present invention, for
both components to be supported, since only the oxo-nitrogenated
iron complex (a) having general formula (I) or (II), or the
co-catalyst (b) can be present on the support surface. In the
latter case, the missing component on the surface is subsequently
placed in contact with the supported component when the active
catalyst is to be formed by polymerization.
[0081] The scope of the present invention also includes the
oxo-nitrogenated iron complex having general formula (I) or (II),
and the catalytic systems based thereon, which are supported on a
solid through the functionalization of the latter and the formation
of a covalent bond between the solid and the oxo-nitrogenated iron
complex having general formula (I) or (II).
[0082] Furthermore, the present invention relates to a
(co)polymerization process of conjugated dienes, characterized in
that it uses said catalytic system.
[0083] The quantity of oxo-nitrogenated iron complex (a) having
general formula (I) or (II) and of co-catalyst (b) which can be
used in the (co)polymerization of conjugated dienes varies
according to the (co)polymerization process to be performed. Said
quantity is however such as to obtain a molar ratio between the
iron contained in the oxo-nitrogenated iron complex having general
formula (I) or (II) and the metal contained in the co-catalyst (b),
e.g., aluminum in the case wherein the co-catalyst (b) is selected
from the aluminum alkyls (b.sub.1) or from the aluminoxanes
(b.sub.2), boron in the case wherein the co-catalyst (b) is
selected from the compounds or mixtures of compounds (b.sub.3)
having general formula (IV), comprised between the values reported
above.
[0084] Specific examples of conjugated dienes that can be
(co)polymerized using the catalytic system in accordance with the
present invention are: 1,3-butadiene, 2-methyl-1,3-butadiene
(isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene,
1,3-hexadiene, cyclo-1,3-hexadiene. Preferred (co)polymerizable
conjugated dienes are 1,3-butadiene, isoprene. The aforementioned
(co)polymerizable conjugated dienes can be used alone, or in a
mixture of two or more dienes. In this latter case, i.e. using a
mixture of two or more dienes, a copolymer will be obtained.
[0085] In accordance with a particularly preferred embodiment, the
present invention relates to a polymerization process of
1,3-butadiene or isoprene, characterized in that it uses said
catalytic system.
[0086] Generally, said (co)polymerization can be performed in the
presence of a polymerization solvent, generally selected from inert
organic solvents, such as, for example: saturated aliphatic
hydrocarbons such as, for example, butane, pentane, hexane,
heptane, or mixtures thereof; saturated cyclo-aliphatic
hydrocarbons such as, for example, cyclopentane, cyclohexane, or
mixtures thereof; mono-olefins such as, for example, 1-butene,
2-butene, or mixtures thereof; aromatic hydrocarbons such as, for
example, benzene, toluene, xylene, or mixtures thereof; halogenated
hydrocarbons such as, for example, methylene chloride, chloroform,
carbon tetrachloride, trichloroethylene, perchloroethylene,
1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene, or
mixtures thereof. Preferably the (co)polymerization solvent is
selected from saturated alyphatic hydrocarbons.
[0087] Alternatively, said (co)polymerization can be performed
using as a (co)polymerization solvent the same conjugated diene(s)
that must be (co)polymerized, in accordance with the process known
as "bulk process".
[0088] Generally, the concentration of the conjugated diene to be
(co)polymerized in said (co)polymerization solvent is ranging from
5% by weight to 50% by weight, preferably ranging from 10% by
weight to 20% by weight, with respect to the total weight of the
conjugated diene mixture and inert organic solvent.
[0089] Generally, said (co)polymerization can be performed at a
temperature ranging from -70.degree. C. to +100.degree. C.,
preferably ranging from -20.degree. C. to +80.degree. C.
[0090] With regard to pressure, it is preferable to operate at the
pressure of the components of the mixture to be
(co)polymerized.
[0091] Said (co)polymerization can be performed both continuously
and batchwise.
[0092] As mentioned above, said process allows (co)polymers of
conjugated dienes to be obtained, such as, polybutadiene,
polyisoprene, in particular polybutadiene, linear or branched, with
a mixed structure, in particular, polybutadiene with a prevalent
1,4-cis and 1,2 unit content (i.e. having a content of 1,4-cis and
1,2 units 90%, preferably equal to 100%), and polyisoprene with a
prevalent content of 1,4-cis and 3,4 units (i.e. having a content
of 1,4-cis and 3,4 units .gtoreq.90%, preferably equal to
100%).
[0093] For the purpose of better understanding the present
invention and to put it into practice, below are some illustrative
and non-limiting examples thereof.
