Poly(quinone) and preparation and use of same

An alkyl group-substituted poly(quinone) useful as a material for an electrochromic device and an n-type semiconductor device, includes a repeating unit, has a polymerization degree (n) of not less than 20, includes a .pi.-conjugated system, and contains, as the repeating unit, bivalent residues of dihalogenated aromatic compounds of alkyl group-substituted quinones in which the alkyl group has from 1-8 carbon atoms and the bivalent residues are obtained by removing halogen atoms at two locations. A method for producing the alkyl group-substituted poly(quinone) includes dehalogenating and polycondensing to polymerize a dihalogenated aromatic compound of an alkyl group-substituted quinone by removing halogen atoms at two locations in the presence of a zero-valent nickel compound, whereby the zero-valent nickel compound withdraws halogens from the dihalogenated aromatic compound and causes coupling between aromatic groups thereof. Alternatively, the polymerization may be accomplished by electrochemical reduction in the presence of a divalent nickel compound.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a novel alkyl group-substituted 
poly(quinone), a method for manufacturing the same and applications 
thereof. The polymer according to the present invention has bivalent 
residues of dihalogenated aromatic compounds of alkyl group-substituted 
quinones as the repeating unit, which residues having been obtained by 
removing halogen atoms from the dihalogenated aromatic compounds at two 
locations. The polymer also has a .pi.-conjugated system extending along 
the principal chain, and is converted into conductive material by 
electrochemical doping. Furthermore, the polymer of the present invention 
is stable in the air and soluble to various organic solvents. The present 
invention also relates to materials for electrochromic devices and n-type 
semiconductor devices, which utilize the alkyl group-substituted 
poly(quinone) to show two-stepped color changes at a rather small 
reduction voltage. 
DESCRIPTION OF THE RELATED ART 
Recently, .pi.-conjugated polymers are appreciated as materials that 
perform electrolytic and optical functions. In these polymers having a 
.pi.-conjugated system, .pi. electrons in the system extend in one 
dimension along the principal chain of the polymer. Accordingly, such 
polymers have electrical conductivity and high photosensitivity. Also, 
since these .pi.-conjugated polymers generate, in its principle chain, 
positively charged carriers when oxidized, and negatively charged carriers 
when reduced, they can have high electrical conductivity. In this 
connection, the redox reactions are accompanied by color changes of the 
.pi.-conjugated polymers, and therefore, these compounds can be used as 
materials for an electrochromic device. This redox function can further be 
applied to a production of a modified electrode. 
As these conductive polymers having the .pi.-conjugated system extending 
along the principal chain, various compounds as shown by the following 
chemical formulae are known. For the simplicity, they are hereinafter 
collectively referred to as Formula (1). 
##STR1## 
On the other hand, quinones are known as one of typical .pi.-conjugated 
molecules which have a redox power. Due to the unique redox power of 
quinones, conductive polymers comprising quinone units as its repeating 
unit have excellent properties which the other .pi.-conjugated conductive 
polymers cannot have. For example, poly-p-phenylene, polythiophene and 
polypyridine shown in the above Formula (1) require more negative 
potential than about -2.0V vs. Ag/Ag+ to be electrochemically reduced 
while exhibiting color change (electrochromism). Poly(quinone), however, 
requires much less negative potential such as about -1.3V vs. Ag/Ag+to 
exhibit such color change caused by the electrochemical reduction. In 
addition, different from those of the other .pi.-conjugated polymers, the 
color change of the poly(quinone) is two-stepped one, and therefore, the 
poly(quinone) can have a unique property as a material for a display 
element. Polyacethylene is not chemically stable, and also there is 
difficulty in confirming color changes caused by electrochemical redox 
reaction due to its blackish color. With respect to polypyrrole, it is 
difficult to electrochemically reduce this polymer. 
As described above, poly(quinone)s have advantages such that they undergo 
electrochemical reduction reaction at a rather small negative potential of 
about -1.0V vs. Ag/Ag+, more specifically at -1.3V vs. Ag/Ag+, while being 
accompanied by a unique two-stepped color change. However, most of the 
known poly(quinone)s also have disadvantages such as insolubility to 
organic solvents, infusibility and the like. Due to these disadvantages, 
there has not been found any effective processing method for these 
conventional poly(quinone)s. Accordingly, it is difficult to mold and give 
a predetermined shape to the conventional poly(quinone)s, and thus, only 
limited applications have been found for these polymers and the unique 
functions thereof have not been utilized effectively. 
Furthermore, although the known poly(quinone) can easily become a n-type 
conductor through reduction, it is difficult for them to be formed into a 
predetermined shape such as a film due to their insolubility to solvents. 
