JPH11201964A - Method for evaluation of electron transfer speed by using methine dye oxidant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method in which a reducing power and a hole capturing power of a chemical substance re evaluated and in which, e.g. a hole capturing-type color sensitizer of a photographic photosensitive material can be evalauted simply, by a method wherein the one-electron oxidant of a methine dye expressed by a specific formula is mixed with the chemical substance and a change in the absorption of light is measured. SOLUTION: For example, an electron transfer capability of a chemical substance as a color sensitizer used for a silver halide emulsion to which a sensitizing dye is added is evaluated by using a methine dye, preferably by using a cyanine dye which is expressed by Formula I, Formula II or Formula III (in the formulae, Z1 to Z6 represent S, O, N, Se and C, L1 to L5 represent a methine group, La to Lh represent a methylene group, n1 to n8 represent an integer of 2 to 4, I1 to I6 represent an integer of 0 to 4, V1 to V5 represent a monovalent substituent, M1 to M3 represent electric charge equilibrium pair ions, and m1 to m3 represent a number required to neutralize the electric charge of a molecule). A prescribed oxidizing agent is added to the solution of the methine dye or the cyanine dye which is selected among from them, a one-electron oxidant is obtained, the chemical substance to be tested is added, a change in the absorption of light is measured, and a reaction speed is found, e.g. as a pseudo first-order reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for using a one-electron oxidized methine dye to evaluate the reducing power of organic and inorganic chemical substances.

[0002]

2. Description of the Related Art If a spectral sensitizer is added to a silver halide emulsion in an amount exceeding an optimum amount, a large desensitization is brought about. This is commonly referred to as dye desensitization,
This is a phenomenon in which desensitization occurs in a photosensitive region peculiar to silver halide which has substantially no light absorption by a sensitizing dye. If the dye desensitization is large, the overall sensitivity will be low although there is a spectral sensitizing effect. In other words, as the dye desensitization decreases, the spectral sensitivity increases accordingly. Therefore, in spectral sensitization technology, improvement of dye desensitization is a major problem.

[0003] In addition, T. Tani et al.
Journal of Physica
As described in Chemistry, Vol. 94, p. 1298 (1990), it is known that a sensitizing dye having a reduction potential nobler than -1.25 v has a low relative quantum yield of spectral sensitization. I have. In order to increase the relative quantum yield of the spectral sensitization of such dyes, the “Theory of the Photogragh process”
Phonic Process) pp. 259-265 (1966), super sensitization by hole capture has been proposed.

As a supersensitizer for eliminating the above-mentioned desensitization, a compound having an oxidation potential lower than that of the sensitizing dye is used in combination with a one-electron oxidized form of the sensitizing dye (that is, a dye positive dye). (Holes) may be reduced (electron transfer from the supersensitizer, ie, hole capture). For example, U.S. Pat. Nos. 2,313,922, 2,075,046, 2,448,858, 2,680,686, British Patent 1,230,449
And Belgian Patent Nos. 771 and 168 are known. Therefore, those conventionally useful as supersensitizers have the ability to transfer electrons to the one-electron oxidized form of the dye.
Conventionally, methods for evaluating this electron transfer in a photosensitive material include:
The ESR method and the double flash Denver method have been known. However, these methods require time and effort to prepare a light-sensitive material and use an expensive measuring device, and a simpler evaluation method has been required.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple method for evaluating a hole-capturing supersensitizer in a silver halide photographic light-sensitive material.