EXAMPLES
Reagents and Materials
[0094] The list below reports the reagents and materials used in
the following examples of the invention, any optional
pre-treatments thereof and their manufacturer: [0095] iron powder
(Fe) (Aldrich): purity 99%, used as it is; [0096] iron trichloride
(FeCl.sub.3) (Aldrich): purity 99.9%, used as it is; [0097] iron
dichloride (FeCl.sub.2) (Aldrich): purity 97%, used as it is;
[0098] tetrahydrofuran (THF) (Aldrich): used as it is; [0099] iron
dichloride:tetrahydrofuran complex (1:1.5)
[FeCl.sub.2(THF).sub.1.5] (Aldrich): prepared from iron powder (Fe)
and iron trichloride (FeCl.sub.3), in tetrahydrofuran (THF) hot,
according to the method specified in Calderazzo F. et al., in
"Comptes Rendus Academie des Sciences" (1999), t. 2, SBrie II c,
pg. 311-319; [0100] iron dichloride tetrahydrate
(FeC.sub.2.4H.sub.2O) (Aldrich): purity 98%, used as it is; [0101]
methylaluminoxane (MAO) (toluene solution 10% by weight)
(Crompton): used as it is; [0102] 2,4-pentanedione (Aldrich): used
as it is; [0103] benzene (Aldrich): pure, .gtoreq.99.9%, distilled
over sodium (Na) in an inert atmosphere; [0104] aniline (Aldrich):
distilled at reduced pressure and stored in an inert atmosphere;
[0105] hydrochloric acid in 37% aqueous solution (Aldrich): used as
it is; [0106] o-toluidine (Aldrich): distilled at reduced pressure
and stored in an inert atmosphere; [0107] p-toluidine (Aldrich):
distilled at reduced pressure and stored in an inert atmosphere;
[0108] 2,6-di-iso-propylaniline (Aldrich): distilled at reduced
pressure and stored in an inert atmosphere; [0109] ethyl ether
(Aldrich): pure, .gtoreq.99%, distilled over sodium (Na) in an
inert atmosphere; [0110] 2,4,6-tri-methylaniline (Aldrich):
distilled at reduced pressure and stored in an inert atmosphere;
[0111] n-butyllithium (Aldrich): 2.5 M solution in hexane; [0112]
dichloromethane (CH.sub.2Cl.sub.2) (Acros): pure, .gtoreq.99.9%,
used as it is; Celite.RTM. 545 (Aldrich): used as it is; [0113]
hexane (Aldrich): pure, .gtoreq.99%, distilled over sodium (Na) in
an inert atmosphere; [0114] heptane (Aldrich): pure, .gtoreq.99%,
distilled over sodium (Na) in an inert atmosphere; [0115] methanol
(Carlo Erba, RPE): used as it is; [0116] toluene (Aldrich): pure,
.gtoreq.99.5%, distilled over sodium (Na) in an inert atmosphere;
1,3-butadiene (Air Liquide): pure, .gtoreq.99.5%, evaporated from
the container before each production, dried by passing it through a
molecular sieve packed column and condensed inside the reactor that
was pre-cooled to -20.degree. C.; [0117] isoprene (Aldrich): pure,
.gtoreq.99%, refluxed over calcium hydride for 2 hours, then
distilled "trap-to-trap" and stored in a nitrogen atmosphere at
4.degree. C.; hydrofluoric acid (HF) (40% aqueous solution)
(Aldrich): used as it is; [0118] sulfuric acid (H.sub.2SO.sub.4)
(96% aqueous solution) (Aldrich): used as it is, or diluted with
distilled water (1/5); [0119] nitric acid (HNO.sub.3) (70% aqueous
solution) (Aldrich): used as it is; [0120] sodium carbonate
(Na.sub.2CO.sub.3) (Aldrich): used as it is; [0121] silver nitrate
(AgNO.sub.3) (Aldrich): used as it is; [0122] deuterated
tetrachloroethylene (C.sub.2D.sub.2Cl.sub.4) (Acros): used as it
is; [0123] hexamethyldisiloxane (HMDS) (Acros): used as it is;
[0124] deuterated chloroform (CDCl.sub.3) (Acros): used as it is;
[0125] tetramethyldisiloxane (HMDS) (Acros): used as it is;
[0126] The analysis and characterization methods reported below
were used.
Elementary Analysis
a) Determination of Fe
[0127] For the determination of the quantity in weight of iron (Fe)
in the oxo-nitrogenated iron complexes object of the present
invention, an exactly weighted aliquot, operating in dry-box under
nitrogen flow, of about 30 mg-50 mg of sample, was placed in a 30
ml platinum crucible, together with a 1 ml mixture of 40%
hydrofluoric acid (HF), 0.25 ml of 96% sulfuric acid
(H.sub.2SO.sub.4) and 1 ml of 70% nitric acid (HNO.sub.3). The
crucible was then heated on a hot plate increasing the temperature
until white sulfur fumes appeared (about 200.degree. C.). The
mixture thus obtained was cooled to ambient temperature (20.degree.
C.-25.degree. C.) and 1 ml of 70% nitric acid (HNO.sub.3) was
added, then it was left again until fumes appeared. After repeating
the sequence another two times, a clear, almost colorless, solution
was obtained. 1 ml of nitric acid (HNO.sub.3) and about 15 ml of
water were then added cold, then heated to 80.degree. C. for about
30 minutes. The sample thus prepared was diluted with MilliQ pure
water until it weighed about 50 g, precisely weighed, to obtain a
solution on which the instrumental analytical determination was
performed using a Thermo Optek IRIS Advantage Duo ICP-OES (plasma
optical emission) spectrometer, for comparison with solutions of
known concentration. For this purpose, for every analyte, a
calibration curve was prepared in the range 0 ppm-10 ppm, measuring
calibration solutions by dilution by weight of certified
solutions.
[0128] The solution of sample prepared as above was then diluted
again by weight in order to obtain concentrations close to the
reference ones, before performing spectrophotometric measurement.
All the samples were prepared in double quantities. The results was
considered acceptable if the individual repeated test data did not
have a relative deviation of more than 2% with respect to their
mean value.
b) Determination of Chlorine
[0129] For said purpose, samples of the oxo-nitrogenated iron
complexes object of the present invention, about 30 mg-50 mg, were
precisely weighed in 100 ml glass beakers in dry-box under nitrogen
flow. 2 g of sodium carbonate (Na.sub.2CO.sub.3) were added and,
outside the dry-box, 50 ml of MilliQ water. It was brought to the
boil on the hot plate, under magnetic stirring, for about 30
minutes. It was left to cool, then 1/5 diluted sulfuric acid
(H.sub.2SO.sub.4) was added, until acid reaction and was then
titrated with 0.1 N silver nitrate (AgNO.sub.3) with a
potentiometric titrator.
c) Determination of Carbon, of Hydrogen and of Nitrogen
[0130] The determination of carbon, of hydrogen and of nitrogen, in
the oxo-nitrogenated iron complexes object of the present
invention, like in the ligands used for the purpose of the present
invention, was performed through a Carlo Erba automatic analyzer
Mod. 1106.
.sup.13C-HMR and .sup.1H-HMR Spectra
[0131] The .sup.13C-HMR and .sup.1H-HMR spectra were recorded using
a nuclear magnetic resonance spectrometer mod. Bruker Avance 400,
using deuterated tetrachloroethylene (C.sub.2D.sub.2Cl.sub.4) at
103.degree. C., and hexamethyldisiloxane (HDMS) as internal
standard, or using deuterated chloroform (CDCl.sub.3), at
25.degree. C., and tetramethylsilane (TMS) as internal standard.
For this purpose, polymeric solutions were used with concentrations
equal to 10% by weight with respect to the total weight of the
polymeric solution.
[0132] The microstructure of the polymers [i.e. 1,4-cis (%)
1,4-trans (%) and 1,2(%) unit content for polybutadiene and 1,4-cis
(%), 1,4-trans (%) and 3,4(%) unit content for polyisoprene] was
determined through the analysis of the aforementioned spectra based
on what is reported in literature by Mochel, V. D., in "Journal of
Polymer Science Part A-1: Polymer Chemistry" (1972), Vol. 10, Issue
4, pg. 1009-1018 for polybutadiene, and by Sato H. et al. in
"Journal of Polymer Science: Polymer Chemistry Edition" (1979),
Vol. 17, Issue 11, pg. 3551-3558, for polyisoprene.