This also has greatly restricted applications of these polymers. 
SUMMARY OF THE INVENTION 
Considering these background arts, the inventors of the present invention 
have been searched for a novel conductive polymer comprising repeating 
quinone units, which has an improved solubility to common solvents. In 
this connection, the inventors have investigated to introduce an alkyl 
substitution group into an aromatic ring of poly(quinone) to improve the 
solubility of the polymer to the organic solvents. 
Accordingly, it is a primary object of the present invention to provide a 
novel alkyl group-substituted poly(quinone) comprising repeating quinone 
units, which has a sufficiently large molecular weight, an excellent 
heat-resistivity and improved solubility to various organic solvents, and 
undergo a two-stepped electrochemical reduction at a rather small 
potential, while being accompanied by two-stepped color change. 
To attain the above-mentioned object, there is provided according to the 
present invention, an alkyl group-substituted poly(quinone) having a 
polymerization degree (n) of not less than 20, and comprising, as the 
repeating unit, bivalent residues of dihalogenated aromatic compounds of 
alkyl group-substituted quinones, which bivalent residues being obtained 
by removing halogen atoms at two locations. 
The present invention also provides a method for producing an alkyl 
group-substituted poly(quinone) comprising dehalogenating dihalogenated 
aromatic compounds of alkyl group-substituted quinones by removing halogen 
atoms at two locations, and polymerizing the dehalogenated aromatic 
compounds, in the presence of a nickel compound. 
Since the poly(quinone) of the present invention has an alkyl substitution 
group, the polymer has an improved solubility to common organic solvents, 
and by utilizing an appropriate organic solution thereof, the polymer can 
be easily formed into a predetermined shape such as fibers, films and the 
like. Furthermore, since the polymer of the present invention comprises 
quinone units, which exhibit the above-explained unique redox behavior, as 
the repeating unit, the polymer can be used as a conductive material such 
as n-type conductor, material for batteries, material for electrochromic 
devices, and material for electronic devices such as transistors or 
diodes, by also making use of its improved solubility to various solvents.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention will be explained in detail below. 
According to the first aspect of the present invention, there is provided 
an alkyl group-substituted poly(quinone) having a polymerization degree 
(n) of not less than 20, and comprising, as the repeating unit, bivalent 
residues of dihalogenated aromatic compounds of alkyl group-substituted 
quinones, which bivalent residues being obtained by removing halogen atoms 
at two locations. 
As examples of the alkyl group-substituted poly(quinone) according to the 
present invention, mention may be made to polymers having, as the 
repeating unit, an alkyl group-substituted benzoquinone, an alkyl 
group-substituted naphthoquinone, an alkyl group-substituted anthraquinone 
or one of their derivatives, namely to those shown by the following 
chemical formulae. For the simplicity, the following formulae are 
hereinafter collectively referred to as Formula (2). 
##STR2## 
(wherein R, R' and R" respectively represent an alkyl group). 
The above-described polymers can be obtained by the following process. 
First, a hydrogen atom of a corresponding quinone is substituted with an 
alkyl group to obtain each alkyl group-substituted quinone shown by the 
following formulae. For the simplicity, the following formulae are 
hereinafter collectively referred to as Formula (3). 
##STR3## 
(wherein R represents an alkyl group). Next, hydrogen atoms of such alkyl 
group-substituted quinones are substituted with halogen atoms at two 
locations to attain such alkyl group-substituted dihalogenated aromatic 
compounds as shown by the following formulae. For the simplicity, the 
following formulae are hereinafter collectively referred to as Formula 
(4). perform functions as a conductive polymer effectively. Accordingly, 
the position at which one alkyl group-substituted quinone is combined to 
another is preferably such a place that the resulting polymer could have a 
.pi.-conjugated system, which extends along the principal chain. 
Also, the poly(quinone) according to the present invention may preferably 
have a solubility to N-methylpyrrolidone in an amount of 50 mg per 10 ml 
or more. The alkyl group-substituted poly(quinone) of the present 
invention is soluble to various solvents such as chloroform, methylene 
chloride, N-methylpyrrolidone, toluene, benzene, tetrahydrofuran and the 
like. For instance, 50 mg or more of this polymer is soluble in 10 ml of 
N-methylpyrrolidone. When the solubility of the polymer is less than 50 
mg, moldability thereof is too poor to obtain a sufficiently strong film. 
The more preferred amount of solubility is 80-500 mg. When the polymer has 
a solubility of not less than 80 mg, viscosity of the solution used for 
preparing films increases significantly, thereby making the resulting 
films quite strong. On the other hand, a solubility of 500 mg may be the 
upper limit for producing industrially competitive films in the light of 
cost. 