[0006]

The object of the present invention has been achieved by the following means as a result of intensive studies. That is, (1) mixing a one-electron oxidized methine dye with a chemical substance,
A method for evaluating the rate of electron transfer from a chemical substance to an oxidized methine dye from a change in absorption of the methine dye. (2) As the methine dye of (1), the following general formula (I),
The evaluation method according to (1), wherein the dye represented by (II) or (III) is used. General formula (I)

[0007]

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Wherein Z ₁ and Z ₂ are a sulfur atom, an oxygen atom,
These are nitrogen, selenium, and carbon. L ₁ represents a methine group. La and Lb represent a methylene group. n ₁ and n ₂ represent ₂ , 3, and 4, respectively. V ₁ and V ₂ represent a monovalent substituent. l ₁ and l ₂ represent 0, 1, ₂ , 3, and 4.
M ₁ represents a charge balancing counter ion, and m ₁ represents a number required to neutralize the charge of the molecule. General formula (II)

[0009]

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Where Z_ThreeAnd Z_FourIs a sulfur atom, an oxygen atom,
These are nitrogen, selenium, and carbon. L_TwoIs methine
Represents a group. Lc, Ld and Le represent a methylene group.
You. n_Three, N_Four, And n_FiveRepresents 2, 3, and 4. V_Threeas well as
V_FourRepresents a monovalent substituent. l _ThreeAnd l_FourIs 0,1,
Represents 2, 3, and 4. M_TwoRepresents a charge-balancing counter ion, m_Two
Represents the number required to neutralize the molecular charge. General formula (III)

[0011]

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Wherein Z ₅ and Z ₆ are a sulfur atom, an oxygen atom,
These are nitrogen, selenium, and carbon. L ₃ , L ₄ and L ₅ represent a methine group. Lf, Lg, and Lh represent a methylene group. n ₆ , n ₇ and n ₈ represent 2, 3, and 4, respectively. V ₅ and V ₆ represent a monovalent substituent. l ₅ and l ₆
Represents 0, 1, 2, 3, and 4. M ₃ represents a charge balancing counter ion, and m ₃ represents a number required to neutralize the charge of the molecule.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The compounds used in the present invention and the measuring method are described in detail below. As the methine dye used in the present invention, any methine dye can be used, and preferred examples include a cyanine dye, a merocyanine dye, a rhodocyanine dye, a trinuclear merocyanine dye, an allopolar dye, a hemicyanine dye, and a styryl dye. For more information on these dyes, see FM Harmer, Heterocyclic Compounds-Cyanine Dyes and Relatized Compounds.
ed Compounds) ", John Willie and Sons
(John Wiley & Sons)-New York, London, 1
964, DMSturmer, Heterocyclic Compound Special Topics in Heterocyclic Chemistry (H
eterocyclic Compounds-Special topics in heterocycl
ic chemistry) ", Chapter 18, Section 14, pages 482 to 515, and the like. The general formulas of cyanine dyes, merocyanine dyes and rhodacyanine dyes are described in U.S. Pat. No. 5,340,694, Nos. 21 and 22 (XI), (X
Those shown in II) and (XIII) are preferred.
More preferred are cyanine dyes.

The dye used in the present invention must have a stable one-electron oxidant. If it is unstable,
It is decomposed before mixing with a chemical substance, and it is difficult to measure the electron transfer from the chemical substance to the one-electron oxidant of the dye from the change in absorption of the one-electron oxidant of the dye.

[0015] Examples of methine dyes in which the one-electron oxidant is stable are described by JR L. Leonard and R. L. Parton (JR Lenhard, RL Parto).
n), Journal of American Chemical Society (J. Am. Chem. Soc.), No. 10
9, 5803, (1987), J. R. Leonard, A.A. Mentor (JR Lenh)
ard, A .; A. Muenter, Proceeding Electrochemical Society (Proc. E)
electrochem. Soc. ), Vol. 88, No. 97
P., (1988), J. R. Leonard, R. L. Parton, R.E.
L. Parton), Journal of Organic Chemistry (J. Org. Chem.), No. 55
Vol. 49, (1990), J. R. Leonard, A. D. Cameron (JR Lenhar)
d. D. Cameron), Journal of Physical Chemistry (J. Phys. Che)
m. ), Vol. 97, p. 4916, (1993), and a methine chain-crosslinked cyanine dye.

