U.S. patent application number 10/976386 was filed with the patent office on 2005-05-26 for electrophotographic organophotoreceptors with novel charge transport compounds.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Jain, Ritu, Jubran, Nusrallah, Katrtzky, Alan R., Law, Kam W., Maimait, Rexiat, Tokarski, Zbigniew.
Application Number | 20050112490 10/976386 |
Document ID | / |
Family ID | 27578797 |
Filed Date | 2005-05-26 |
United States Patent
Application |
20050112490 |
Kind Code |
A1 |
Law, Kam W. ; et
al. |
May 26, 2005 |
Electrophotographic organophotoreceptors with novel charge
transport compounds
Abstract
A novel charge transport compound, a novel process using that
novel compound and an organophotoreceptor includes: (a) a novel
charge transport compound having the formula 1 where R.sub.1 and
R.sub.2 are selected so that R.sub.1 and R.sub.2 form, with the
included nitrogen atom, a group selected from the group consisting
of heterocyclic rings, aromatic rings, and dinaphthylamine; or
R.sub.1 comprises an aryl group and R.sub.2 comprises a group
selected from the group consisting of sulfolanyl,
4-(9H-fluoren-9-ylidene)benzyl, pyrrolyl, pyrazolyl,
benzotriazolyl, stilbenyl, tetrazolyl; or R.sub.1 comprises
hydrogen, an alkyl group, an aryl group and R.sub.2 comprises
sulfonylphenyl. R.sub.3 is hydrogen, an alkyl group, an aryl group,
a heterocyclic group or a hydrocarbon group; and Q is a 3-carbazole
group; (b) a charge generating compound; and (c) an electrically
conductive substrate.
Inventors: |
Law, Kam W.; (Woodbury,
MN) ; Jubran, Nusrallah; (St. Paul, MN) ;
Tokarski, Zbigniew; (Woodbury, MN) ; Katrtzky, Alan
R.; (Gainesville, FL) ; Jain, Ritu;
(Gainesville, FL) ; Maimait, Rexiat; (Cincinnati,
OH) |
Correspondence
Address: |
Patterson, Thuente, Skaar & Christensen, P.A.
4800 IDS Center
80 South 8th Street
Minneapolis
MN
55402-2100
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
|
Family ID: |
27578797 |
Appl. No.: |
10/976386 |
Filed: |
October 29, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10976386 |
Oct 29, 2004 |
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10215359 |
Aug 9, 2002 |
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60311601 |
Aug 10, 2001 |
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60314055 |
Aug 22, 2001 |
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60314047 |
Aug 22, 2001 |
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60317086 |
Sep 4, 2001 |
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60317088 |
Sep 4, 2001 |
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60323782 |
Sep 20, 2001 |
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60323781 |
Sep 20, 2001 |
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60325716 |
Sep 28, 2001 |
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60330381 |
Oct 18, 2001 |
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Current U.S.
Class: |
430/125.3 |
Current CPC
Class: |
G03G 5/0627 20130101;
C07D 409/12 20130101; C07D 209/86 20130101; G03G 5/0629 20130101;
G03G 5/06 20130101; G03G 5/0631 20130101; G03G 5/0633 20130101;
G03G 5/0614 20130101; C07D 403/12 20130101; G03G 5/0616 20130101;
G03G 5/062 20130101; G03G 5/0642 20130101 |
Class at
Publication: |
430/126 |
International
Class: |
G03G 015/08; G03G
015/14 |
Claims
What is claimed is:
1. An electrophotographic imaging process comprising: (a) applying
an electrical charge to a surface of an organophotoreceptor
comprising (i) a charge transport compound having the formula 32
where R.sub.1 comprises an aryl group and R.sub.2 comprises a group
selected from the group consisting of sulfolanyl,
4-(9H-fluoren-9-ylidene)benzyl, pyrrolyl, pyrazolyl,
benzotriazolyl, stilbenyl, and tetrazolyl group; or R.sub.1
comprises hydrogen atom, an alkyl group, or an aryl group and
R.sub.2 comprises a sulfonylphenyl group; R.sub.3 is hydrogen, an
alkyl group, an aryl group, a heterocyclic group or a hydrocarbon
group; and Q is a 3-carbazole group; (ii) a charge generating
compound; and (iii) an electrically conductive substrate; (b)
imagewise exposing said surface of said organophotoreceptor to
radiation to dissipate charge in selected areas and thereby form a
pattern of charged and uncharged areas on said surface; (c)
contacting said surface with a liquid toner comprising a dispersion
of colorant particles in an organic liquid to create a toned image;
and (d) transferring said toned image to a substrate.
2. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a sulfolanyl group.
3. The electrophotographic imaging process of claim 2 wherein the
charge transport compound has a central nucleus of the formula:
33wherein L.sub.1 comprises an aryl group, and L.sub.2 and L.sub.3
are, each independently, selected from the group consisting of
hydrogen and hydrocarbons.
4. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a 4-(9H-fluoren-9-ylidene)benzyl group.
5. The electrophotographic imaging process of claim 4 wherein the
charge transport compound has a central nucleus of the formula:
34wherein L.sub.1 comprises an aryl group, and L.sub.2 and L.sub.3
are, each independently, selected from the group consisting of
hydrogen and hydrocarbons.
6. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a pyrrolyl group.
7. The electrophotographic imaging process of claim 6 wherein the
charge transport compound has a central nucleus of the formula:
35wherein L.sub.1 comprises an aryl group, and L.sub.2, L.sub.3 and
L.sub.4 are, each independently, selected from the group consisting
of hydrogen and hydrocarbons.
8. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a pyrazolyl group.
9. The electrophotographic imaging process of claim 8 wherein the
charge transport compound has a central nucleus of the formula:
36wherein L.sub.1 comprises an aryl group, and L.sub.2, L.sub.3 and
L.sub.4 are, each independently, selected from the group consisting
of hydrogen and hydrocarbons.
10. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a benzotriazolyl group.
11. The electrophotographic imaging process of claim 10 wherein the
charge transport compound has a central nucleus of the formula:
37wherein L.sub.1 comprises an aryl group, and L.sub.2, L.sub.3 and
L.sub.4 are, each independently, selected from the group consisting
of hydrogen and hydrocarbons.
12. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a stilbenyl group.
13. The electrophotographic imaging process of claim 12 wherein the
charge transport compound has a central nucleus of the formula:
38wherein L.sub.1 comprises an aryl group, and L.sub.2 and L.sub.3
are, each independently, selected from the group consisting of
hydrogen and hydrocarbons.
14. The electrophotographic imaging process of claim 1 wherein
R.sub.2 comprises a tetrazolyl group.
15. The electrophotographic imaging process of claim 14 wherein the
charge transport compound has a central nucleus of the formula:
39wherein L.sub.1 comprises an aryl group, and L.sub.2 and L.sub.3
are, each independently, selected from the group consisting of
hydrogen and hydrocarbons.
16. The electrophotographic imaging process of claim 1 wherein
R.sub.1 comprises hydrogen, an alkyl or an aryl and R.sub.2
comprises a sulfonylphenyl group.
17. The electrophotographic imaging process of claim 16 wherein the
charge transport compound has a central nucleus of the formula:
40wherein L.sub.1 comprises a hydrogen atom, an alkyl group, or an
aryl group, and L.sub.2 is selected from the group consisting of
hydrogen and hydrocarbons.
18. The electrophotographic imaging process of claim 1 wherein the
charge transport compound is a compound selected from the group
consisting of 41424344454647
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of copending
U.S. patent application Ser. No. 10/215,359, filed on Aug. 9, 2002,
now U.S. Pat. No. ______, which claims priority to U.S. Provisional
Patent Application Ser. Nos. 60/311,601, 60/314,055, 60/314,047,
60/317,086, 60/317,088, 60/323,782, 60/323,781, 60/325,716, and
60/330,381, all of which are incorporated herein by reference.
FIELD OF INVENTION
[0002] This invention relates to organophotoreceptors suitable for
use in electrophotography and, more specifically, to flexible
organophotoreceptors having novel charge transport compounds
comprising a group-substituted hydrazone.
BACKGROUND
[0003] In electrophotography, an organophotoreceptor in the form of
a plate, belt, disk, or drum having an electrically insulating
photoconductive element on an electrically conductive substrate is
imaged by first uniformly electrostatically charging the surface of
the photoconductive layer, and then exposing the charged surface to
a pattern of light. The light exposure selectively dissipates the
charge in the illuminated areas where light strikes the surface,
thereby forming a pattern of charged and uncharged areas (referred
to as latent image). A fine liquid or solid toner is then provided
in the vicinity of the latent image, and toner droplets or
particles deposit in either the charged or uncharged areas to
create a toned image on the surface of the photoconductive layer.