FT-IR Spectra (Solid State-UATR)
[0133] The FT-IR spectra (solid state-UATR) were recorded using a
Bruker IFS 48 spectrophotometer equipped with a Thermo Spectra-Tech
horizontal ATR connection.
[0134] The section wherein the samples to be analyzed are placed is
a Fresnel ATR accessory (Shelton, Conn., USA) which uses crystals
of zirconium selenide (ZnSe) with an angle of incidence of
45.degree. in the horizontal direction.
[0135] The FT-IR spectra (solid state-UATR) of the oxo-nitrogenated
iron complexes object of the present invention, were obtained by
inserting samples of the oxo-nitrogenated iron complex to be
analyzed into said section.
I.R. Spectra
[0136] The I.R. (FT-IR) spectra were recorded through Thermo
Nicolet Nexus 670 and Bruker IFS 48 spectrophotometers.
[0137] The I.R. (FT-IR) spectra of the ligands used for the purpose
of the present invention, were obtained by dispersing the ligand to
be analyzed in anhydrous potassium bromide (KBr) (KBr disks), or in
Nujol solution.
[0138] The I.R. (FT-IR) spectra of the polymers were obtained from
polymeric films on potassium bromide (KBr) tablets, said films
being obtained through the deposition of a solution in hot
1,2-dichlorobenzene of the polymer to be analyzed. The
concentration of the polymeric solutions analyzed was equal to 10%
by weight with respect to the total weight of the polymeric
solution.
Determination of the Molecular Weight
[0139] The determination of the molecular weight (MW) of the
polymers obtained was performed through GPC ("Gel Permeation
Chromatography"), using the Waters.RTM. Alliance.RTM. GPC/V 2000
System by Waters Corporation which uses two detection lines:
"Refractive Index" (RI) and "Viscometer" operating under the
following conditions: [0140] two PLgel Mixed-B columns; [0141]
solvent/eluent: o-dichlorobenzene (Aldrich); [0142] flow rate: 0.8
ml/min; [0143] temperature: 145.degree. C.; [0144] molecular mass
calculation: Universal Calibration method.
[0145] The weight-average molecular weight (M.sub.w) and the
Polydispersion Index (PDI) are reported, corresponding to the ratio
M.sub.w/M.sub.n (M.sub.n=number-average molecular weight).
Mass Spectra
[0146] The mass spectra of the ligands used for the purpose of the
present invention were performed with a Trace DSQ single quadrupole
mass spectrometer (Thermo ISQ) in Electronic Ionization (El mode),
operating under the following conditions: [0147] scanning: from 35
amu to 600 amu (amu=atomic mass unit); [0148] temperature of the
source: 250.degree. C.; [0149] transfer line temperature:
300.degree. C.; [0150] capillary column: MDN-5S (Supelco)
(length=30 m; diameter=0.25 mm; stationary phase thickness=0.25
.mu.m); [0151] carrier gas: helium (He) with constant flow equal to
1 ml/min.
Example 1
Synthesis of Ligand Having Formula (L1)
##STR00004##
[0153] 5 g (50 mmoles) of 2,4-pentandione were placed in a 500 ml
flask equipped with a Dean-Stark trap for the azeotropic removal of
water, together with 100 ml of benzene, some drops of hydrochloric
acid and 4.66 g (50 mmoles) of aniline: the mixture obtained was
heated under reflux, for 24 hours. Subsequently, the mixture was
cooled to ambient temperature, filtered on a porous septum
obtaining a filtrate which was evaporated under vacuum obtaining a
solid product. The solid product thus obtained was dissolved in
ethyl ether (40 ml) and placed in the freezer for 24 hours,
obtaining a precipitate that was filtered and dried, under vacuum,
at ambient temperature, obtaining 7 g of a white crystalline
product (yield=80%) having formula (L1).
[0154] Elementary analysis [found (calculated for
C.sub.11H.sub.13NO)]: C: 75.20% (75.40%); H: 7.50% (7.48%); N:
8.00% (7.99%).
[0155] Molecular weight (MW): 175.23.
[0156] FT-IR (solid state-UATR) 1590 cm.sup.-1; 1571 cm.sup.-1.
[0157] .sup.1H-NMR (CD.sub.2Cl.sub.2, .delta. ppm): 12.49 (s, 1H
NH), 8.27 (d, 1H PyH), 7.34-7.28 (m, 2H ArH), 7.19-7.15 (m, 1H
ArH), 7.10-7.08 (m, 2H ArH), 5.18 (s, 1H CH), 2.09 (s, 3H
CH.sub.3), 1.97 (s, 3H CH.sub.3).
[0158] GC-MS: M.sup.+=m/z 175.
Example 2
Synthesis of Ligand Having Formula (L2)
##STR00005##
[0160] 30 g (300 mmoles) of 2,4-pentandione were placed in a 500 ml
flask equipped with a Dean-Stark trap for the azeotropic removal of
water, together with 300 ml of benzene, some drops of hydrochloric
acid and 32.1 g (300 mmoles) of o-toluidine: the mixture obtained
was heated under reflux, for 24 hours. Subsequently, the mixture
was cooled to ambient temperature, filtered on a porous septum
obtaining a filtrate which was evaporated under vacuum obtaining a
solid product. The solid product thus obtained was dissolved in
ethyl ether (100 ml) and placed in the freezer for 24 hours,
obtaining a precipitate that was filtered and dried, under vacuum,
at ambient temperature, obtaining 35 g of a white crystalline
product (yield=61%) having formula (L2).
[0161] Elementary analysis [found (calculated for
C.sub.12H.sub.15NO)]: C: 76.18% (76.16%); H: 7.97% (7.99%); N:
7.37% (7.40%).
[0162] Molecular weight (MW): 189.26.
[0163] FT-IR (solid state-UATR) 1595 cm.sup.-1; 1560 cm.sup.-1.
[0164] .sup.1H-NMR (CD.sub.2Cl.sub.2, .delta. ppm): 1.87 (s, 3H
CH.sub.3CN), 2.11 (s, 3H CH.sub.3CO), 2.28 (s, 3H
CeH.sub.2CH.sub.3), 5.20 (s, 1H CH), 7.06-7.23 (s, 4H
C.sub.6H.sub.4), 12.35 (s, 1H NH).