Particularly preferably, the compounds represented by the general formulas (I) and (I)
The cyanine dyes represented by I) and (III). Hereinafter, the general formulas (I), (II) and (III) will be described in detail. In Z ₁ , Z ₂ , Z ₃ , Z ₄ , Z ₅ , and Z ₆ , a sulfur atom, an oxygen atom, a nitrogen atom (NR represents an alkyl group, an aryl group, a heterocyclic group), a selenium atom, And carbon atoms (C-R'R ", R 'and R" represent a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group). R, R '
And the alkyl group represented by R ″ has 1 carbon atom
To 18, preferably an unsubstituted alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methyl, ethyl, butyl, pentyl);
Preferably, it is a substituted alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, methoxyethyl,
Hydroxyethyl). Further, an unsubstituted aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms (eg, phenyl group, 1-naphthyl group), and 6 to 20 carbon atoms, preferably Number 6 to 10, more preferably 6 to 8 carbon atoms
A substituted aryl group (e.g., a p-methoxyphenyl group,
p-methylphenyl group, p-chlorophenyl group and the like. ), Having 1 to 20 carbon atoms, preferably 3 carbon atoms
To 10, more preferably an unsubstituted heterocyclic group having 4 to 8 carbon atoms (e.g., 2-furyl, 2-thienyl, 2-
Pyridyl group, 3-pyrazolyl, 3-isoxazolyl,
3-isothiazolyl, 2-imidazolyl, 2-oxazolyl, 2-thiazolyl, 2-pyridazyl, 2-pyrimidyl, 3-pyrazyl, 2- (1,3,5-triazolyl), 3-
(1,2,4-triazolyl), 5-tetrazolyl), a substituted heterocyclic group having 1 to 20, preferably 3 to 10, more preferably 4 to 8 carbon atoms (for example, 5-methyl-2 -Thienyl group, 4-methoxy-2-pyridyl group, etc.). Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, a phosphorus atom and the like. R, R 'and R "are preferably methyl, ethyl, phenyl and 2-pyridyl, more preferably methyl and ethyl.

Z ₁ , Z ₂ , Z ₃ , Z ₄ , Z ₅ and Z ₆ are preferably a sulfur atom and an oxygen atom, and more preferably a sulfur atom.

V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , and V ₆ may be any monovalent substituents. For example, halogen atoms (eg, chlorine, bromine, iodine, fluorine), Mercapto group, cyano group, carboxyl group, phosphate group, sulfo group,
Hydroxy group, having 1 to 10 carbon atoms, preferably 2 carbon atoms
To 8, more preferably a carbamoyl group having 2 to 5 carbon atoms (eg, methylcarbamoyl, ethylcarbamoyl, morpholinocarbonyl), 0 to 10, preferably 2 to 8 carbon atoms, more preferably 2 to 5 carbon atoms. Sulfamoyl groups (eg, methylsulfamoyl, ethylsulfamoyl, piperidinosulfonyl),
A nitro group, an alkoxy group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms (eg, methoxy, ethoxy, 2-methoxyethoxy, 2-phenylethoxy); An aryloxy group having 20, preferably 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms (for example, phenoxy, p-
Methylphenoxy, p-chlorophenoxy, naphthoxy),

An acyl group having 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms (eg, acetyl, benzoyl, trichloroacetyl), 1 to 20 carbon atoms, preferably 2 carbon atoms From 1
2, more preferably an acyloxy group having 2 to 8 carbon atoms (eg, acetyloxy, benzoyloxy), an acylamino group having 1 to 20, preferably 2 to 12, more preferably 2 to 8 carbon atoms (eg, Acetylamino), having 1 to 20 carbon atoms, preferably 1 carbon atom
To 10, more preferably a sulfonyl group having 1 to 8 carbon atoms (for example, methanesulfonyl, ethanesulfonyl,
Benzenesulfonyl, etc.), 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms.
(E.g., methanesulfinyl, benzenesulfinyl), a sulfonylamino group having 1 to 20, preferably 1 to 10, and more preferably 1 to 8 carbon atoms (e.g., methanesulfonylamino, ethanesulfonylamino, benzene) Such as sulfonylamino),