The resulting visible toner image can be transferred to a suitable
permanent or intermediate receiving surface such as paper, or the
photoconductive layer can operate as a permanent receptor for the
image. The imaging process can be repeated many times to overlay
images of distinct color components or effect shadow images, such
as overlaying images of distinct colors to form a full color final
image.
[0004] Both single layer and multilayer photoconductive elements
have been used commercially. In the single layer embodiment, a
charge transport material and charge generating material are
combined with a polymeric binder and then deposited on an
electrically conductive substrate. In the multilayer embodiment,
the charge transport material and charge generating material are
present in the element in separate layers, each of which materials
can optionally be combined with a polymeric binder and deposited on
the electrically conductive substrate. Two arrangements are
possible. In one arrangement (the "dual layer" two layer
arrangement), the charge generating layer is deposited on the
electrically conductive substrate and the charge transport layer is
deposited on top of the charge generating layer. In an alternate
arrangement (the "inverted dual layer" two layer arrangement), the
order of the charge transport layer and charge generating layer is
reversed.
[0005] In both the single and multilayer photoconductive elements,
the purpose of the charge generating material is to generate charge
carriers (i.e., holes or electrons) upon exposure to light. The
purpose of the charge transport material is to accept these charge
carriers and transport them through the charge transport layer in
order to discharge a surface charge on the photoconductive
element.
[0006] To produce high quality images, particularly after multiple
cycles, it is desirable for the charge transport material to form a
homogeneous solution with the polymeric binder and remain in
solution. In addition, it is desirable to maximize the amount of
charge which the charge transport material can accept (indicated by
a parameter known as the acceptance voltage or "V.sub.acc"), and to
minimize retention of that charge upon discharge (indicated by a
parameter known as the residual voltage or "V.sub.res").
[0007] There are many charge transport materials available for
electrophotography. The most common charge transport materials are
pyrazoline derivatives, fluorene derivatives, oxadiazole
derivatives, stilbene derivatives, hydrazone derivatives, carbazole
hydrazone derivatives, triphenylamine derivatives, julolidine
hydrazone derivatives, polyvinyl carbazole, polyvinyl pyrene, or
polyacenaphthylene. However, each of the above charge transport
materials suffers some disadvantages. There is always a need for
novel charge transport materials to meet the various requirements
of electrophotography applications.
SUMMARY OF THE INVENTION
[0008] An organophotoreceptor comprises a) a charge transport
compound having the formula 2
[0009] where R.sub.1 and R.sub.2 are selected so that R.sub.1 and
R.sub.2 form, with the included nitrogen atom, a group selected
from the group consisting of heterocyclic rings, aromatic rings,
and dinaphthylamine; or R.sub.1 comprises an aryl group and R.sub.2
comprises a group selected from the group consisting of sulfolanyl,
4-(9H-fluoren-9-ylidene)benzyl, pyrrolyl, pyrazolyl,
benzotriazolyl, stilbenyl, tetrazolyl; or R.sub.1 comprises
hydrogen, an alkyl group, or an aryl group and R.sub.2 comprises
sulfonylphenyl.
[0010] R.sub.3 is hydrogen, an alkyl group, an aryl group, a
heterocyclic group or a hydrocarbon group; and
[0011] Q is a 3-carbazole group;
[0012] (b) a charge generating compound; and
[0013] (c) an electrically conductive substrate.
[0014] In first embodiments, the charge transport compound has a
central nucleus of the formula: 3
[0015] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0016] In second embodiments, the charge transport compound has a
central nucleus of the formula: 4
[0017] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0018] In third embodiments, the charge transport compound has a
central nucleus of the formula: 5
[0019] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0020] In fourth embodiments, the charge transport compound has a
central nucleus of the formula: 6
[0021] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0022] In fifth embodiments, the charge transport compound has a
central nucleus of the formula: 7
[0023] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0024] In sixth embodiments, the charge transport compound has a
central nucleus of the formula: 8
[0025] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0026] In seventh embodiments, the charge transport compound has a
central nucleus of the formula: 9
[0027] wherein L.sub.1, L.sub.2, and L.sub.3 are independently
selected from hydrogen and hydrocarbons.
[0028] In eighth embodiments, the charge transport compound has a
central nucleus of the formula: 10
[0029] wherein L.sub.1 and L.sub.2 are independently selected from
hydrogen and hydrocarbons.
[0030] The organophotoreceptor may be provided in the form of a
plate, a flexible belt, a flexible disk, a sheet, a rigid drum, or
a sheet around a rigid or compliant drum. In one embodiment, the
organophotoreceptor includes: (a) a charge transport layer
comprising the charge transport compound and a polymeric binder;
(b) a charge generating layer comprising the charge generating
compound and a polymeric binder; and (c) the electrically
conductive substrate. The charge transport layer may be positioned
intermediate between the charge generating layer and the
electrically conductive substrate. Alternatively, the charge
generating layer may be positioned intermediate between the charge
transport layer and the electrically conductive substrate.
[0031] In a second aspect, the invention features an
electrophotographic imaging apparatus that includes (a) a plurality
of support rollers; and (b) the above-described organophotoreceptor
in the form of a flexible belt threaded around the support rollers.
The apparatus preferably further includes a liquid toner dispenser.
The method of electrophotographic imaging with photoreceptors
containing these novel charge transport compounds is also
described.
[0032] In a third aspect, the invention features an
electrophotographic imaging process that includes (a) applying an
electrical charge to a surface of the above-described
organophotoreceptor; (b) imagewise exposing the surface of the
organophotoreceptor to radiation to dissipate charge in selected
areas and thereby form a pattern of at least relatively charged and
uncharged areas on the surface; (c) contacting the surface with a
liquid toner that includes a dispersion of colorant particles in an
organic liquid to create a toned image; and (d) transferring the
toned image to a substrate.
[0033] In a fourth aspect, the invention features a novel charge
transport material having the above formula.
[0034] The invention provides novel charge transport materials for
organophotoreceptors featuring a combination of good mechanical and
electrostatic properties. These photoreceptors can be used
successfully with liquid toners to produce high quality images. The
high quality of the imaging system is maintained after repeated
cycling.
[0035] Other features and advantages of the invention will be
apparent from the following description of the preferred
embodiments thereof, and from the claims.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The invention features organophotoreceptors that include
novel charge transport compounds having the formula 11
[0037] where R.sub.1 and R.sub.2 are selected so that R.sub.1 and
R.sub.2 form, with the included nitrogen atom, a group selected
from the group consisting of heterocyclic rings, aromatic rings,
and dinaphthylamine; or R.sub.1 comprises an aryl group and R.sub.2
comprises a group selected from the group consisting of sulfolanyl,
4-(9H-fluoren-9-ylidene)benzyl, pyrrolyl, pyrazolyl,
benzotriazolyl, stilbenyl, tetrazolyl; or R.sub.1 comprises
hydrogen, an alkyl group, or an aryl group and R.sub.2 comprises
sulfonylphenyl;
[0038] R.sub.3 is hydrogen, an alkyl group, an aryl group, a
heterocyclic group or a hydrocarbon group; and
[0039] Q is a 3-carbazole group.
[0040] The variations described in groups R.sub.1 and R.sub.2 are a
range of variations in nitrogen substitution on active compounds
known in a variety of arts, such as the dye art, the photographic
sensitizer art, the photoinitiator art, and the like. Rather than
having a pair of distinct substituents (e.g., an alkyl groups, an
aryl groups, and heterocyclic groups), there may be a single chain
of a molecular entity having its alpha and omega ends bonded to the
nitrogen to form a cyclic group. In particular, 5-member, 6-member
and 7-member rings (with or without fused rings and substituents on
the rings) are useful in the practice of the invention and are
enabled by the disclosure in this application.
[0041] The charge transport compounds according to Formula (1) may
be prepared by the reaction of a group-substituted hydrazine and
the corresponding carbazole-3-carbaldehyde derivative in a molar
ratio of 1:1 to form the corresponding hydrazone compound by
refluxing the reactants in tetrahydrofuran (THF) for two hours.