[0165] GC-MS: M.sup.+=m/z 189.
Example 3
Synthesis of Ligand Having Formula (L3)
##STR00006##
[0167] 5 g (50 mmoles) of 2,4-pentandione were placed in a 500 ml
flask equipped with a Dean-Stark trap for the azeotropic removal of
water, together with 75 ml of benzene, some drops of hydrochloric
acid and 5.35 g (50 mmoles) of p-toluidine: the mixture obtained
was heated under reflux, for 24 hours. Subsequently, the mixture
was cooled to ambient temperature, filtered on a porous septum
obtaining a filtrate which was evaporated under vacuum obtaining a
solid product. The solid product thus obtained was dissolved in
ethyl ether (10 ml) and placed in the freezer for 24 hours,
obtaining a precipitate that was filtered and dried, under vacuum,
at ambient temperature, obtaining 5.7 g of a white crystalline
product (yield=60%) having formula (L3).
[0168] Elementary analysis [found (calculated for
C.sub.12H.sub.15NO)]: C: 76.13% (76.16%); H: 7.87% (7.99%); N:
7.36% (7.40%).
[0169] Molecular weight (MW): 189.26.
[0170] FT-IR (KBr): 1609 cm.sup.-1; 1565 cm.sup.-1.
[0171] .sup.1H-NMR (CD.sub.2Cl.sub.2, 5 ppm): 1.93 (s, 3H
CH.sub.3), 2.05 (s, 3H CH.sub.3), 2.31 (s, 3H CH.sub.3), 5.15 (s,
1H CH), 6.98 (d, 2H Ph), 7.13 (d, 2H Ph), 12.38 (s, 1H, NH).
[0172] GC-MS: M.sup.+=m/z 189.
Example 4
Synthesis of Ligand Having Formula (L4)
##STR00007##
[0174] 5 g (50 mmoles) of 2,4-pentandione were placed in a 500 ml
flask equipped with a Dean-Stark trap for the azeotropic removal of
water, together with 75 ml of benzene, some drops of hydrochloric
acid and 8.9 g (50 mmoles) of 2,6-di-iso-propylaniline: the mixture
obtained was heated under reflux, for 24 hours. Subsequently, the
mixture was cooled to ambient temperature, filtered on a porous
septum obtaining a filtrate which was evaporated under vacuum
obtaining a solid product. The solid product thus obtained was
dissolved in ethyl ether (10 ml) and placed in the freezer for 24
hours, obtaining a precipitate that was filtered and dried, under
vacuum, at ambient temperature, obtaining 6.5 g of a white
crystalline product (yield=50%) having formula (L4).
[0175] Elementary analysis [found (calculated for
C.sub.17H.sub.25NO)]: C: 78.60% (78.72%); H: 9.60% (9.71%); N:
5.32% (5.40%).
[0176] Molecular weight (MW): 259.39.
[0177] FT-IR (KBr): 1606 cm.sup.-1; 1567 cm.sup.-1.
[0178] .sup.1H NMR (CDCl.sub.3, .delta. ppm): 1.11 (d, 6H,
CH(CH.sub.3).sub.2), 1.18 (d, 6H, CH(CH.sub.3).sub.2), 1.60 (s, 3H
CH.sub.3CN), 2.10 (s, 3H CH.sub.3CO), 3.00 (sept, 2H, CHMe.sub.2),
5.19 (s, 1H CHCO), 7.12-7.28 (m, 3H, Ar), 12.05 (s, 1H NH).
[0179] GC-MS: M.sup.+=m/z 259.
Example 5
Synthesis of Ligand Having Formula (L5)
##STR00008##
[0181] 5 g (50 mmoles) of 2,4-pentandione were placed in a 500 ml
flask equipped with a Dean-Stark trap for the azeotropic removal of
water, together with 75 ml of benzene, some drops of hydrochloric
acid and 6.76 g (50 mmoles) of 2,4,6-tri-methylaniline: the mixture
obtained was heated under reflux, for 24 hours. Subsequently, the
mixture was cooled to ambient temperature, filtered on a porous
septum obtaining a filtrate which was evaporated under vacuum
obtaining a solid product. The solid product thus obtained was
dissolved in ethyl ether (10 ml) and placed in the freezer for 24
hours, obtaining a precipitate that was filtered and dried, under
vacuum, at ambient temperature, obtaining 4.8 g of a light yellow
product (yield=44%) having formula (L5).
[0182] Elementary analysis [found (calculated for
C.sub.14H.sub.19NO)]: C: 77.40% (77.38%); H: 9.00% (8.81%); N:
6.32% (6.45%).
[0183] Molecular weight (MW): 217.31.
[0184] FT-IR (solid state, ATR): 1606 cm.sup.-1; 1567
cm.sup.-1.
[0185] .sup.1H-NMR (CD.sub.2Cl.sub.2, .delta. ppm): 1.6 (s, 3H
CH.sub.3CN), 2.05 (s, 3H CH.sub.3CO), 2.18 (s, 6H
2-C.sub.6H.sub.2CH.sub.3), 2.28 (s, 3H 4-C.sub.6H.sub.2CH.sub.3),
5.21 (s, 1H CH), 6.92 (s, 2H C.sub.6H.sub.2), 11.82 (s, 1H NH).
[0186] GC-MS: M.sup.+=m/z 217.
Example 6
Synthesis of FeCl.sub.2(L1) [Sample MG101]
##STR00009##
[0188] In a 100 ml flask, a solution of n-butyllithium (2.5 M in
hexane; 0.6 ml; 1.43 mmoles) was added to a solution of the ligand
having formula (L1) (250 mg; 1.43 mmoles), obtained as described in
Example 1, in hexane (40 ml), maintained at -40.degree. C.: the
solution obtained was left to return to ambient temperature slowly
and maintained at said temperature, under stirring, for about 4
hours. Subsequently, iron trichloride (FeCl.sub.3) (232 mg; 1.43
mmoles; molar ratio L1/Fe=1) was added: the brown suspension
obtained was left, under stirring, at ambient temperature, for
about 5 hours. The solvent was then removed under vacuum, at
ambient temperature, and the residue obtained was suspended in
dichloromethane (CH.sub.2Cl.sub.2) (20 ml). The suspension obtained
was filtered on Celite.RTM. 545 and the solution obtained was
dried, under vacuum, at ambient temperature, obtaining 275 mg of a
dark brown solid product corresponding to the complex
FeCl.sub.2(L1), equal to a 64% conversion with respect to the iron
trichloride (FeCl.sub.3) loaded.