With respect to the alkyl substitution group (R) of the quinones used as 
the monomer for preparing the 
##STR4## 
(wherein R represents an alkyl group and X represents a halogen atom). 
Then, the alkyl group-substituted dihalogenated aromatic compounds are 
reacted with a zero-valent nickel compound to attain the aimed alkyl 
group-substituted poly(quinone)s. 
The poly(quinone) according to the present invention may preferably have a 
.pi.-conjugated system extending along the principal chain. When it does 
not contain such a .pi.-conjugated system, the polymer cannot polymer 
according to the present invention, there is no limitation on the number 
of carbon atoms, and its examples may include methyl group, ethyl group, 
propyl group, butyl group, pentyl group, hexyl group, octyl group and the 
like. However, it may be preferable for the alkyl substitution group of 
the dihalogenated aromatic compounds of quinones to have 1-4 carbon atoms. 
Once alkyl groups such as methyl groups are introduced into a 
poly(quinone), even in a case where only one alkyl group is introduced, 
the large intermolecular force of the poly(quinone) is weakened by a 
steric hindrance of the alkyl group, thereby significantly increasing the 
solubility of the polymer. Accordingly, an alkyl group-substituted 
poly(quinone) wherein the alkyl substitution group has only one carbon 
atom can attain the aim of the present invention. The more carbon atoms 
the substituting alkyl group includes, the more improved solubility the 
resulting polymer has. However, in the light of easiness of the industrial 
synthesis, it is preferable to introduce an alkyl group having 1-4 carbon 
atoms. 
Since the poly(quinone) of the invention contains an alkyl substitution 
group, the polymer has a sufficiently large molecular weight of 20,000 or 
more. 
Incidentally, the position at which one alkyl group-substituted quinone is 
combined to another, the position at which an alkyl substitution group is 
introduced, and the number of alkyl substitution groups to be introduced 
are not restricted as long as the resulting polymer could have a 
.pi.-conjugated system extending along the principal chain. In the case 
where two or more alkyl groups are introduced into a repeating quinone 
unit as shown in Formula (2), they may be consisted of the same group (ex. 
plural methyl groups) or different groups (ex. methyl group and dodecyl 
group) as long as they all belong to the alkyl group. 
The polymer according to the present invention has a polymerization degree 
(n) of not less than 20. When (n) is less than 20, the poly(quinone) may 
sometimes lack substantial functions as a polymer such as being 
sufficiently strong when formed into a film or the like. Preferably, the 
polymer of the invention may have a polymerization degree (n) of 100 or 
more. With such a high polymerization degree, the viscosity of solution, 
which is used when the polymer is formed into a film, is significantly 
increased, thereby making the resulting film quite strong. The inventors 
have prepared a poly(quinone) having a polymerization degree (n) of about 
260 according to the invention through a method described below, and 
confirmed the excellent properties and the applicability of the polymer in 
experiments described below. As a matter of course, the preparation and 
the application of the polymer having the polymerization degree of more 
than 260 may be expected. 
Examples of quinones applicable as a monomer in the present invention may 
include o-benzoquinone, p-benzoquinone, 1,2-naphthoquinone, 
1,4-naphthoquinone, anthraquinone and the like. From the industrial point 
of view, anthraquinone is most preferable among them because it can be 
acquired at a low cost and easily synthesized into a dihalogenated alkyl 
derivative, which is used as a material for the polymer of the present 
invention. 
According to the second aspect of the present invention, there is provided 
a method for producing an alkyl group-substituted poly(quinone) comprising 
dehalogenating dihalogenated aromatic compounds of alkyl group-substituted 
quinones by removing halogen atoms at two locations, and polymerizing the 
dehalogenated compounds in the presence of a nickel compound. 
The dehalogenation of a dihalogenated aromatic compound may be conducted by 
reacting the dihalogenated aromatic compound with a substance selected 
from a group consisting of a metal capable of dehalogenating the 
dihalogenated aromatic compound and a compound containing such a metal in 
the presence of a nickel compound. 
The alkyl group-substituted poly(quinone) according to the present 
invention may be obtained by reacting a dihalogenated alkylquinone as 
shown by Formula (4) with an equimolar amount or excess of a zero-valent 
nickel compound in an organic solvent for dehalogenation. A preferable 
reaction temperature range is 30.degree.-100.degree. C., and the reaction 
completes within about 10-100 hours. As the organic solvent, for example, 
N,N-dimethylformamide, acetonitrile, toluene, tetrahydrofuran or the like 
can be employed. 