[0042] The organophotoreceptor may be in the form of a plate, drum,
disk, sheet, or belt, with flexible belts being preferred. The
organophotoreceptor may include an electrically conductive
substrate and a photoconductive element in the form of a single
layer that includes both the charge transport compound and charge
generating compound in a polymeric binder. Preferably, however, the
organophotoreceptor includes an electrically conductive substrate
and a photoconductive element that is a bilayer construction
featuring a charge generating layer and a separate charge transport
layer. The charge generating layer may be located intermediate or
between the electrically conductive substrate and the charge
transport layer. Alternatively, the photoconductive element may be
an inverted construction in which the charge transport layer is
located intermediate or between the electrically conductive
substrate and the charge generating layer.
[0043] The electrically conductive substrate may be flexible, for
example in the form of a flexible web or a belt, or inflexible, for
example in the form of a drum. Typically, a flexible electrically
conductive substrate comprises an insulated substrate and a thin
layer of electrically conductive materials. The insulated substrate
may be paper or a film forming polymer such as polyester (e.g.,
polyethylene terepthalate, polyethylene naphthalate), polyimide,
polysulfone, polypropylene, nylon, polyester, polycarbonate,
polyvinyl resin, polyvinyl fluoride, polystyrene and the like.
Specific examples of supporting substrates included
polyethersulfone (STABAR.TM. S-100, available from ICI), polyvinyl
fluoride (TEDLAR.TM., available from E.I. DuPont de Nemours &
Company), polybisphenol-A polycarbonate (MACROFOL.TM., available
from Mobay Chemical Company) and amorphous polyethylene
terephthalate (MELINAR.TM., available from ICI Americas, Inc.). The
electrically conductive materials may be graphite, dispersed carbon
black, iodide, conductive polymers such as polypyroles and
CALGON.RTM. Conductive polymer 261 (commercially available from
Calgon Corporation, Inc., Pittsburgh, Pa.), metals such as
aluminum, titanium, chromium, brass, gold, copper, palladium,
nickel, or stainless steel, or metal oxide such as tin oxide or
indium oxide, metal coated layers, and conductive polymer coated
layers. Preferably, the electrically conductive material comprises
aluminum. Typically, the photoconductor substrate will have a
thickness adequate to provide the required mechanical stability.
For example, flexible web substrates generally have a thickness
from about 0.01 to about 1 mm, while drum substrates generally have
a thickness of from about 0.5 mm to about 2 mm.
[0044] In the description of chemical substituents, there are
certain practices common to the art that are reflected in the use
of language. Where the term `group` is used, that term allows for
the presence of further substitution on the named class of
materials, as long as the substitutent is still recognizable as
within the generic class. For example, where the term `alkyl group`
is used, that term would not only include unsubstituted liner,
branched and cyclic alkyls, such as methyl, ethyl, isopropyl,
tert-butyl, cyclohexyl, dodecyl and the like, but also
substitutents such as hydroxyethyl, cyanobutyl,
1,2,3-trichloropropane, and the like. Where the term alkyl moiety
is used, that term represents only an unsubstituted alkyl
hydrocarbon group, whether branched, straight chain, or cyclic.
Similarly, when referring to a cyclic compound by the terminology
"having a central nucleus of the formula," the compound or
substitutent cited will include any substitution that does not
substantively alter the chemical nature of the ring groups or other
salient bond structures in the formula (e.g., double bonds between
nitrogens, etc.). For example, the terminology having a central
nucleus of a phenyl ring would not include such alteration of the
ring wherein aromaticity is removed by saturation of double bonds
in the ring, while the addition of a long chain fatty acid group to
replace a hydrogen atom on the phenyl ring would be included. For
example, the terminology "having a central nucleus of the formula:
12
[0045] would include any compound having the cited ring structure
and the defined R.sub.1 (H) substituent and the defined R.sub.2
(C.sub.5H.sub.13) substituent. The naphthyl rings may have any
substituent that does not change the internal bond structure. The
phenyl rings on the hydrazone likewise may have any substituent
that does not alter the internal bond structure shown. The double
bond between the carbon and nitrogen atom also could not be removed
or converted to a single bond by additional substitution on the
carbon and nitrogen atoms. This modest breadth is required as it is
well known in the art to place substituents on such compounds in
such positions to affect physical properties such as spectral
absorbance, solubility, dispersibility, stability and the like. The
disclosure is intended to enable and disclose that those rings may
be so substituted, and the examples are not intended to limit the
disclosure to only such unsubstituted materials. By merely
providing the appropriate reagent, with substituents in the
appropriate positions, the substituted final product may be
provided in essentially the same chemical reaction, with only
modest variations in conditions and/or solvents selected to be
appropriate for those reagents and products.
[0046] Specific, non-limiting examples of suitable charge transport
compounds within the general structure of the present invention
have the following structures. 1314151617181920212223
[0047] The charge generating compound is a material which is
capable of absorbing light to generate charge carriers, such as a
dyestuff or pigment. Non-limiting examples of suitable charge
generating compounds include metal-free phthalocyanines (e.g.,
Sanyo Color Works, Ltd., CGM-X01), metal phthalocyanines such as
titanium phthalocyanine, copper phthalocyanine, oxytitanium
phthalocyanine (also referred to as titanyl oxyphthalocyanine, and
including any crystalline phase or mixtures of crystalline phases
that can act as a charge generating compound), hydroxygallium
phthalocyanine, squarylium dyes and pigments, hydroxy-substituted
squarylium pigments, perylimides, polynuclear quinones available
from Allied Chemical Corporation under the tradename INDOFAST.TM.
Double Scarlet, INDOFAST.TM. Violet Lake B, INDOFAST.TM. Brilliant
Scarlet and INDOFAST.TM. Orange, quinacridones available from
DuPont under the tradename MONASTRAL.TM. Red, MONASTRAL.TM. Violet
and MONASTRAL.TM. Red Y, naphthalene 1,4,5,8-tetracarboxylic acid
derived pigments including the perinones, tetrabenzoporphyrins and
tetranaphthaloporphyrins, indigo- and thioindigo dyes,
benzothioxanthene-derivatives, perylene 3,4,9,10-tetracarboxylic
acid derived pigments, polyazo-pigments including bisazo-, trisazo-
and tetrakisazo-pigments, polymethine dyes, dyes containing
quinazoline groups, tertiary amines, amorphous selenium, selenium
alloys such as selenium-tellurium, selenium-tellurium-arsenic and
selenium-arsenic, cadmium sulfoselenide, cadmiumselenide, cadmium
sulfide, and mixtures thereof. Preferably, the charge generating
compound is an oxytitanium phthalocyanine (e.g., any phase
thereof), hydroxygallium phthalocyanine or a combination
thereof.
[0048] Preferably, the charge generation layer comprises a binder
in an amount of from about 10 to about 90 weight percent and more
preferably in an amount of from about 20 to about 75 weight
percent, based on the weight of the charge generation layer.
[0049] The binder is capable of dispersing or dissolving the charge
transport compound (in the case of the charge transport layer) and
the charge generating compound (in the case of the charge
generating layer). Non-limiting examples of suitable binders for
both the charge generating layer and charge transport layer include
ethylenically unsaturated polymeric materials, such as
polystyrene-co-butadiene, acrylic polymers, modified acrylic
polymers, polyvinyl acetate, styrene-alkyd resins, soya-alkyl
resins, polyvinylchloride, polyvinylidene chloride,
polyacrylonitrile, polycarbonates, polyacrylic acid, polyacrylates,
polymethacrylates, styrene polymers, polyvinyl acetals (e.g.,
polyvinyl butyral), alkyd resins, polyamides, polyurethanes,
polyesters, polysulfones, polyethers, polyketones, phenoxy resins,
epoxy resins, silicone resins, polysiloxanes, poly(hydroxyether)
resins, polyhydroxystyrene resins, novolak, poly(phenylglycidyl
ether)-co-dicyclopentadiene, copolymers of monomers used in the
above-mentioned polymers, and combinations thereof. Polycarbonate
binders are particularly preferred. Examples of suitable
polycarbonate binders include polycarbonate A which is derived from
bisphenol-A, polycarbonate Z, which is derived from cyclohexylidene
bisphenol, polycarbonate C, which is derived from methylbisphenol
A, and polyestercarbonates.
[0050] The photoreceptor may include additional layers as well.
Such layers are well-known and include, for example, barrier
layers, release layers, adhesive layer, and sub-layer. The release
layer forms the uppermost layer of the photoconductor element with
the barrier layer sandwiched between the release layer and the
photoconductive element. The adhesive layer locates and improves
the adhesion between the barrier layer and the release layer. The
sub-layer is a charge blocking layer and locates between the
electrically conductive substrate and the photoconductive element.
The sub-layer may also improve the adhesion between the
electrically conductive substrate and the photoconductive
element.