An amino group, a substituted amino group having 1 to 20, preferably 1 to 12, more preferably 1 to 8 carbon atoms (eg, methylamino, dimethylamino, benzylamino, anilino, diphenylamino);
An ammonium group having 0 to 15 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms (for example, trimethylammonium group, triethylammonium group), 0 to 15 carbon atoms, preferably 1 to 1 carbon atoms
0, more preferably a hydrazino group having 1 to 6 carbon atoms (for example, a trimethylhydrazino group);
5, preferably a ureido group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms (for example, ureido group, N,
An N-dimethylureido group), an imide group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms (for example, a succinimide group);
To 20, preferably 1 to 12, more preferably 1 to 8 alkyl or arylthio groups (eg, methylthio, ethylthio, carboxyethylthio, sulfobutylthio, phenylthio, etc.), carbon 2
To 20, preferably 2 to 12 carbon atoms, more preferably 2 to 8 alkoxycarbonyl groups (eg methoxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl), 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms. More preferably, an aryloxycarbonyl group having 6 to 8 carbon atoms (eg, phenoxycarbonyl),

An unsubstituted alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methyl, ethyl, propyl, butyl), and 1 to 18 carbon atoms, preferably 1 to 1 carbon atoms
0, more preferably a substituted alkyl group having 1 to 5 carbon atoms (for example, hydroxymethyl, trifluoromethyl, benzyl, carboxyethyl, ethoxycarbonylmethyl, acetylaminomethyl, and here preferably also having 2 to 18 carbon atoms, Preferably 3 to 1 carbon atoms
0, particularly preferably an unsaturated hydrocarbon group having 3 to 5 carbon atoms (for example, vinyl group, ethynyl group, 1-cyclohexenyl group, benzylidene group, benzylidene group) is also included in the substituted alkyl group. ), Having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, and more preferably 6 carbon atoms.
To 10 substituted or unsubstituted aryl groups (eg, phenyl, naphthyl, p-carboxyphenyl, p-nitrophenyl, 3,5 dichlorophenyl, p-cyanophenyl, m-fluorophenyl, p-tolyl),

A substituted carbon atom having 1 to 20, preferably 2 to 10, more preferably 4 to 6 carbon atoms, wherein the heteroatom is selected from oxygen, nitrogen, sulfur, selenium, phosphorus and the like; And heterocyclic groups (eg, pyridyl, 5-methylpyridyl, thienyl, furyl, morpholino, tetrahydrofurfuryl) which may be used. Further, a structure in which a benzene ring, a naphthalene ring, or an anthracene ring is condensed can be employed. Further, these substituents may be further substituted with a monovalent substituent represented by V ₁ or the like.

Preferred as V _{1 to} V ₆ are the above-mentioned alkyl groups, aryl groups, alkoxy groups, halogen atoms, acyl groups, cyano groups, sulfonyl groups and benzene ring condensates, more preferably alkyl groups, aryl groups. , A halogen atom, an acyl group, a sulfonyl group, and a benzene ring condensation, and particularly preferably a methyl group, a phenyl group, a methoxy group, a chlorine atom, a bromine atom, an iodine atom, and a benzene ring condensation. Most preferred are a phenyl group, a chlorine atom, a bromine atom and an iodine atom.

As l ₁ , l ₂ , l ₃ , l ₄ , l ₅ , l ₆ , it is preferably 0, 1, 2, more preferably 0, 1, and particularly preferably 0. When l _{1 to} l ₆ are 2 or more, V _{1 to} V ₆ are repeated, but need not be the same.

La, Lb, Lc, Ld, Le, Lf, L
g and Lh represent an unsubstituted methylene group or a substituted methylene group (for example, a methylene group substituted with the aforementioned V. Specifically, a methyl-substituted methylene group, an ethyl-substituted methylene group, a phenyl-substituted methylene group, Group-substituted methylene group, halogen atom (for example, chlorine atom, bromine atom)
And a substituted methylene group. ) La, Lb, L
Preferably, c, Le, Lf, and Lh are unsubstituted methylene groups. Ld and Lg are preferably an unsubstituted methylene group or a methyl-substituted methylene group.