The zero-valent nickel compound withdraws halogens from halogenated 
aromatic compounds and causes a coupling reaction between the aromatic 
groups [an example can be seen in "Synthesis", p.736 (1984)]. This 
reaction is represented by the following Formula (5): 
EQU Ar-X+Ar'-X+NiL.sub.m .fwdarw.Ar-Ar'+NiX.sub.2 L.sub.m (5) 
(wherein Ar and Ar' respectively represent an aromatic group, X represents 
a halogen atom, L represents a neutral ligand and hence NiLm represents a 
zero-valent nickel compound). 
Accordingly, if an aromatic compound having two halogens in the molecule, 
such as dihalogenated alkyl-quinone, is reacted with an equimolar or 
excess of a zero-valent nickel compound, the polymer of the present 
invention can be obtained by the dehalogenation polycondensation reaction 
shown in the following Formulae (6) and (7): 
##STR5## 
represents dihalogenated alkylquinone, R represents an alkyl group and X 
represents a halogen atom). 
In the above-described reaction, zero-valent nickel compounds synthesized 
in a homogeneous reaction system immediately before the polymerization 
reaction can be used directly, so to speak, in situ. Alternatively, 
preliminarily synthesized and isolated ones can be used. Such a 
zero-valent nickel compound is, for example, a nickel complex produced by 
a reduction reaction or a ligand interchange reaction in the presence of a 
neutral ligand. As a typical example of the neutral ligand, mention may be 
made of nitrogen-containing ligands including 1,5-cyclooctadiene, 
2,2'-bipyridine, tertiary phosphines including triphenylphosphine and the 
like. 
The poly(quinone)s shown in the above Formula (2) can also be obtained by 
another process, wherein the dihalogenated alkylquinone shown in Formula 
(4) is dehalogenated through an electrochemical reduction reaction which 
is conducted in the presence of a transition metal compound such as 
divalent nickel compound. The polymer of the present invention may be 
obtained by still another process, wherein the dihalogenated alkylquinone 
is dehalogenated by a chemical reduction reaction with a reducing metal 
such as zinc conducted in the presence of a transition metal compound such 
as divalent nickel compound. For example, when a divalent nickel compound 
is electrochemically reduced in an electrolytic cell, a zero-valent nickel 
compound is produced by the reaction shown in the following Formula (8): 
EQU [Ni.sup.II L.sub.m ].sup.2+ +2e.fwdarw.Ni.sup.0 L.sub.m (8) 
Accordingly, when an aromatic compound having two halogens in the molecule, 
for instance, a dihalogenated alkylquinone is electrochemically reduced in 
the presence of a nickel compound, the polymer shown in Formula (2) can be 
obtained according to the reaction shown in Formula (8) and the consequent 
reactions shown in the following Formulae (9)-(11), wherein the Ni.sup.0 
Lm, which has been produced in the reaction system is involved. 
##STR6## 
represents dihalogenated alkylquinone, R represents an alkyl group and X 
represents a halogen atom). 
The electrolysis may generally be conducted under the following conditions: 
namely, polar solvent such as N,N-dimethylformamide and acetonitrile is 
used as the solvent, a salt such as tetraethylammonium perchlorate and 
tetraethylammonium tetrafluoroborate are dissolved as a supporting 
electrolytic salt to prepare an electrolyte, and platinum electrodes, ITO 
transparent electrodes or graphite electrodes are employed as the 
electrodes. There may be dissolved 1,4-dichloro-2-methylanthraquinone and 
divalent nickel complex in the electrolyte and electrochemical reduction 
is conducted at a reduction potential of the divalent nickel complex, for 
example, at -1.7V vs. Ag/Ag+ in the case of tris(2,2'-bipyridine) nickel 
salt. 
A bivalent nickel compound can be reduced to a zero-valent one through the 
chemical reduction reaction with use of a reducing metal such as zinc as 
well as the electrochemical reduction reaction shown in the above Formula 
(8). In the case of the chemical reduction, the reducing metal performs 
the function of dehalogenating the dihalogenated alkylquinone to produce 
poly(alkylquinone) and the bivalent nickel compound functions as a 
catalyst. 
As described above, a zero-valent nickel compound may preferably be used as 
a metal compound having dehalogenating power in the method for producing 
alkyl group-substituted poly(quinone) according to the present invention. 
Further, a ligand in such a zero-valent nickel compound is preferably a 
nitrogen-containing ligand such as 1,5-cyclooctadiene and 2,2'-bipyridine, 
or a tertiary phosphine such as triphenylphosphine. 