[0189] Elementary analysis [found (calculated for
C.sub.11H.sub.12Cl.sub.2FeNO)]: C: 43.45% (43.89%); H: 4.31%
(4.02%); N: 4.48% (4.65%); Cl: 22.99% (23.56%); Fe: 17.95%
(18.55%).
[0190] FIG. 1 shows the FT-IR spectrum (solid state-UATR) of the
complex FeC.sub.2(L1) obtained.
Example 7
[0191] Synthesis of FeCl.sub.2(L1).sub.2 [Sample MG110]
##STR00010##
[0192] In a 100 ml flask, the iron dichloride:tetrahydrofuran
complex (1:1.5) [FeCl.sub.2(THF).sub.1.5] (237 mg; 1.01 mmoles;
molar ratio L1/Fe=2) was added to a solution of the ligand having
formula (L1) (353 mg; 2.02 mmoles), obtained as described in
Example 1, in tetrahydrofuran (THF) (40 ml): the intense orange
mixture obtained was maintained, under stirring, at ambient
temperature, for 3 hours. The solvent was then removed under vacuum
and the residue obtained was dried under vacuum, at ambient
temperature, obtaining 450 mg of an orange solid product
corresponding to the complex FeCl.sub.2(L1).sub.2, equal to a 93%
conversion with respect to the iron dichloride:tetrahydrofuran
complex (1:1.5) [FeCl.sub.2(THF).sub.1.] loaded.
[0193] Elementary analysis [found (calculated for
C.sub.22H.sub.26Cl.sub.2FeN.sub.2O.sub.2)]: C: 55.95% (55.37%); H:
5.01% (5.49%); N: 5.48% (5.87%); Cl: 15.01% (14.85%); Fe: 11.25%
(11.70%).
[0194] FIG. 2 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L1).sub.2 obtained.
Example 8
Synthesis of FeCl.sub.2(L2) [Sample MG199]
##STR00011##
[0196] In a 100 ml flask, a solution of n-butyllithium (2.5 M in
hexane; 0.46 ml; 1.14 mmoles) was added to a solution of the ligand
having formula (L2) (215 mg; 1.14 mmoles), obtained as described in
Example 2, in hexane (30 ml), maintained at -40.degree. C.: the
solution obtained was left to return to ambient temperature slowly
and maintained at said temperature, under stirring, for about 4
hours. Subsequently, iron trichloride (FeCl.sub.3) (185 mg; 1.14
mmoles; molar ratio L2/Fe=1) was added: the brown suspension
obtained was left, under stirring, at ambient temperature, for
about 5 hours. The solvent was then removed under vacuum, at
ambient temperature, and the residue obtained was suspended in
dichloromethane (CH.sub.2Cl.sub.2) (20 ml). The suspension obtained
was filtered on Celite.RTM. 545 and the solution obtained was
dried, under vacuum, at ambient temperature, obtaining 224 mg of a
purple solid product corresponding to the complex FeCl.sub.2(L2),
equal to a 62% conversion with respect to the iron trichloride
(FeCl.sub.3) loaded.
[0197] Elementary analysis [found (calculated for
C.sub.12H.sub.14Cl.sub.2FeNO)]: C: 45.05% (45.75%); H: 4.03%
(4.48%); N: 4.12% (4.45%); CI: 22.00% (22.51%); Fe: 17.54%
(17.73%).
[0198] FIG. 3 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L2) obtained.
Example 9
[0199] Synthesis of FeC.sub.2(L2).sub.2 [Sample MG114]
##STR00012##
[0200] In a 100 ml flask, iron dichloride tetrahydrate
(FeCl.sub.2.4H.sub.2O) (638 mg; 3.38 mmoles; molar ratio L2/Fe=2)
was added to a solution of the ligand having formula (L2) (353 mg;
2.02 mmoles), obtained as described in Example 2, in
tetrahydrofuran (THF) (40 ml): the intense orange mixture obtained
was maintained, under stirring, at ambient temperature, for 3
hours. The solvent was then removed under vacuum and the residue
obtained was dried under vacuum, at ambient temperature, obtaining
700 mg of an orange solid product corresponding to the complex
FeCl.sub.2(L2).sub.2, equal to a 93% conversion with respect to the
iron dichloride tetrahydrate (FeCl.sub.2-4H.sub.2O) loaded.
[0201] Elementary analysis [found (calculated for
C.sub.24H.sub.30Cl.sub.2FeN.sub.2O.sub.2)]: C: 56.95% (57.05%); H:
5.51% (5.98%); N: 5.48% (5.54%); Cl: 14.51% (14.03%); Fe: 11.95%
(11.05%).
[0202] FIG. 4 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L2).sub.2 obtained.
Example 10
Synthesis of FeCl.sub.2(L3) [Sample MG200]
##STR00013##
[0204] In a 100 ml flask, a solution of n-butyllithium (2.5 M in
hexane; 0.44 ml; 1.10 mmoles) was added to a solution of the ligand
having formula (L3) (208 mg; 1.10 mmoles), obtained as described in
Example 3, in hexane (30 ml), maintained at -40.degree. C.: the
solution obtained was left to return to ambient temperature slowly
and maintained at said temperature, under stirring, for about 4
hours. Subsequently, iron trichloride (FeCl.sub.3) (179 mg; 1.10
mmoles; molar ratio L3/Fe=1) was added: the brown suspension
obtained was left, under stirring, at ambient temperature, for
about 5 hours. The solvent was then removed under vacuum, at
ambient temperature, and the residue obtained was suspended in
dichloromethane (CH.sub.2Cl.sub.2) (20 ml). The suspension obtained
was filtered on Celite.RTM. 545 and the solution obtained was
dried, under vacuum, at ambient temperature, obtaining 184 mg of a
purple solid product corresponding to the complex FeCl.sub.2(L3),
equal to a 53% conversion with respect to the iron trichloride
(FeCl.sub.3) loaded.
[0205] Elementary analysis [found (calculated for
C.sub.12H.sub.14Cl.sub.2FeNO)]: C: 44.99% (45.75%); H: 4.31%
(4.48%); N: 4.56% (4.45%); Cl: 22.20% (22.51%); Fe: 18.05%
(17.73%).