N ₁ , n ₂ , n ₃ , n ₄ , n ₅ , n ₆ , n ₇ , n ₈
Is 2,3,4, preferably 2,3, and more preferably 3. When n _{1 to} n ₈ are 2 or more, L
a to Lh are repeated, but need not be the same.

L ₁ , L ₂ , L ₃ , L ₄ and L ₅ each independently represent a methine group. The methine group represented by L _{1 to} L ₅ may have a substituent. Examples of the substituent include a substituted or unsubstituted C ₁ to C 15, preferably C ₁ to C 10, more preferably C ₁ to C ₅ carbon atom. An alkyl group of the formulas 1 to 5 (for example, methyl, ethyl, 2-carboxyethyl),
A substituted or unsubstituted aryl group having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms (eg, phenyl, o-carboxyphenyl); 20, preferably 4 to 15 carbon atoms, more preferably 6 to 10 carbon atoms, and oxygen atoms, nitrogen atoms, sulfur atoms as complex atoms,
Heterocyclic groups such as selenium atom and phosphorus atom (for example, N, N
-, A diethyl barbituric acid group), a halogen atom (for example, chlorine, bromine, fluorine, iodine), a carbon number of 1 to 15,
Preferably, it is an alkoxy group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methoxy, ethoxy), 1 to 15 carbon atoms, preferably 1 to 1 carbon atoms.
0, more preferably an alkylthio group having 1 to 5 carbon atoms (eg, methylthio, ethylthio);
0, preferably an arylthio group having 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms (eg, phenylthio), 0 to 15 carbon atoms, preferably 2 to 1 carbon atoms
0, more preferably an amino group having 4 to 10 carbon atoms (eg, N, N-diphenylamino, N-methyl-N-phenylamino, N-methylpiperazino) and the like. L ₁ , L ₂ , L ₃ , L ₄ and L ₅ are preferably unsubstituted methine groups.

M ₁ , M ₂ , and M ₃ are included in the formula to indicate the presence of a cation or an anion when necessary to neutralize the ionic charge of the dye. Typical cations include hydrogen ions (H ⁺ ), inorganic cations such as alkali metal ions (eg, sodium ion, potassium ion, lithium ion), alkaline earth metal ions (eg, calcium ion), and ammonium ions ( For example, organic ions such as ammonium ion, tetraalkylammonium ion, pyridinium ion and ethylpyridinium ion) can be mentioned. The anion may be either an inorganic anion or an organic anion, such as a halogen anion (for example, a fluorine ion, a chloride ion, an iodine ion), a substituted arylsulfonate ion (for example, p-toluenesulfonate ion, p-chlorobenzenesulfonic acid ion, aryldisulfonic acid ion (for example, 1,3-benzenesulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-
Naphthalenedisulfonic acid ion), alkyl sulfate ion (for example, methyl sulfate ion), sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, and trifluoromethanesulfonic acid ion. . Further, another dye having a charge opposite to that of the ionic polymer or the dye may be used. In the present invention, for example, a sulfo group SO ₃ ^- but is indicated as, when having a proton as a counter ion SO ₃
It is also possible to write H. m ₁ , m ₂ , and m ₃ represent the numbers required to balance the charges, and are 0 when a salt is formed in the molecule. Preferably, 0, 1, 2, 3, 4
And more preferably 1.