Due to the excellent properties of the alkyl group-substituted 
poly(quinone) according to the present invention, the poly(quinone) can be 
formed into not only powders but also fibers and films by using an 
appropriate organic solvent. In addition, the polymer of the present 
invention can be reduced with use of a reducing agent or by chemical or 
electrochemical doping, and utilized as materials for batteries, materials 
for electrochromic devices, materials for electronic devices such as 
transistors or diodes, and conductive materials such as n-type conductors. 
As described before, the alkyl group-substituted poly(quinone) according to 
the present invention is a .pi.-conjugated polymer which undergoes a 
unique two-stepped electrochemical reduction at a rather small negative 
potential of about -1.0V vs. Ag/Ag+, more specifically at -1.3V vs. 
Ag/Ag+, while being accompanied by a color change. Further, since the 
polymer has an excellent solubility to common organic solvents, a solution 
thereof has a viscosity which is enough to form a sufficiently strong 
films thereof. Accordingly, the polymer can be suitably utilized as a 
material for electrochromic devices and a material for n-type 
semiconductor devices. 
Therefore, according to the third aspect of the present invention, there is 
provided a material for electrochromic devices comprising an alkyl 
group-substituted poly(quinone) having a polymerization degree (n) of not 
less than 20, and comprising, as the repeating unit, bivalent residues of 
dihalogenated aromatic compounds of alkyl group-substituted quinones, 
which bivalent residues being obtained by removing halogen atoms at two 
locations. 
Furthermore, according to the fourth aspect of the present invention, there 
is provided a material for n-type semiconductor devices comprising an 
alkyl group-substituted poly(quinone) having a polymerization degree (n) 
of not less than 20, and comprising, as the repeating unit, bivalent 
residues of dihalogenated aromatic compounds of alkyl group-substituted 
quinones, which bivalent residues being obtained by removing halogen atoms 
at two locations. 
The present invention will be hereinafter explained in further detail by 
way of the following examples. 
EXAMPLE 1 
Synthesis of Poly(2-methylanthraquinone-1,4-diyl) 
Under inert gas, 0.303 g of bis(1,5-cyclooctadiene) nickel complex 
(Ni(cod)2) (1.1 mmol) was added by 14 cm.sup.3 of N,N-dimethylformamide 
(DMF), 0.104 cm.sup.3 of 1,5-cyclooctadiene (cod) (0.85mmol) and 0.172 g 
of 2,2'-bipyridine (bpy) (1.1 mmol) in this order, and the mixture was 
stirred until the color thereof changed to purple. To this mixture was 
added, as the monomer of the aimed polymer, 14 cm.sup.3 of DMF solution of 
1,4-dichloro-2-methylanthraquinone (1,4-Cl.sub.2 -MeAQ) (0.25 g, 1.1 
mmol). After stirring at a temperature of 60.degree. C. for 48 hours, the 
reaction solution was poured into diluent hydrochloric acid and there was 
produced an yellow powder. The thus-obtained precipitate powder was washed 
twice with diluent hydrochloric acid, once with methanol, three times with 
warm aqueous solution of sodium ethylenediaminetetraacetic acid (EDTA), 
once with warm water, and once again with methanol. It was then dissolved 
in chloroform to be precipitated again, and the obtained precipitate was 
vacuum-dried by heating, thereby obtaining a deep yellow powder. The yield 
of the polymer was 89%. 
The analytical data of this polymer were C: 81.82%; H: 3.64%; Ci: 0%, and 
they almost agreed with the calculated values of C: 82.66%; H: 3.36%; Cl: 
0.00%. 
In the infrared absorption spectrum (KBr) of this polymer, there were 
observed absorption peaks at 3050 cm.sup.-1 which is ascribed to the C--H 
stretching vibration, at 2950 cm.sup.-1 which is ascribed to the C--H 
stretching vibration, at 1665 cm.sup.-1 which is ascribed to the C.dbd.O 
stretching vibration, at 1590 and 1526 cm.sup.-1 which are respectively 
ascribed to the C.dbd.C ring stretching vibration, at 1303 and 1247 
cm.sup.-1 which are respectively ascribed to the C--CO--C stretching and 
deformation vibration, and at 796-628 cm.sup.-1 which is ascribed to the 
C--H out-of-plane deformation vibration. 
In the .sup.1 H-NMR spectrum of this polymer in CDCl.sub.3 (90 MHz), there 
were observed peaks at .delta.=2.1, 2.3 and 2.6 ppm (which is assigned to 
3H and CH.sub.3) and at 7.5-8 ppm (which is assigned to 5H and others). 