[0051] Suitable barrier layers, where desired, include coatings
such as crosslinkable siloxanol-colloidal silica coating and
hydroxylated silsesquioxane-colloidal silica coating, and organic
binders such as polyvinyl alcohol, methyl vinyl ether/maleic
anhydride copolymer, casein, polyvinyl pyrrolidone, polyacrylic
acid, gelatin, starch, polyurethanes, polyimides, polyesters,
polyamides, polyvinyl acetate, polyvinyl chloride, polyvinylidene
chloride, polycarbonates, polyvinyl butyral, polyvinyl acetoacetal,
polyvinyl formal, polyacrylonitrile, polymethyl methacrylate,
polyacrylates, polyvinyl carbazoles, copolymers of monomers used in
the above-mentioned polymers, vinyl chloride/vinyl acetate/vinyl
alcohol terpolymers, vinyl chloride/vinyl acetate/maleic acid
terpolymers, ethylene/vinyl acetate copolymers, vinyl
chloride/vinylidene chloride copolymers, cellulose polymers, and
mixtures thereof. The above organic binders optionally may contain
small inorganic particles such as fumed silica, silica, titania,
alumina, zirconia, or a combination thereof. The typical particle
size is in the range of 0.001 to 0.5 micrometers, preferably 0.005
micrometers. A preferred barrier layer is a 1:1 mixture of methyl
cellulose and methyl vinyl ether/maleic anhydride copolymer with
glyoxal as a crosslinker.
[0052] The release layer topcoat may comprise any release layer
composition known in the art. Preferably, the release layer is a
fluorinated polymer, siloxane polymer, fluorosilicone polymer,
silane, polyethylene, polypropylene, polyacrylate, or a combination
thereof. More preferably, the release layers are crosslinked
silicone polymers.
[0053] Typical non-limiting examples of adhesive layers include
film forming polymers such as polyester, polyvinylbutyral,
polyvinylpyrolidone, polyurethane, polymethyl methacrylate,
poly(hydroxy amino ether) and the like. Preferably, the adhesive
layer is poly(hydroxy amino ether). If such layers are utilized,
they preferably have a dry thickness between about 0.01 micrometer
and about 5 micrometers.
[0054] Typical non-limiting examples of sub-layers include
polyvinylbutyral, organosilanes, hydrolyzable silanes, epoxy
resins, polyesters, polyamides, polyurethanes, silicones and the
like. Preferably, the sub-layer has a dry thickness between about
20 Angstroms and about 2,000 Angstroms.
[0055] The charge transport compounds, and photoreceptors including
these compounds, are suitable for use in an imaging process with
either dry or liquid toner development. Liquid toner development is
generally preferred because it offers the advantages of providing
higher resolution images and requiring lower energy for image
fixing compared to dry toners. Examples of useful liquid toners are
well-known. They typically include a colorant, a resin binder, a
charge director, and a carrier liquid. A preferred resin to pigment
ratio is 2:1 to 10:1, more preferably 4:1 to 8:1. Typically, the
colorant, resin, and the charge director form the toner
particles.
[0056] The invention will now be described further by way of the
following examples.
EXAMPLES
I. Synthetic Background
[0057] Examples of the synthesis of the subgeneric groups
hydrazones of the present invention are provided below. Although
the examples are separated by synthesis, the preparation of
intermediates and the actual synthetic steps are similar, showing
the generic nature of the characterization of these hydrazones. For
the most part, the structures differ with regard to the nature of
the ring group (heterocyclic, aromatic, or blended) shown in the
R.sub.2 position in the generic formula (I) shown for the class of
compounds of the invention.
[0058] All of the hydrazones fall within the generic definition of
a charge transport compound having the formula 24
[0059] where R.sub.1 and R.sub.2 are selected so that R.sub.1 and
R.sub.2 form, with the included nitrogen atom, a group selected
from the group consisting of dinaphthylamine; or R.sub.1 comprises
an aryl group and R.sub.2 comprises a group selected from the group
consisting of sulfolanyl, 4-(9H-fluoren-9-ylidene)benzyl, pyrrolyl,
pyrazolyl, benzotriazolyl, stilbenyl, tetrazolyl; or R.sub.1
comprises hydrogen, an alkyl group, or an aryl group and R.sub.2
comprises sulfonylphenyl.
[0060] R.sub.3 is hydrogen, an alkyl group, an aryl group, a
heterocyclic group or a hydrocarbon group; and
[0061] Q is a 3-carbazole group.
A. Synthesis Relating to DiNaphthalene Hydrazones
1,1-Dinaphthylhydrazine
[0062] 1,1-Dinaphthylhydrazine can be prepared according to the
procedure described in Journal of the General Chemistry (1964), 34,
136 by Staschkow et el., which is incorporated herein by
reference.
[0063] A suspension of 0.07 mole of the naphthyl nitrosamine in 750
ml of ether was cooled to 5-8.degree. C. and treated with 150 g of
zinc dust. 70 ml of acetic acid was then added drop wise with
stirring. To complete the reaction, 40 g of zinc dust was added.
The reaction mixture was heated and filtered from the sludge. The
mother liquor was washed with 10% sodium carbonate solution and
dried with solid KOH. The ether was distilled off to give the
crystalline hydrazines, which was crystallized from ethanol or
butanol.
Compound (2)
[0064] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
1,1-Dinaphthylhydrazine (2.86 g, 0.01 mole) in a molar ratio of 1
:1 is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (2) is
isolated and purified by recrystallization.
Compound (3)
[0065] Compound (3) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0066] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-penthyl-3-carbazolecarboxaldehyde.
[0067] 9-Penthyl-3-carbazolecarboxaldehyde or N-Pentyl-3-formyl
carbazole (2.65 g, 0.01 mole) and 1,1-Dinaphthylhydrazine (2.86 g,
0.01 mole) in a molar ratio of 1:1 is refluxed in tetrahydrofuran
(20 ml) for 16 hours with stirring. Upon removal of the solvent,
the crude Compound (3) is isolated and purified by
recrystallization.
Compound (4)
[0068] Compound (4) can be prepared by the procedure for Compound
(3) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (5)
[0069] Compound (5) can be prepared by the procedure for Compound
(2) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
Compound (6)
[0070] Compound (6) can be prepared by the procedure for Compound
(2) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-(9-methyl-9H-carbazol-3-yl)-1-propanone (commercially available
from Interbioscreen Ltd., P.O. Box 218, Moscow 121019, Russia; web:
www.ibscreen.com).
Compound (7)
[0071] Compound (7) can be prepared by the procedure for Compound
(2) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of 9-propyl-carbazole-3-carboxaldehyde
(commercially available from AslnEx, 6 Schukinskaya Street, Moscow
123182, Russia; web: www.asinex.com).
Compound (8)
[0072] Compound (8) can be prepared by the procedure for Compound
(2) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of 9-H-carbazole-3-carboxaldehyde
(commercially available from TimTec, Inc., Wilmington, Del.; web:
www.timtec.net).
Compound (9)
[0073] Compound (9) can be prepared by the procedure for Compound
(2) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
9-(phenylmethyl)-carbazole-3-carboxaldehyde (commercially available
from AslnEx, 6 Schukinskaya Street, Moscow 123182, Russia; web:
www.asinex.com).
Compound (10)
[0074] Compound (10) can be prepared by the procedure for Compound
(2) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of 9-methyl-carbazole-3-carboxaldehyde
(commercially available from TimTec, Inc., Wilmington, Del.; web:
www.timtec.net).
II. Organophotoreceptor Preparation Methods
[0075] Inverted dual layer organophotoreceptor can be prepared by
incorporating Compounds (2)-(50). A charge transport solution
containing 50 wt. % of one the compounds in Polycarbonate Z binder
can be prepared by combining a solution of 1.25 g of the compound
in 8.0 g of tetrahydrofuran with 1.25 g of Polycarbonate Z in 2.50
g of toluene. The charge transport solution is then knife-coated
onto a 3 mil (76 micrometer) thick aluminized polyethylene
terephthalate film (MELINEX.TM. 442 polyester film from Dupont
having a 1 ohm/square aluminum vapor coat) having a 0.3 micron
polyester resin sub-layer (VITEL.RTM. PE-2200 from Bostik,
Middletown, Mass.) and dried to form a charge transport layer
having a thickness of 9 micrometers.