[0206] FIG. 5 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L3) obtained.
Example 11
[0207] Synthesis of FeCl.sub.2(L3).sub.2 [Sample MG137]
##STR00014##
[0208] In a 100 ml flask, the iron dichloride:tetrahydrofuran
complex (1:1.5) [FeCl.sub.2(THF).sub.1.5] (94 mg; 0.36 mmoles;
molar ratio L3/Fe=2) was added to a solution of the ligand having
formula (L3) (135 mg; 0.71 mmoles), obtained as described in
Example 3, in tetrahydrofuran (THF) (20 ml): the intense orange
mixture obtained was maintained, under stirring, at ambient
temperature, for 3 hours. The solvent was then removed under vacuum
and the residue obtained was washed with heptane (2.times.10 ml)
and dried under vacuum, at ambient temperature, obtaining 161 mg of
an orange solid product corresponding to the complex
FeCl.sub.2(L3).sub.2, equal to an 89% conversion with respect to
the iron dichloride:tetrahydrofuran complex (1:1.5)
[FeCl.sub.2(THF).sub.1.5] loaded.
[0209] Elementary analysis [found (calculated for
C.sub.24H.sub.30Cl.sub.2FeN.sub.2O.sub.2)]: C: 56.75% (57.05%); H:
5.61% (5.98%); N: 5.75% (5.54%); Cl: 14.81% (14.03%); Fe: 11.55%
(11.05%).
[0210] FIG. 6 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L3).sub.2 obtained.
Example 12
Synthesis of FeCl.sub.2(L4) [Sample MG201]
##STR00015##
[0212] In a 100 ml flask, a solution of n-butyllithium (2.5 M in
hexane; 0.28 ml; 0.69 mmoles) was added to a solution of the ligand
having formula (L4) (180 mg; 0.69 mmoles), obtained as described in
Example 4, in hexane (15 ml), maintained at -40.degree. C.: the
solution obtained was left to return to ambient temperature slowly
and maintained at said temperature, under stirring, for about 4
hours. Subsequently, iron trichloride (FeCl.sub.3) (113 mg; 0.69
mmoles; molar ratio L4/Fe=1) was added: the brown suspension
obtained was left, under stirring, at ambient temperature, for
about 5 hours. The solvent was then removed under vacuum, at
ambient temperature, and the residue obtained was suspended in
dichloromethane (CH.sub.2Cl.sub.2) (20 ml). The suspension obtained
was filtered on Celite.RTM. 545 and the solution obtained was
dried, under vacuum, at ambient temperature, obtaining 205 mg of a
purple solid product corresponding to the complex FeCl.sub.2(L4),
equal to a 77% conversion with respect to the iron trichloride
(FeCl.sub.3) loaded.
[0213] Elementary analysis [found (calculated for
C.sub.17H.sub.24Cl.sub.2FeNO)]: C: 52.56% (53.02%); H: 6.00%
(6.28%); N: 3.01% (3.64%); Cl: 17.99% (18.41%); Fe: 15.01%
(14.50%).
[0214] FIG. 7 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L4) obtained.
Example 13
[0215] Synthesis of FeCl.sub.2(L4).sub.2 [Sample MG145]
##STR00016##
[0216] In a 100 ml flask, the iron dichloride:tetrahydrofuran
complex (1:1.5) [FeCl.sub.2(THF), 0.5] (134 mg; 0.57 mmoles; molar
ratio L4/Fe=2) was added to a solution of the ligand having formula
(L4) (296 mg; 1.14 mmoles), obtained as described in Example 4, in
tetrahydrofuran (THF) (20 ml): the intense orange mixture obtained
was maintained, under stirring, at ambient temperature, for 3
hours. The solvent was then removed under vacuum and the residue
obtained was washed with heptane (2.times.10 ml) and dried under
vacuum, at ambient temperature, obtaining 292 mg of an orange solid
product corresponding to the complex FeCl.sub.2(L4).sub.2, equal to
a 79% conversion with respect to the iron
dichloride:tetrahydrofuran complex (1:1.5)
[FeCl.sub.2(THF).sub.1.5] loaded.
[0217] Elementary analysis [found (calculated for
C.sub.34H.sub.50Cl.sub.2FeN.sub.2O.sub.2)]: C: 63.75% (63.26%); H:
7.61% (7.81%); N: 4.75% (4.34%); Cl: 10.21% (10.98%); Fe: 8.15%
(8.65%).
[0218] FIG. 8 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L4).sub.2 obtained.
Example 14
Synthesis of FeCl.sub.2(L5) [Sample MG102]
##STR00017##
[0220] In a 100 ml flask, a solution of n-butyllithium (2.5 M in
hexane; 0.55 ml; 1.37 mmoles) was added to a solution of the ligand
having formula (L5) (298 mg; 1.37 mmoles), obtained as described in
Example 5, in hexane (40 ml), maintained at -40.degree. C.: the
solution obtained was left to return to ambient temperature slowly
and maintained at said temperature, under stirring, for about 4
hours. Subsequently, iron trichloride (FeCl.sub.3) (223 mg; 1.37
mmoles; molar ratio L5/Fe=1) was added: the brown suspension
obtained was left, under stirring, at ambient temperature, for
about 5 hours. The solvent was then removed under vacuum, at
ambient temperature, and the residue obtained was suspended in
dichloromethane (CH.sub.2Cl.sub.2) (20 ml). The suspension obtained
was filtered on Celite.RTM. 545 and the solution obtained was
dried, under vacuum, at ambient temperature, obtaining 383 mg of a
purple solid product corresponding to the complex FeCl.sub.2(L5),
equal to a 74% conversion with respect to the iron trichloride
(FeCl.sub.3) loaded.
[0221] Elementary analysis [found (calculated for
C.sub.14H.sub.18Cl.sub.2FeNO)]: C: 49.75% (49.02%); H: 5.61%
(5.29%); N: 4.43% (4.08%); CI: 20.21% (20.67%); Fe: 15.85%
(16.28%).
[0222] FIG. 9 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L5) obtained.