The area ratio of these peaks was about 3:5. In the .sup.13 C-NMR spectrum 
of this polymer in CDCl.sub.3 (67.9 MHz), there were observed peaks at 
.delta.=21 ppm (which is assigned to CH.sub.3), at .delta.=126 ppm (which 
is assigned to C5 and C8), at 135 ppm (which is assigned to others), at 
.delta.=145 ppm (which is assigned to C1, C2 and C4) and at .delta.=180 
ppm (which is assigned to C9 and C10). 
The data obtained by the element analysis, infrared absorption spectrum, 
and NMR spectra support that the polymer has the following structure. 
##STR7## 
(wherein n represents a polymerization degree). 
The polymer had a weight-average molecular weight of 57,000 (polymerization 
degree: 255) as determined by light scattering method in chloroform 
solution. The intrinsic viscosity of the polymer was measured as 0.43 
dLg.sup.-1. The ultraviolet-visible absorption spectrum of the polymer in 
chloroform solution had an absorption peak at 375 nm, which had been 
shifted toward a longer wavelength from that of the structure unit 
thereof, namely that of 2-methylanthraquinone at 329.8 nm. Moreover, the 
polymer showed a high thermal stability. As a result of thermogravimetric 
analysis under nitrogen, weight decrease was observed to start at about 
300.degree. C. and the weight loss at 900.degree. C. was about 40%. The 
obtained polymer was soluble to chloroform, methylene chloride and 
N-methylpyrrolidone in an amount of 100 mg/10 ml or more, to toluene and 
benzene in an amount of about 80 mg/10 ml, and to tetrahydrofuran in an 
amount of about 50 mg/10 ml. 
COMATIVE EXAMPLE 1 
Synthesis of Poly(anthraquinone-1,4-diyl) 
Under inert gas, 0.36 g of bis(1,5-cyclooctadiene) nickel complex 
(Ni(cod).sub.2) (1.3 mmol) was added by 14 cm.sup.3 of 
N,N-dimethylformamide (DMF), 0.135 cm.sup.3 of 1,5-cyclooctadiene (cod) 
(1.1 mmol) and 0.203 g of 2,2'-bipyridine (bpy) (1.3 mmol) in this order, 
and the mixture was stirred until the color thereof changed to purple. To 
this mixture was added, as the monomer of the aimed polymer, 14 cm.sup.3 
of DMF solution of 1,4-dichloroanthraquinone (1,4-Cl.sub.2 -AQ) (0.30 g, 
1.1 mmol). After stirring at a temperature of 60.degree. C. for 48 hours, 
the reaction solution was poured into diluent hydrochloric acid and there 
was produced an yellow powder. The thus-obtained precipitate powder was 
washed twice with diluent hydrochloric acid, once with toluene, three 
times with warm aqueous solution of sodium ethylenediaminetetraacetic acid 
(EDTA), once with warm water, and once again with toluene. It was then 
vacuum-dried by heating to obtain an yellow powder. The yield of the 
polymer was 80%. Incidentally, the portion which was soluble to chloroform 
was refined through precipitation with use of methanol. 
The analytical data of this polymer were C: 81.55%; H: 2.91%; Ci: 0%, and 
they almost agreed with the calculated values of C: 80.36%; H: 3.81%; Ci: 
0.00%. 
In the infrared absorption spectrum (KBr) of this polymer, there were 
observed absorption peaks at 3050 cm.sup.-1 which is ascribed to the C--H 
stretching vibration, at 1667 cm.sup.-1 which is ascribed to the C.dbd.O 
stretching vibration, at 1590 cm.sup.-1 which is ascribed to the C.dbd.C 
ring stretching vibration, at 1323 and 1247 cm.sup.-1 which are 
respectively ascribed to the C--CO--C stretching and deformation 
vibration, and at 844-724 cm.sup.31 1 which is ascribed to the C--H 
out-of-plane deformation vibration. 
In the .sup.1 H-NMR spectrum of this polymer in CDCl.sub.3 (90 MHz), there 
was observed a peak at .delta.=7.5-8.5 ppm (m). In the solid-state .sup.13 
C-NMR spectrum of this polymer (270 MHz), there were observed peaks at 
.delta.=126 ppm (which is assigned to C5 and C8), at .delta.=135 ppm 
(which is assigned to others), at .delta.=145 ppm (which is assigned to C1 
and C4) and at .delta.=185 ppm (which is assigned to C9 and C10). 
The data obtained by the element analysis, infrared absorption spectrum, 
and NMR spectra support that the polymer has the following structure. 
##STR8## 
(wherein n represents a polymerization degree). 