[0076] A dispersion can be prepared by micronising 1.35 g of
oxytitanium phthalocyanine pigment (H.W. Sands Corp., Jupiter,
Fla.), 1.35 g of S-LEC B.TM. Bx-5 polyvinylbutryal resin (Sekisui
Chemical Co. Ltd.), 26 g of methyl ethyl ketone, and 13 g of
toluene using a horizontal sand mill operating in recirculation
mode for 8 hours. The resulting dispersion is then knife-coated
onto the charge transport layer and dried at 80.degree. C. for 10
minutes to form a charge generating layer having a thickness of
0.27 micrometer on the PET film.
III. Electrostatic Testing
[0077] Electrostatic testing of the inverted dual layer
organophotoreceptors prepared from the compounds can be performed
and recorded on a QEA PDT-2000 instrument at ambient temperature.
Charge-up is performed at 8 kV. Discharge is performed by exposing
the photoreceptor to a 780 nm-filtered tungsten light source down a
fiber optic cable. Each sample is exposed to 2 microjoules/cm.sup.2
of energy for 0.05 seconds; the total exposure intensity is 20
microwatts/cm.sup.2. After charge-up, the acceptance voltage
(V.sub.acc) is measured in volts. This value is recorded as
V.sub.acc after one cycle. Following this initial charge-up, a one
second dark decay followed before the sample is discharged with the
0.05 second light pulse of 2 microjoules/cm.sup.2 at 780 nm, one
second after which the decrease in voltage (Contrast) is measured
in volts. Then the charge on the sample is further reduced by an
eraser lamp. The final residual voltage (V.sub.res) on the sample
is measured in volts. V.sub.acc and V.sub.res are also measured
after a total of 1000 cycles. In general, it is desirable to
maximize V.sub.acc and to minimize V.sub.res.
Suppemental Examples
Preparation of N-Phenyl-N-sulfolan-3-ylhydrazine
[0078] The compound has been synthesized according to the following
procedure 25
[0079] Butadiene sulfone (0.5 mol, obtained from Aldrich chemicals,
Milwaukee, Wis.) and phenyl hydrazine (0.55 mol, 1.1 equiv.
obtained from Aldrich Chemicals, Milwaukee, Wis.) were stirred for
5-10 minutes, and then 40% aqueous KOH solution (0.005 mol, 0.01
equiv. obtained from Aldrich Chemicals, Milwaukee, Wis.) ) was
added. The mixture was heated at 60.degree. C. for 2 hours
whereupon a solid separated. After 10 hours at room temperature,
the solid was filtered, washed with excess of water and
recrystallized from methanol to give the product as white crystals;
yield 53%; mp119.9-121.5.degree. C.; .sup.1H-NMR and .sup.13C-NMR
spectra in CDCl.sub.3 were in full agreement with the
structure.
Preparation of 1-Aminopyrrole
[0080] 1-Aminopyrrole was synthesized in two steps from the
N-aminophthalamide (1) according to the following scheme. 26
[0081] Step one:--Preparation of
2-(1H-pyrrol-1-yl)-1H-isoindole-1,3(2H)-d-
ione:--N-aminophthalamide (1, 10 g, 62 mmol ; obtained from Aldrich
Chemicals; Milwaukee, Wis.) and 1,5-dimethoxytetrahydrofuran (2, 12
mL, 90 mmol; obtained from Aldrich Chemicals; Milwaukee, Wis. )
were refluxed in 100 mL of dry 1,4-dioxane for few minutes to form
a clear yellow solution. 5 N HCl (10 mL) was then added and
stirred. White precipitate started to appear after 15-20 minutes.
This solution with precipitate was allowed to stir for another 1
hour and was then cooled in an ice-water bath. The precipitate
formed were filtered and washed with 150 mL of dioxane/water (1/3),
and dried in air to give 3 as yellow prisms; yield 78%; mp
219-220.degree. C.; .sup.1H-NMR and .sup.13C-NMR were in full
agreement with the structure.
[0082] Step two:--Preparation of 1-aminopyrrole:--To a suspension
of 3 (103 g, 0.5 mol) in 500 mL methanol, 30 mL of hydrazine
hydrate (88%, w/v, obtained from Aldrich Chemicals, Milwaukee;
Wis.) was added. The suspension disappeared and the resulting
solution was heated to reflux. White solid was formed from the
clear solution. After 45 minutes of heating under reflux, the
reaction mixture was cooled to room temperature, and 15 mL of
acetic acid was added and stirred. The solid obtained was filtered
off and washed with methanol. The filtrate was collected and
concentrated to give white residue to which NaOH (2M, 100 mL) was
added to dissolve. This mixture was extracted with ether, dried
over MgSO.sub.4, and concentrated to give a product as yellow oil;
yield 40%; .sup.1H-NMR and .sup.13C-NMR spectra were in full
agreement with the structure of the compound.
4-Methylsulfonylphenylhydrazine hydrochloride
[0083] 27
[0084] Commercially available from Fisher Scientific USA,
Pittsburgh, Pa.
1,1'-(sulfonyldi-4-1-Phenylene)bis-hydrazine
[0085] 28
[0086] Commercially available from Vistas-M (Moscow, Russia)
Preparation of N-Pentyl-3-formyl carbazole
[0087] This material was prepared according to the following
procedure 29
[0088] Step one:--Preparation of N-Pentylcarbazole:--To a 1 liter
3-neck round bottom flask equipped with reflux condenser and
mechanical stirrer were added 250 g carbazole (1.5 mol; obtained
from Aldrich Chemicals; Milwaukee; Wis.), 241.7 g 1-bromopentane
(1.6 mol; obtained from Aldrich Chemicals; Milwaukee; Wis.), 17 g
benzyltriethyl ammonium chloride (0.075 mol ; obtained from Aldrich
Chemicals; Milwaukee; Wis.) and 1000 ml of toluene. The mixture was
stirred at room temperature for 0.5 hr., followed by the addition
of an aqueous solution of NaOH (prepared by dissolving 300 g of
NaOH in 300 g water). The mixture was refluxed for 5 hours and
cooled to room temperature. The organic phase was separated and
washed repeatedly with water until the pH of the washing water was
neutral. The organic phase was dried over Mg.sub.2SO.sub.4,
filtered, and evaporated to dryness to obtain 345 g of brown liquid
(97% yield). .sup.1H-NMR and IR spectra were in agreement with the
structure of N-heptylcarbazole. H-NMR spectrum in CDCl3 was also in
full agreement with the structure.
[0089] Step two:--preparation of N-Pentyl-3-formylcarbazole: To a
1-liter, 3-neck round bottom flask (RBF) equipped with mechanical
stirrer, thermometer, and addition funnel, was added 600 ml DMF.
The contents were cooled in a salt/ice bath. When the temperature
inside the flask reached 0.degree. C., 154 ml of POCl.sub.3 (1.65
mol; obtained from Aldrich Chemicals; Milwaukee; Wis.) was slowly
added. During the addition of POCl.sub.3, the temperature inside
the flask was not allowed to rise above 5.degree. C. After the
addition of POCl.sub.3 was completed, the reaction mixture was
allowed to warm to room temperature. 345 g of N-heptylcarbazole
(1.50 mole; prepared in step one) was then added and the flask was
heated to 90.degree. C. for 2 hours using a heating mantle. The
reaction mixture was cooled to room temperature and the solution
was added slowly to a 4.5 liter beaker containing a solution of 820
g sodium acetate dissolved in 2 liters of water. The beaker was
cooled in an ice bath and stirred for 3 hr. The brownish solid
obtained was filtered and washed repeatedly with water, followed by
a small amount of ethanol (50 ml). The resulting product was
recrystallized once from toluene using activated charcoal and dried
under vacuum in an oven heated at 70.degree. C. for 6 hours to
obtain 330 g (83% yield) of N-heptyl-3-diformyl-carbazo- le.
.sup.1H-NMR spectra confirmed the presence of
N-heptyl-3-diformyl-carb- azole.
B. Synthesis Relating to the Sulfolanyl Hydrazones
N-Phenyl-N-sulfolan-3-ylhydrazine
[0090] N-Phenyl-N-sulfolan-3-ylhydrazine can be prepared according
to the procedure described in Great Britain Patent No. 1,047,525 by
Mason, which is incorporated herein by reference. To a mixture of
0.5 mole of butadiene sulfone (commercially available from Aldrich,
Milwaukee, Wis.) and 0.55 mole of phenylhydrazine (commercially
available from Aldrich, Milwaukee, Wis.) was added 0.005 mole 40%
aqueous potassium hydroxide solution. The mixture was kept for 2
hours at 60.degree. C. whereupon a solid separated. After 10 hours
the solid was filtered off to give
N-phenyl-N-sulfolan-3-ylhydrazine (I) (93%) having a melting point
of 119-20.degree. C. (MeOH).