Example 15
[0223] Synthesis of FeCl.sub.2(L5).sub.2 [Sample MG112]
##STR00018##
[0224] In a 100 ml flask, the iron dichloride:tetrahydrofuran
complex (1:1.5) [FeCl.sub.2(THF).sub.1.5] (309 mg; 1.32 mmoles;
molar ratio L5/Fe=2) was added to a solution of the ligand having
formula (L5) (571 mg; 2.64 mmoles), obtained as described in
Example 5, in tetrahydrofuran (THF) (40 ml): the intense orange
mixture obtained was maintained, under stirring, at ambient
temperature, for 3 hours. The solvent was then removed under vacuum
and the residue obtained was washed with heptane (2.times.10 ml)
and dried under vacuum, at ambient temperature, obtaining 651 mg of
an orange solid product corresponding to the complex
FeCl.sub.2(L5).sub.2, equal to an 88% conversion with respect to
the iron dichloride:tetrahydrofuran complex (1:1.5)
[FeCl.sub.2(THF).sub.1.5] loaded.
[0225] Elementary analysis [found (calculated for
C.sub.28H.sub.38Cl.sub.2FeN.sub.2O.sub.2)]: C: 59.25% (59.91%); H:
6.61% (6.82%); N: 4.78% (4.99%); CI: 12.21% (12.63%); Fe: 9.25%
(9.95%).
[0226] FIG. 10 shows the FT-IR spectrum (solid state-UATR) of the
complex FeCl.sub.2(L5).sub.2 obtained.
Example 16 (G1470)
[0227] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 8.2 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L1)
complex [sample MG101] (1.5 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 3.01 mg) obtained as described in Example 6.
[0228] The whole was kept under magnetic stirring, at ambient
temperature, for 3 minutes. The polymerization was then stopped by
adding 2 ml of methanol containing some drops of hydrochloric acid.
The polymer obtained was then coagulated by adding 40 ml of a
methanol solution containing 4% of Irganox.RTM. 1076 antioxidant
(Ciba) obtaining 0.754 g of polybutadiene having a mixed
1,4-cis/1,2 structure: further characteristics of the process and
of the polybutadiene obtained are reported in Table 1.
[0229] FIG. 11 shows the FT-IR spectrum of the polybutadiene
obtained.
[0230] FIG. 12 shows the GPC ("Gel Permeation Chromatography")
curve of the polybutadiene obtained.
[0231] FIG. 13 shows the .sup.1H-NMR (top) and .sup.13C-NMR
(bottom) spectra of the polybutadiene obtained.
Example 17 (G1471)
[0232] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 7.3 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L1).sub.2
complex [sample MG110] (2.4 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 4.8 mg) obtained as described in Example 7. The whole was
kept under magnetic stirring, at ambient temperature, for 3
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining 1.4
g of polybutadiene having a mixed 1,4-cis/1,2 structure: further
characteristics of the process and of the polybutadiene obtained
are reported in Table 1.
[0233] FIG. 14 shows the FT-IR spectrum of the polybutadiene
obtained.
[0234] FIG. 15 shows the GPC ("Gel Permeation Chromatography")
curve of the polybutadiene obtained.
[0235] FIG. 16 shows the .sup.1H-NMR (top) and .sup.13C-NMR
(bottom) spectra of the polybutadiene obtained.
Example 18 (G1474)
[0236] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 10.45 ml
of toluene were added and the temperature of the solution thus
obtained was brought to -50.degree. C. Then, methylaluminoxane
(MAO) in toluene solution (3.15 ml; 5.times.10.sup.-3 moles, equal
to about 0.29 g) was added and, subsequently, the
FeCl.sub.2(L1).sub.2 complex [sample MG110] (2.4 ml of toluene
solution at a concentration equal 2 mg/ml; 1.times.10.sup.-5 moles,
equal to about 4.8 mg) obtained as described in Example 7. The
whole was kept under magnetic stirring, at -50.degree. C., for 120
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox 1076 antioxidant (Ciba) obtaining 0.456 g
of polybutadiene having a mixed 1,4-cis/1,2 structure: further
characteristics of the process and of the polybutadiene obtained
are reported in Table 1.
[0237] FIG. 17 shows the FT-IR spectrum of the polybutadiene
obtained.
Example 19 (IP185)
[0238] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 8.1 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L2)
complex [sample MG199] (1.6 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 3.15 mg) obtained as described in Example 8. The whole was
kept under magnetic stirring, at ambient temperature, for 120
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.580 g of polybutadiene having a mixed 1,4-cis/1,2 structure:
further characteristics of the process and of the polybutadiene
obtained are reported in Table 1.
[0239] FIG. 18 shows the FT-R spectrum of the polybutadiene
obtained.
Example 20 (IP180)
[0240] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 7.2 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L2).sub.2
complex [sample MG114] (2.5 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 5.05 mg) obtained as described in Example 9. The whole was
kept under magnetic stirring, at ambient temperature, for 120
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
1.028 g of polybutadiene having a mixed 1,4-cis/1,2 structure:
further characteristics of the process and of the polybutadiene
obtained are reported in Table 1.
Example 21 (IP186)
[0241] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 8.1 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L3)
complex [sample MG101] (1.6 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 3.15 mg) obtained as described in Example 10. The whole was
kept under magnetic stirring, at ambient temperature, for 120
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.438 g of polybutadiene having a mixed 1,4-cis/1,2 structure:
further characteristics of the process and of the polybutadiene
obtained are reported in Table 1.
[0242] FIG. 19 shows the FT-IR spectrum of the polybutadiene
obtained.
Example 22 (IP140)
[0243] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 7.2 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L3).sub.2
complex [sample MG137] (2.5 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 5.05 mg) obtained as described in Example 11. The whole was
kept under magnetic stirring, at ambient temperature, for 480
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.262 g of polybutadiene having a mixed 1,4-cis/1,4-trans/1,2
structure: further characteristics of the process and of the
polybutadiene obtained are reported in Table 1.
[0244] FIG. 20 shows the FT-IR spectrum of the polybutadiene
obtained.
[0245] FIG. 21 shows the .sup.1H-NMR (top) and .sup.13C-NMR
(bottom) spectra of the polybutadiene obtained.
Example 23 (IP184)
[0246] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 7.8 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L4)
complex [sample MG201] (1.9 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 3.85 mg) obtained as described in Example 12. The whole was
kept under magnetic stirring, at ambient temperature, for 5760
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.331 g of polybutadiene having a mixed 1,4-cis/1,4-trans/1,2
structure: further characteristics of the process and of the
polybutadiene obtained are reported in Table 1.
[0247] FIG. 22 shows the FT-IR spectrum of the polybutadiene
obtained.