The ultraviolet-visible absorption spectrum of this polymer in chloroform 
solution had an absorption peak at 369 nm, which had been shifted toward a 
longer wavelength from that of the structure unit thereof, namely that of 
anthraquinone at 327 nm. Moreover, the polymer showed a high thermal 
stability. As a result of thermogravimetric analysis under nitrogen, 
weight decrease was observed to start at about 300.degree. C. and the 
weight loss at 900.degree. C. was about 40%. The obtained polymer showed 
such a poor solubility as about 5 mg per 10 ml to chloroform, methylene 
chloride and N-methylpyrrolidone. Due to this poor solubility, it was 
impossible for this polymer to be measured .sup.13 C-NMR spectrum in 
solution. 
COMATIVE EXAMPLE 2 
Synthesis of Poly(anthraquinone-1,5-diyl) 
Under inert gas, 0.36 g of bis(1,5-cyclooctadiene) nickel complex 
(Ni(cod).sub.2) (1.3 mmol) was added by 14 cm.sup.3 of 
N,N-dimethylformamide (DMF), 0.135 cm.sup.3 of 1,5-cyclooctadiene (cod) 
(1.1 mmol) and 0.203 g of 2,2'-bipyridine (bpy) (1.3 mmol) in this order, 
and the mixture was stirred until the color thereof changed to purple. To 
this mixture was added, as the monomer of the aimed polymer, 14 cm.sup.3 
of DMF solution of 1,5-dichloroanthraquinone (1,5-Cl.sub.2 -AQ) (0.30 g, 
1.1 mmol). After stirring at a temperature of 60.degree. C. for 48 hours, 
the reaction solution was poured into diluent hydrochloric acid and there 
was produced an yellow powder. The thus-obtained precipitate powder was 
washed twice with diluent hydrochloric acid, once with toluene, three 
times with warm aqueous solution of sodium ethylenediaminetetraacetic acid 
(EDTA), once with warm water, and once again with toluene. It was then 
vacuum-dried by heating to obtain an yellow powder. The yield of the 
polymer was 90%. 
In the infrared absorption spectrum (KBr) of this polymer, there were 
observed absorption peaks at 3050 cm.sup.-1 which is ascribed to the C--H 
stretching vibration, at 1669 cm.sup.-1 which is ascribed to the C.dbd.O 
stretching vibration, at 1578 cm.sup.-1 which is ascribed to the C.dbd.C 
ring stretching vibration, at 1319 cm.sup.-1 and 1266 cm.sup.-1 which are 
respectively ascribed to the C--CO--C stretching and deformation 
vibration, and at 814-624 cm.sup.-1 which is ascribed to the C--H 
out-of-plane deformation vibration. 
In the solid-state .sup.13 C-NMR spectrum of this polymer (270 MHz), there 
were observed peaks at .delta.=126 ppm (which is assigned to C4 and C8), 
at .delta.=135 ppm (which is assigned to others), at .delta.=145 ppm 
(which is assigned to C1 and C5) and at .delta.=185 ppm (which is assigned 
to C9 and C10). 
The data obtained by the infrared absorption spectrum and NMR spectrum 
support that the polymer has the following structure. 
##STR9## 
(wherein n represents a polymerization degree). 
The thus-obtained poly(anthraquinone-1,5-diyl) was substantially insoluble 
to chloroform, methylene chloride, N-methylpyrrolidone, toluene, benzene 
and tetrahydrofuran. 
COMATIVE EXAMPLE 3 
Synthesis of Poly(1,4-naphthoquinone-5,8-diyl) 
Under inert gas, 0.44 g of bis(1,5cyclooctadiene) nickel complex 
(Ni(cod).sub.2) (1.6 mmol) was added by 14 cm.sup.3 of 
N,N-dimethylformamide (DMF), 0.144 cm.sup.3 of 1,5-cyclooctadiene (cod) 
(1.3 mmol) and 0.248 g of 2,2'-bipyridine (bpy) (1.6 mmol) in this order, 
and the mixture was stirred until the color thereof changed to purple. To 
this mixture was added, as the monomer of the aimed polymer, 14 cm.sup.3 
of DMF solution of 5,8-dichloro-1,4-naphthoquinone (0.30 g, 1.3mmol). 
After stirring at a temperature of 60.degree. C. for 48 hours, the 
reaction solution was poured into diluent hydrochloric acid and there was 
produced a brown powder. The thus-obtained precipitate powder was washed 
twice with diluent hydrochloric acid, once with toluene, three times with 
warm aqueous solution of sodium ethylene-diaminetetraacetic acid (EDTA), 
once with warm water, and once again with toluene. It was then 
vacuum-dried by heating to obtain a deep brown powder. The yield of the 
polymer was 75%. 