N-(2-Naphthyl)-N-sulfolan-3-ylhydrazine
[0091] N-(2-Naphthyl)-N-sulfolan-3-ylhydrazine can be prepared
according to the procedure for N-phenyl-N-sulfolan-3-ylhydrazine
except phenylhydrazine is replaced with 2-naphthylhydrazine.
2-Naphthylhydrazine can be prepared according to the procedure
described in Chinese Patent No. 1,175,571 by Su et el., which is
incorporated herein by reference. 2-Naphthylhydrazine can also be
prepared by neutralizing 2-naphthylhydrazine hydrochloride with
potassium hydroxide, which is commercially available from Apin
Chemical Ltd. (UK), 82C Milton Park, Abingdon, Oxon, OX14 4RY,
United Kingdom. (Web: http://www.apinchemicals.- com.)
[0092] To a mixture of 0.5 mole of butadiene sulfone (commercially
available from Aldrich, Milwaukee, Wis.) and 0.55 mole of
2-naphthylhydrazine is added 0.005 mole 40% aqueous potassium
hydroxide solution. The mixture is kept for 16 hours at 60.degree.
C. N-(2-Naphthyl)-N-sulfolan-3-ylhydrazine is isolated and
purified.
Synthesis of N-Phenyl-N-sulfolan-3-ylhydrazone of
9-Ethyl-3-carbazolecarbo- xaldehyde (Compound 11)
[0093] 30
Compound (11)
[0094] To a 500 ml 3-neck RBF equipped with reflux condenser and
mechanical stirrer, were added 22.32 g of
9-Ethyl-3-Carbazolecarboxaldehy- de (0.1 mole, obtained from
Aldrich Chemical Co., P.O. Box 2060, Milwaukee, Wis. 53201 and used
as received) and 24.86 g of N-phenyl-N-sulfolan-3-ylhydrazine (0.11
mole, as prepared in experimental section (A) in 300 ml of toluene
in the presence to 5 drops of concentrated sulfuiric acid. The
solution was refluxed for 2 hours. TLC (Thin layer chromatography)
showed the disappearance of the starting materials and the
appearance of the product. The solution was cooled to room
temperature, and then decanted to remove a very small amount of
dark solid at the bottom of the flask. The toluene solution was
extracted several times with 100 ml of water until the pH of the
water was neutral. The toluene solution was dried over magnesium
sulfate and evaporated until approximately 100 ml remained and was
then cooled in an ice bath to precipitate the product which was
collected and dried and recrystalyzed 3 times from toluene with
activated charcoal. In the third recrystalyzation, we used also
silica gel in addition to the activated charcoal. Obtained: H-NMR
spectrum in CDCl3 in agreement with the structure
Synthesis of Compound 12, N-Phenyl-N-sulfolan-3-ylhydrazone of
9-Pentyl-3-carbazolecarboxaldehyde
[0095] 31
Compound (12)
[0096] To a 500 ml 3-neck RBF equipped with reflux condenser and
mechanical stirrer, were added 22.32 g of
9-Pentyl-3-Carbazolecarboxaldeh- yde (0.1 mole, Prepared as in
experimental section (B)) and 24.86 g of
N-phenyl-N-sulfolan-3-ylhydrazine (0.11 mole) (prepared in section
(A)) in 300 ml of toluene in the presence to 5 drops of
concentrated Sulfiric acid. The solution was refluxed for 2 hours.
TLC showed the disappearance of the starting materials and the
appearance of the product. The solution was cooled to room
temperature, decanted to remove a very small amount of dark solid
at the bottom of the flask. The toluene solution was extracted
several times with 100 ml of water until the pH of the water was
neutral. The toluene solution was dried over magnesium sulfate and
evaporated till dryness. Obtained was a gummy liquid which
solidified upon standing at RT. The product was collected and dried
and recrystalyzed 3 times from Toluene with activated charcoal. In
the third recrystalyzation, we used also silica gel in addition to
the activated charcoal. Obtained: H-NMR spectrum in CDCl3 in
agreement with the structure
Compound (13)
[0097] Compound (13) can be prepared by the procedure for Compound
(12) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (14)
[0098] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-(2-naphthyl)-N-sulfolan-3-- ylhydrazine (2.76 g, 0.01 mole) is
refluxed in tetrahydrofuran (20 ml) for 16 hours with stirring.
Upon removal of the solvent, the crude Compound (14) is isolated
and purified by recrystallization.
Compound (15)
[0099] Compound (15) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0100] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
[0101] 9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-(2-naphthyl)-N-sulfolan-3-- ylhydrazine (2.76 g, 0.01 mole) is
refluxed in tetrahydrofuran (20 ml) for 16 hours with stirring.
Upon removal of the solvent, the crude Compound (15) is isolated
and purified by recrystallization.
Compound (16)
[0102] Compound (16) can be prepared by the procedure for Compound
(15) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich Chemicals,
Milwaukee, Wis.).
Compound (17)
[0103] Compound (17) can be prepared by the procedure for Compound
(11) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
C. Synthesis Relating to the Carbazole Pyrrolyl Hydrazones
N-Pyrrol-2-yl-N-phenylhydrazine
[0104] N-Pyrrol-2-yl-N-phenylhydrazine can be prepared according to
the procedure described in Japanese Patent No. 05148210 by Myamoto,
which is incorporated herein by reference.
Compound (18)
[0105] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-pyrrol-2-yl-N-phenylhydraz- ine (1.73 g, 0.01 mole) is refluxed
in tetrahydrofuran (20 ml) for 16 hours with stirring. Upon removal
of the solvent, the crude Compound (18) is isolated and purified by
recrystallization.
Compound (19)
[0106] Compound (19) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0107] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
[0108] 9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-pyrrol-2-yl-N-phenylhydraz- ine (1.73 g, 0.01 mole) is refluxed
in tetrahydrofuran (20 ml) for 16 hours with stirring. Upon removal
of the solvent, the crude Compound (19) is isolated and purified by
recrystallization.
Compound (20)
[0109] Compound (20) can be prepared by the procedure for Compound
(19) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (21)
[0110] Compound (21) can be prepared by the procedure for Compound
(19) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
D. Synthesis Relating to Carbazole
N-stilbenyl-N-phenylhydrazones
N-(4-Stilbenyl)-N-phenylhydrazine
[0111] N-(4-Stilbenyl)-N-phenylhydrazine can be prepared according
to the procedure described in Zh. Org. Khim. (1967), 3(9), 1605-3
by Matevosyan et el., which is incorporated herein by reference. To
a mixture of phenylhydrazine (97 g, 0.9 mole, commercially
available from Aldrich, Milwaukee, Wis.) and p-chlorostilbene (21.4
g, 0.1 mole, commercially available from Spectrum Quality Products,
Inc., Gardena, Calif.; Web: www.spectrumchemical.com) heated to
boiling temperature, sodium was slowly added until there was no
more discharge of red coloration. After boiling for some time the
mixture was dissolved in 1750 ml of ethanol and cooled to
-15.degree. C. The precipitated product was recrystallized to give
28% of N-(4-stilbenyl)-N-phenylhydrazine.
Compound (22)
[0112] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-(4-stilbenyl)-N-phenylhydr- azine (2.86 g, 0.01 mole) is refluxed
in tetrahydrofuran (20 ml) for 16 hours with stirring. Upon removal
of the solvent, the crude Compound (22) is isolated and purified by
recrystallization.
Compound (23)
[0113] Compound (23) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0114] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
[0115] 9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-(4-stilbenyl)-N-phenylhydr- azine (2.86 g, 0.01 mole) is refluxed
in tetrahydrofuran (20 ml) for 16 hours with stirring. Upon removal
of the solvent, the crude Compound (23) is isolated and purified by
recrystallization.
Compound (24)
[0116] Compound (24) can be prepared by the procedure for Compound
(23) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (25)
[0117] Compound (25) can be prepared by the procedure for Compound
(22) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
Compound (26)
[0118] Compound (26) can be prepared according to the following
procedure. To a mixture of phenylhydrazine (19.4 g, 0.18 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
alpha-(4-chlorophenyl)-3,4-d- imethoxycinnamonitrile (6.00 g, 0.02
mole, CAS #65952-64-9; commercially available from Aldrich,
Milwaukee, Wis.) heated to boiling temperature, sodium was slowly
added until there was no more discharge of red coloration. After
boiling for some time the mixture was dissolved in 350 ml of
ethanol and cooled to -15.degree. C. The precipitated product was
recrystallized to give
N-(3,4-dimethoxycinnamonitrile-alpha-phenyl)-N-phe- nylhydrazine.