Example 24 (IP141)
[0248] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 6.5 ml of
toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L4).sub.2
complex [sample MG145] (3.2 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 6.46 mg) obtained as described in Example 13.
[0249] The whole was kept under magnetic stirring, at ambient
temperature, for 180 minutes.
[0250] The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.561 g of polybutadiene having a mixed 1,4-cis/1,4-trans/1,2
structure: further characteristics of the process and of the
polybutadiene obtained are reported in Table 1.
[0251] FIG. 23 shows the FT-IR spectrum of the polybutadiene
obtained.
[0252] FIG. 24 shows the GPC ("Gel Permeation Chromatography")
curve of the polybutadiene obtained.
Example 25 (G1472)
[0253] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 7.98 ml
of toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeCl.sub.2(L5)
complex [sample MG102] (1.72 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 3.43 mg) obtained as described in Example 14. The whole was
kept under magnetic stirring, at ambient temperature, for 5760
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.290 g of polybutadiene having a mixed 1,4-cis/1,4-trans/1,2
structure. Further characteristics of the process and of the
polybutadiene obtained are reported in Table 1.
[0254] FIG. 25 shows the FT-IR spectrum of the polybutadiene
obtained.
Example 26 (G1473)
[0255] 2 ml of 1,3-butadiene equal to about 1.4 g were condensed,
cold (-20.degree. C.) in a 25 ml test tube. Subsequently, 6.89 ml
of toluene were added and the temperature of the solution thus
obtained was brought to 20.degree. C. Then, methylaluminoxane (MAO)
in toluene solution (6.3 ml; 1.times.10.sup.-2 moles, equal to
about 0.58 g) was added and, subsequently, the FeC.sub.2(L5).sub.2
complex [sample MG112] (2.8 ml of toluene solution at a
concentration equal to 2 mg/ml; 1.times.10.sup.-5 moles, equal to
about 5.6 mg) obtained as described in Example 15. The whole was
kept under magnetic stirring, at ambient temperature, for 390
minutes. The polymerization was then stopped by adding 2 ml of
methanol containing some drops of hydrochloric acid. The polymer
obtained was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.417 g of polybutadiene having a mixed 1,4-cis/1,2 structure:
further characteristics of the process and of the polybutadiene
obtained are reported in Table 1.
[0256] FIG. 26 shows the FT-IR spectrum of the polybutadiene
obtained.
[0257] FIG. 27 shows the .sup.1H-NMR (top) and .sup.13C-NMR
(bottom) spectra of the polybutadiene obtained.
Example 27 (IP126)
[0258] 7.3 ml of toluene were inserted into a 25 ml test tube and,
subsequently, 2 ml of isoprene equal to about 1.36 g. Then
methylaluminoxane (MAO) in toluene solution (6.3 ml;
1.times.10.sup.-2 moles, equal to about 0.58 g) was added and,
subsequently, the FeCl.sub.2(L1).sub.2 complex [sample MG110] (2.48
ml of toluene solution at a concentration equal to 2 mg/ml;
1.times.10.sup.-5 moles, equal to about 4.8 mg) obtained as
described in Example 7. The whole was kept under magnetic stirring,
at ambient temperature, for 180 minutes. The polymerization was
then stopped by adding 2 ml of methanol containing some drops of
hydrochloric acid. The polymer obtained was then coagulated by
adding 40 ml of a methanol solution containing 4% of Irganox 1076
antioxidant (Ciba) obtaining 0.553 g of polyisoprene having a mixed
1,4-cis/3,4 structure: further characteristics of the process and
of the polyisoprene obtained are reported in Table 2.
[0259] FIG. 28 shows the FT-IR spectrum of the polyisoprene
obtained.
Example 28 (IP143)
[0260] 6.5 ml of toluene were inserted into a 25 ml test tube, at
ambient temperature, and, subsequently, 2 ml of isoprene equal to
about 1.36 g. Then methylaluminoxane (MAO) in toluene solution (6.3
ml; 1.times.10.sup.-2 moles, equal to about 0.58 g) was added and,
subsequently, the FeCl.sub.2(L4).sub.2 complex [sample MG145] (3.2
ml of toluene at a concentration equal to 2 mg/ml;
1.times.10.sup.-5 moles, equal to about 6.4 mg) obtained as
described in Example 13. The whole was kept under magnetic
stirring, at ambient temperature, for 600 minutes. The
polymerization was then stopped by adding 2 ml of methanol
containing some drops of hydrochloric acid. The polymer obtained
was then coagulated by adding 40 ml of a methanol solution
containing 4% of Irganox.RTM. 1076 antioxidant (Ciba) obtaining
0.502 g of polyisoprene having a mixed 1,4-cis/3,4 structure:
further characteristics of the process and of the polyisoprene
obtained are reported in Table 2.
[0261] FIG. 29 shows the FT-IR spectrum of the polyisoprene
obtained.
TABLE-US-00001 TABLE 1 Polymerization of 1,3-butadiene with
catalytic systems comprising iron complexes Conver- 1,4- 1,4- Exam-
Time sion cis trans 1.2 M.sub.w ple (min) (%) (%) (%) (%) (g
.times. mol.sup.-1) M.sub.w/M.sub.n 16 3 53.9 46.6 0 53.4 575000
2.0 17 3 100 44.3 0 55.7 402000 1.9 18 120 32.1 47.5 0 52.5 818000
2.1 19 120 41.4 46.1 0 53.9 560500 2.1 20 120 73.4 49.7 0 50.3
455000 1.8 21 1210 31.3 53.5 0 46.5 492000 2.0 22 480 18.7 51.6 4
44.4 344000 1.9 23 5760 23.6 75.7 4.9 19.4 297500 2.2 24 180 40.1
81.0 6.9 12.1 154500 2.1 25 5760 20.7 80.6 7.1 12.3 283000 2.2 26
390 29.8 80.1 0 19.9 164500 2.1
TABLE-US-00002 TABLE 2 Polymerization of isoprene with catalytic
systems comprising iron complexes Conver- 1,4- 1,4- Exam- Time sion
cis trans 3.4 M.sub.w ple (min) (%) (%) (%) (%) (g .times.
mol.sup.-1) M.sub.w/M.sub.n 27 180 40.7 39.4 0 60.6 175000 2.0 28
600 36.9 33.5 0 66.5 97500 1.9
* * * * *
References