The general formulas (I) and (II) of the present invention are described below.
Specific examples of the compound represented by (III) are shown below, but the invention is not limited thereto. Specific examples of general formula (I)

[0030]

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Specific examples of the general formula (II)

[0032]

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Specific examples of the general formula (III)

[0034]

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The methine dye of the present invention can be obtained by a method described in FM Harmer, "Heterocyclic Compounds-Cyanine Dyes and Relat Compounds".
ed Compounds) ", John Willie and Sons
(John Wiley & Sons)-New York, London, 1
964, DMSturmer, Heterocyclic Compound Special Topics in Heterocyclic Chemistry (H
eterocyclic Compounds-Special topics in heterocycl
ic chemistry), Chapter 18, Section 14, pp. 482-515, John Wiley and Sons.
ley & Sons), New York, London, 1977, "Rodd's Chemistry of Carbon Compounds" 2nd.
Ed.vol.IV, partB, 1977, Chapter 15, Chapters 369-422, ElsevierScience Publishing Company, Inc.
Inc.), New York, and the like.

The method of one-electron oxidation of the methine dye of the present invention will be described. As the oxidation method, electrochemical oxidation on the electrode and chemical oxidation using an oxidizing agent are possible, and either may be used. The oxidizing agent in the chemical oxidation may be any one, and examples thereof include the following. These oxidizing agents are used in an amount of from 1 equivalent of methine dye to 0.1 equivalent.
It is preferable to use about 5 equivalents.

[0037]

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The preferred oxidizing agent is (1).

After the one-electron oxidized form of the methine dye is generated by the above method, a chemical substance having a reducing power (either an inorganic or organic compound, but preferably an organic compound) is mixed, and the mixture is chemically treated. Electron transfer from a substance to a one-electron oxidized form of methine dye can be evaluated by decreasing absorption of one-electron oxidized form of methine dye or increasing absorption of methine dye. The amount of the chemical substance is preferably in excess of the one-electron oxidized form of the methine dye, more preferably 10 to 100 equivalents, in order to handle the reaction in a pseudo-first order.
Particularly preferred is 15 to 40 equivalents.

The measurement temperature can be selected from the range of -800 ° C to 270 ° C. The range is preferably from 0 ° C to 80 ° C, more preferably from 20 ° C to 50 ° C. Most preferably, it is 25 ° C. Water, N,
It can be selected from any range from polar solvents such as N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO) to non-polar solvents such as benzene and hexane. For example, polar solvents such as DMF and DMSO, alcohols such as methanol and ethanol, nitriles such as acetonitrile and benzonitrile, esters such as ethyl acetate, tetrahydrofuran, 1,2
Ethers such as dimethoxyethane; Preferred are nitriles and water, and more preferred is acetonitrile. In the case of an aqueous solvent, Briton-
Use a buffer such as Robinson Buffer
H can be adjusted. Further, a mixed solvent thereof can be used. Particularly preferably, acetonitrile /
It is a mixed solvent of water buffer. As the measurement solvent, a solvent that does not react with or reduce the one-electron oxidized form of the methine dye and does not react with a chemical substance is preferable.

The absorption of the one-electron oxidized form of the methine dye and the absorption of the methine dye may be measured by a usual spectrophotometer, or a stopped-flow meter is useful for tracking a high-speed electron transfer reaction.