9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole, commercially
available from Aldrich, Milwaukee, Wis.) and
N-(3,4-dimethoxycinnamonitrile-alpha-phenyl)-N-phenylhydrazine
(3.71 g, 0.01 mole) is refluxed in tetrahydrofuran (20 ml) for 16
hours with stirring. Upon removal of the solvent, the crude
Compound (26) is isolated and purified by recrystallization.
Compound (27)
[0119] Compound (27) can be prepared by the procedure for Compound
(26) except 0.02 mole of
alpha-(4-chlorophenyl)-3,4-dimethoxycinnamonitrile is replaced with
0.02 mole of 4-chloro-alpha-(p-tolyl)-cinnamonitrile (CAS
#84434-79-7, commercially available from Aldrich, Milwaukee,
Wis.).
E. Synthesis Relating to Carbazole
N-[4-(9H-fluoren-9-ylidene)benzyl]-N-ph- enylhydrazones
[0120] N-4-[(9H-fluoren-9-ylidene)benzyl] -N-phenylhydrazine
N-4-[(9H-fluoren-9-ylidene)benzyl]-N-phenylhydrazine can be
prepared according to the procedure similar to that described in
Zh. Org. Khim. (1967), 3(9), 1605-3 by Matevosyan et el., which is
incorporated herein by reference. To a mixture of phenylhydrazine
(97 g, 0.9 mole, commercially available from Aldrich, Milwaukee,
Wis.) and p-9-(4-chlorobenzylidene)fluorene (28.9 g, 0.1 mole,
commercially available from Aldrich, Milwaukee, Wis.) heated to
boiling temperature, sodium was slowly added until there was no
more discharge of red coloration. After boiling for some time the
mixture was dissolved in 1750 ml of ethanol and cooled to
-15.degree. C. The precipitated product was recrystallized to give
N-4-[(9H-fluoren-9-ylidene)benzyl]-N-phenylhydrazi- ne.
Compound (28)
[0121] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-4-[(9H-fluoren-9-ylidene)b- enzyl]-N-phenylhydrazine (3.6 g, 0.01
mole) is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (28) is
isolated and purified by recrystallization.
Compound (29)
[0122] Compound (29) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0123] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
[0124] 9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-4-[(9H-fluoren-9-ylidene)b- enzyl]-N-phenylhydrazine (3.6 g, 0.01
mole) is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (29) is
isolated and purified by recrystallization.
Compound (30)
[0125] Compound (30) can be prepared by the procedure for Compound
(29) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (3 1)
[0126] Compound (31) can be prepared by the procedure for Compound
(28) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
F. Synthesis Relating to Carbazolecarboxaldehyde
N-benzotriazolyl-N-phenyl- hydrazones
N-(5-Benzotriazolyl)-N-phenylhydrazine
[0127] N-(5-benzotriazolyl)-N-phenylhydrazine can be prepared
according to the procedure described below. To a mixture of
phenylhydrazine (97 g, 0.9 mole, commercially available from
Aldrich, Milwaukee, Wis.) and 5-chlorobenzotriazole (15.4 g, 0.1
mole, commercially available from Aldrich, Milwaukee, Wis.) heated
to boiling temperature, sodium is slowly added until there is no
more discharge of red coloration. After boiling for some time the
mixture is cooled to room temperature. The product is isolated and
purified.
Compound (32)
[0128] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
N-(5-benzotriazolyl)-N-pheny- lhydrazine (2.25 g, 0.01 mole) is
refluxed in tetrahydrofuran (20 ml) for 16 hours with stirring.
Upon removal of the solvent, the crude Compound (32) is isolated
and purified by recrystallization.
Compound (33)
[0129] Compound (33) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0130] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole, commercially
available from Aldrich, Milwaukee, Wis.) and
N-(5-benzotriazolyl)-N-pheny- lhydrazine (2.25 g, 0.01 mole) is
refluxed in tetrahydrofuran (20 ml) for 16 hours with stirring.
Upon removal of the solvent, the crude Compound (33) is isolated
and purified by recrystallization.
Compound (34)
[0131] Compound (34) can be prepared by the procedure for Compound
(33) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (35)
[0132] Compound (35) can be prepared by the procedure for Compound
(32) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
l-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
G. Synthesis Relating to Carbazolecarboxaldehyde
Tetrazolylhydrazones
1-Phenyl-1-(1-benzyl-1H-tetrazol-5-yl)hydrazine
[0133] 1-Phenyl-1-(1-benzyl-1H-tetrazol-5-yl)hydrazine can be
prepared according to the procedure described in Tetrahedron
(1983), 39(15), 2599-608 by Atherton et el., which is incorporated
herein by reference.
Compound (36)
[0134] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
1-phenyl-1-(1-benzyl-1H-tetr- azol-5-yl)hydrazine (2.66 g, 0.01
mole) is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (36) is
isolated and purified by recrystallization.
Compound (37)
[0135] Compound (37) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0136] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
[0137] 9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
1-phenyl-1-(1-benzyl-1H-tetr- azol-5-yl)hydrazine (2.66 g, 0.01
mole) is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (37) is
isolated and purified by recrystallization.
Compound (38)
[0138] Compound (38) can be prepared by the procedure for Compound
(37) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (39)
[0139] Compound (39) can be prepared by the procedure for Compound
(37) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
H. Synthesis Relating to Carbazolecarboxaldehyde
pyrazolylhydrazones
5-Methyl-1-Phenyl-3-(1-Phenylhydrazino)-Pyrazole
[0140] 5-Methyl-i-phenyl-3-(1-phenylhydrazino)-pyrazole can be
prepared according to the procedure described in J. Chem. Soc. C
(1971), (12), 2314-17 by Boyd et el., which is incorporated herein
by reference.
Compound (40)
[0141] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
5-methyl-1-phenyl-3-(1-pheny- lhydrazino)-pyrazole (2.64 g, 0.01
mole) is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (40) is
isolated and purified by recrystallization.
Compound (41)
[0142] Compound (41) can be prepared according to the following
procedure. Carbazole (16.7 g, 0.1 mol, commercially available from
Aldrich, Milwaukee, Wis.), 1-bromopentane (15.1 g, 0.1 mol,
commercially available from Aldrich, Milwaukee, Wis.), and
benzyltriethyl ammonium chloride (1.7 g) are dissolved in
tetrahydrofuran (60 mL) and a concentrated solution of sodium
hydroxide (17 g) in water (17 mL) is added. The mixture is heated
at reflux with strong mechanical stirring for 4 hours, then cooled
to room temperature and poured into an excess of water. The solid
that precipitated is filtered off and the tetrahydrofuran layer is
dried (MgSO.sub.4) and concentrated to dryness. The combined
organic solids were recrystallized to form 9-pentylcarbazole.
[0143] Dimethylformamide (100 mL) is stirred and cooled in an ice
bath while phosphorus oxychloride (35 mL, 58 g, 0.38 mol) is
gradually added. 9-Pentylcarbazole (52 g, 0.22 mol) is introduced
and the resulting mixture is heated on a steam bath with stirring
for 1.5 hours. The entire mixture is cooled and added to water (200
mL) and the crude product is filtered off at the pump, washed with
water (200 mL). The crude product is recrystallized to form
9-pentyl-3-carbazolecarboxaldehyde.
[0144] 9-Pentyl-3-carbazolecarboxaldehyde (2.65 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
5-methyl-1-phenyl-3-(1-pheny- lhydrazino)-pyrazole (2.64 g, 0.01
mole) is refluxed in tetrahydrofuran (20 ml) for 16 hours with
stirring. Upon removal of the solvent, the crude Compound (41) is
isolated and purified by recrystallization.
Compound (42)
[0145] Compound (42) can be prepared by the procedure for Compound
(42) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (43)
[0146] Compound (43) can be prepared by the procedure for Compound
(41) except 0.01 mole of 9-Ethyl-3-carbazolecarboxaldehyde is
replaced with 0.01 mole of
1-[9-(3-methylbutyl)-9H-carbazol-3-yl]-ethanone (commercially
available from Interbioscreen Ltd., 121019 Moscow, P.O. Box 218,
Moscow, Russia; web: www.ibscreen.com).
Compound (44)
[0147] Compound (44) can be prepared by the procedure for Compound
(40) except 5-methyl-1-phenyl-3-(1-phenylhydrazino)-pyrazole (2.64
g, 0.01 mole) is replaced with 0.1 mole of
1-phenylhydrazino-pyrazole.