In the infrared absorption spectrum (KBr) of this polymer, there were 
observed absorption peaks at 3050 cm.sup.-1 which is ascribed to the C--H 
stretching vibration, at 1657 cm.sup.-1 which is ascribed to the C.dbd.O 
stretching vibration, at 1600-1540 cm.sup.-1 which is ascribed to the 
C.dbd.C ring stretching vibration, at 1324 and 1245 cm.sup.-1 which are 
respectively ascribed to the C--CO--C stretching and deformation 
vibration, and at 850 cm.sup.-1 which is ascribed to the C--H out-of-plane 
deformation vibration. 
In the .sup.1 H-NMR spectrum of this polymer in CD.sub.3 -SO-CD.sub.3 (90 
MHz), there were observed peaks at .delta.=6.9 ppm (which is assigned to 
br, 2H, C2 and C3-H) and at .delta.=7.6 ppm (which is assigned to br, 2H, 
C6 and C7-H), and the area ratio of these peaks was about 2:2. In the 
solid-state 13C-NMR spectrum of this polymer (270 MHz), there were 
observed peaks at .delta.=136.5 ppm (which is assigned to others) and at 
.delta.=185.5 ppm (which is assigned to C1 and C4). 
The data obtained by infrared absorption spectrum and NMR spectra support 
that the polymer has the following structure. 
##STR10## 
(wherein n represents a polymerization degree). 
The thus-obtained poly(1,4-naphthoquinone-5,8-diyl) showed a poor 
solubility of about 5 mg in 10 ml of N-methylpyrrolidone. 
EXAMPLE 2 
A chloroform solution of the poly(2-methylanthraquinone-1,4-diyl) obtained 
in Example 1 was applied onto a platinum plate and chloroform was removed 
to prepare a film of the polymer. With respect to this polymer film, 
cyclic voltammogram was measured in an anhydrous acetonitrile solution 
containing 0.1 mol.sup.-1 of (C.sub.2 H.sub.5).sub.4 NClO.sub.4 was at a 
scan rate of 20 mVS.sup.-1 at room temperature. As a result, it was found 
in the polymer that a cation was doped (n-type doping) at about -1.38 and 
-1.69V vs. Ag/Ag+ in two-stepped manner, and dedoped in reverse scanning 
at about -1.38 and -1.69V vs. Ag/Ag+ in the same manner. In the case of 
doping, the color of the polymer film changed from yellow to red, and then 
to deep red in two-stepped manner. In the case of dedoping, a reverse 
discoloration was observed. The results are shown in Table 1. These doping 
and dedoping processes were repeated with no observable deformation of the 
film. 
As described above, the polymer according to the present invention is 
capable of being electrochemically reduced, namely undergoing an 
electrochemical n-type doping, and the polymer exhibits electrochromic 
properties at the time of doping. Accordingly, the polymer of the present 
invention is electrochemically active and conductive, and therefore, 
usable as an electrode material for n-type semiconductor device and a 
material for electrochromic device. 
On the other hand, similar phenomenon was observed in 
poly(anthraquinone-1,4-diyl) obtained in Comparative Example 1. In the 
cyclic voltammogram of the film of this polymer, two pairs of 
reduction-oxidation peaks were also observed at about -1.30V and -1.62V 
vs. Ag/Ag+, and the redox reactions were observed to be accompanied by 
color changes of the film between yellow and red, and between red and deep 
red, respectively. However, the film of poly(anthraquinone-1,4-diyl) 
formed on a platinum plate was quite brittle when compared with that of 
the polymer of the present invention due to the poor solubility. Further, 
repeatability of doping and dedoping was not good in this polymer. 
The novel alkyl group-substituted poly(quinone) according to the present 
invention is soluble in many organic solvents because the alkyl 
substitution group has been introduced thereinto, and thus, their 
application has been significantly broadened. For example, the polymer can 
be easily formed into fibers and films by dry molding with use of an 
appropriate solvent. In addition, since the polymer undergoes two-stepped 
electrochemical reduction by the application of rather small voltage while 
being accompanied by color changes, it can be suitably used as materials 
for electrochromic devices, n-type conductor photoluminescence devices and 
electroluminescence devices. 
Furthermore, according to the method of the present invention, wherein 
dehalogenation polycondensation of dihalogenated aromatic compounds of 
alkyl group-substituted quinone is conducted by making use of the reactive 
function of a nickel compound, an alkyl group-substituted poly(quinone) 
can be easily obtained while controlling the positions at which quinone 
units are combined together.