Compound (45)
[0148] Compound (45) can be prepared by the procedure for Compound
(41) except 5-methyl-1-phenyl-3-(1-phenylhydrazino)-pyrazole (2.64
g, 0.01 mole) is replaced with 0.1 mole of
1-phenylhydrazino-pyrazole.
I. Synthesis Relating to Carbazolecarboxaldehyde
Sulfonylphenylhydrazones
Compound (46)
[0149] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
4-methylsulfonylphenylhydraz- ine (1.86 g, 0.01 mole, commercially
available from Fisher Scientific USA, Pittsburgh, Pa.) is refluxed
in tetrahydrofuran (20 ml) for 16 hours with stirring. Upon removal
of the solvent, the crude Compound (46) is isolated and purified by
recrystallization.
Compound (47)
[0150] 9-Ethyl-3-carbazolecarboxaldehyde (2.23 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) and
4-(methylsulfonyl)-2-nitroph- enylhydrazine (2.31 g, 0.01 mole,
commercially available from Aldrich, Milwaukee, Wis.) is refluxed
in tetrahydrofuran (20 ml) for 16 hours with stirring. Upon removal
of the solvent, the crude Compound (47) is isolated and purified by
recrystallization.
Compound (48)
[0151] To a 500 ml 3-neck RPF equipped with mechanical stirrer and
reflux condenser were added 7.69 g of
9-Pentyl-3-Carbazolecarboxaldehyde (0.03 mole, prepared in
experimental section (B)) and 100 ml of tetrahydrofuran (THF). To a
separate beaker were added 7.3 g of 4-Methylsulfonylphenylhyd-
razine hydrochloride (0.033 mole, obtained from Fisher Scientific
USA, Pittsburgh, Pa.), 70 ml of THF, and then a solution of 5.52 g
of K2CO3 in 25 ml of THF were added. This solution was added to the
aldehyde solution and refluxed for 4 hours in the presence of few
drops of concentrated sulfuric acid. TLC showed the disappearance
of the starting materials and the appearance of the product. After
the solution was cooled to RT, it was evaporated till dryness to
obtain a yellow solid which was recrystalyzed 3 times from THF with
activated charcoal used in all recrystalizations, and silica gel
was added only to the third recrystalization. Obtained was 14 g
(56% yield). H-NMR spectrum in CDCl3 was in agreement with the
structure.
Compound (49)
[0152] Compound (49) can be prepared by the procedure for Compound
(46) except 0.1 mole of 1-bromopentane is replaced with 0.1 mole of
1-bromodecane (commercially available from Aldrich, Milwaukee,
Wis.).
Compound (50)
[0153] To a 100 ml RBF equipped with reflux condenser and magnetic
stirrer were added, 16.6 g of 9-Pentyl-3-Carbazolecarboxaldehyde
(0.061 mole, prepared as in experimental section B) and 50 ml of
Ethanol were heated until all solid went into solution. 5 g of
1-aminopyrrole (prepared in experimental section A) was added and
the solution was refluxed for five hours in the presence of few
drops of glacial acetic acid. The solution was cooled to RT, then
evaporated to dryness to obtain 10 g of the product (50% yield)
H-NMR spectrum in CDCl3 was in agreement with the structure.
IV. Ionization Potential Protocol
[0154] Samples for ionization potential (Ip) measurements were
prepared by dissolving Compounds 11, 12, 48, 50 independently in
tetrahydrofuran. Each solution was hand-coated on an aluminized
polyester substrate that was precision coated with a
methylcellulose-based adhesion sub-layer to form a charge transport
material (CTM) layer. The role of this sub-layer was to improve
adhesion of the CTM layer, to retard crystallization of CTM, and to
eliminate the electron photoemission from the Al layer through
possible CTM layer defects. No photoemission was detected from the
Al through the sub-layer at illumination with up to 6.4 eV quanta
energy light. In addition, the adhesion sub-layer was conductive
enough to avoid charge accumulation on it during measurement. The
thickness of both the sub-layer and CTM layer was .about.0.4 .mu.m.
No binder material was used with CTM in the preparation of the
samples for Ip measurements.
[0155] The ionization potential was measured by the electron
photoemission in air method similar to that described in
"Ionization Potential of Organic Pigment Film by Atmospheric
Photoelectron Emission Analysis", Electrophotography, 28, Nr. 4, p.
364. (1989) by E. Miyamoto, Y. Yamaguchi, and M. Yokoyama, which is
hereby incorporated by reference. The samples were illuminated with
monochromatic light from the quartz monochromator with a deuterium
lamp source. The power of the incident light beam was
2.multidot.5.10.sup.-8 W. The negative voltage of -300 V was
supplied to the sample substrate. The counter-electrode with the
4.5.times.15 mm.sup.2 slit for illumination was placed at 8 mm
distance from the sample surface. The counter-electrode was
connected to the input of the BK2-16 type electrometer, working in
the open impute regime, for the photocurrent measurement. A
10.sup.-15-10.sup.-12 amp photocurrent was flowing in the circuit
under illumination. The photocurrent, I, was strongly dependent on
the incident light photon energy hv. The I.sup.0.5=f(hv) dependence
was plotted. Usually the dependence of the square root of
photocurrent on incident light quanta energy is well described by
linear relationship near the threshold [see references "Ionization
Potential of Organic Pigment Film by Atmospheric Photoelectron
Emission Analysis", Electrophotography, 28, Nr. 4, p. 364. (1989)
by E. Miyamoto, Y. Yamaguchi, and M. Yokoyama; and "Photoemission
in Solids", Topics in Applied Physics, 26, 1-103. (1978) by M.
Cordona and L. Ley]. The linear part of this dependence was
extrapolated to the hv axis and Ip value was determined as the
photon energy at the interception point. The ionization potential
measurement has an error of .+-.0.03 eV. The ionization potential
data are listed in Table 1.
V. Hole Mobility
[0156] Samples for charge carrier mobility measurements were
prepared by dissolving Compounds 11, 12, 48, 50 independently in
tetrahydrofuran with a binder to form 10% solid solutions. The
binder was polycarbonate Z 200 (commercially obtained from
Mitsubishi Engineering Plastics, White Plains, N.Y.). The
sample/binder ratio was 4:6 or 5:5. Each solution was coated on an
aluminized polyester substrate to form a charge transport material
(CTM) layer. The thickness of the CTM layer varied in the range of
5-10 .mu.m.
[0157] The hole drift mobility was measured by a time of flight
technique as described in "The discharge kinetics of negatively
charged Se electrophotographic layers," Lithuanian Journal of
Physics, 6, p. 569-576 (1966) by E. Montrimas, V. Gaidelis, and A.
Paiera, which is hereby incorporated by reference. Positive corona
charging created electric field inside the CTM layer. The charge
carriers were generated at the layer surface by illumination with
pulses of nitrogen laser (pulse duration was 2 ns, wavelength 337
nm). The layer surface potential decreased as a result of pulse
illumination was up to 1-5% of initial potential before
illumination. The capacitance probe that was connected to the wide
frequency band electrometer measured the speed of the surface
potential dU/dt. The transit time t.sub.t was determined by the
change (kink) in the curve of the dU/dt transient in linear or
double logarithmic scale. The drift mobility was calculated by the
formula .mu.=d.sup.2/U.sub.0.multidot.t.sub.t, where d is the layer
thickness and U.sub.0 is the surface potential at the moment of
illumination.
[0158] Mobility values at electric field strength, E, of
6.4.multidot.10.sup.5 V/cm are given in the Table 1. The mobility
field dependencies may be approximated by the function
.mu..about.e.sup..alpha.{square root}{square root over (E)}
[0159] where .alpha. is parameter characterizing mobility field
dependence. The value of the parameter .alpha. is also given in
Table 1.
1 TABLE 1 Mobility I.sub.p Compound (cm.sup.2/Vs) .alpha. (eV) 12
1.6 .times. 10.sup.-8 0.0063 5.55 48 1.7 .times. 10.sup.-8 0.0065
-- 50 No signal -- 5.74 11 1.2 .times. 10.sup.-8 -- 5.62
[0160] It is well understood in the art that variations in
substitution, variations in additives, variations in processes and
apparatus of use, and conditions and proportions may be varied to
achieve variations in performance within the control of the
ordinarily skilled artisan. The examples and the disclosure
represent a generic disclosure intended to include those
variations, and the claims represent a descriptions of the
invention including those variations. Those variations and all
generic embodiments of the invention are intended to be included
within the following claims.
* * * * *
References