[0042]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Measurement Using Hydroquinone as Chemical Substance a) Three-liquid-mixed stopped-flow measuring device (manufactured by Otsuka Electronics Co., Ltd.)
Was used. As the solution A, 4.76 m of the dye (III-1) was used.
g of acetonitrile in 200 ml (0.00004M
/ L), a solution of 8.22 mg of oxidizing agent (1) in 250 ml of acetonitrile (0.000036 M / l) was used immediately. BRBuffer (pH = 5) /
A mixed solvent of acetonitrile / water = 1/1/1 was used. As the liquid C, a solution of 7.92 mg of hydroquinone in acetonitrile / water = 2/1 (0.00036 M / l) was used.
It was used. The three liquids A, B and C are mixed, and the dye (III)
-1) From the attenuation of the absorption at 555 nm of the one-electron oxidant,
The electron transfer rate from the hydroquinone to the one-electron oxidized product of the dye (III-1) was evaluated. In addition, pH after mixing 3 liquids
Was 6.54. The reaction was determined as a pseudo-first-order reaction, and the rate was determined. As a result, the reaction rate (logk) = 3.6 (M
^-1 S ^-1 ). b) 3 liquid mixed stopped flow measuring device (Otsuka Electronics)
Was used. 4.67 mg of dye (II-1) as solution A
Of acetonitrile in 200 ml (0.00004M /
1) To 8.22 mg of acetonitrile 2
A 50 ml solution (0.000036 M / l) was added and used immediately. As the solution B, a mixed solvent of BRBuffer (pH = 5) / acetonitrile / water = 1/1/1 was used.
As the liquid C, a solution of 7.92 mg of hydroquinone in aceF nitrile / water = 2/1 (0.00036 M / l) was used. A, B, and C are mixed, and the dye (II-1) is mixed.
From the increase in absorption at 680 nm, the electron transfer rate from hydroquinone to the one-electron oxidized form of dye (II-1) was evaluated. The pH after mixing the three liquids was 6.54. The reaction was determined as a pseudo-first-order reaction, and the rate was determined. As a result, a reaction rate (logk) = 4.8 (M ⁻¹ S ⁻¹ ) was obtained. c) 3 liquid mixing stopped flow measuring device (Otsuka Electronics)
Was used. Solution A includes a solution of 3.91 mg of dye (I-1) in 200 ml of acetonitrile (0.00004 M /
1) To 8.22 mg of acetonitrile 2
A 50 ml solution (0.000036 M / l) was added and used immediately. As the solution B, a mixed solvent of BRBuffer (pH = 5) / acetonitrile / water = 1/1/1 was used.
As the solution C, a solution of 7.92 mg of hydroquinone in acetonitrile / water = 2/1 (0.00036 M / l) was used. The three solutions A, B, and C were mixed, and the rate of electron transfer from hydroquinone to the one-electron oxidized form of the dye (I-1) was evaluated from the increase in the absorption of the dye (I-1) at 585 nm. The pH after mixing the three liquids was 6.54. The reaction was determined as a pseudo-first-order reaction, and the rate was determined. As a result, a reaction rate (logk) = 6.9 (M ⁻¹ S ⁻¹ ) was obtained. In the above measurements a, b, and c), the same measurement can be performed using other chemical substances instead of hydroquinone. Also, the pH of BRBuffer can be changed as appropriate.

[0044]

The present invention provides a method of mixing a one-electron oxidized form of methine dye with a chemical substance and evaluating the rate of electron transfer from the chemical substance to the oxidized form of methine dye from a change in absorption of the methine dye, It is useful for evaluating the reducing power and hole capturing power of chemical substances.

Claims (2)

[Claims] 1. A method of mixing a one-electron oxidized form of methine dye with a chemical substance and evaluating the rate of electron transfer from the chemical substance to the oxidized methine dye form based on a change in absorption of the methine dye. 2. The methine dye of claim 1, which has the following general formula:
Dye represented by (I), (II) or (III)
The evaluation method according to claim 1, wherein the evaluation method is used. General formula (I)Where Z₁And Z_TwoAre sulfur, oxygen, nitrogen,
A ren atom and a carbon atom. L₁Represents a methine group. L
a and Lb represent a methylene group. n₁And n_TwoIs 2,
Represents 3 and 4. V₁And V_TwoRepresents a monovalent substituent.
l₁And l_TwoRepresents 0, 1, 2, 3, and 4. M₁Is the charge uniformity
Represents a counter ion, m₁Is necessary to neutralize the molecular charge.
Indicates the required number. Formula (II)Where Z_ThreeAnd Z_FourAre sulfur, oxygen, nitrogen,
A ren atom and a carbon atom. L_TwoRepresents a methine group. L
c, Ld, and Le represent a methylene group. n_Three, N_Four,
And n_FiveRepresents 2, 3, and 4. V_ThreeAnd V_FourIs a monovalent
Represents a substituent. l _ThreeAnd l_FourRepresents 0, 1, 2, 3, 4
You. M_TwoRepresents a charge-balancing counter ion, m_TwoIs the charge of the molecule
Indicates the number required for neutralization. General formula (III)Where Z_FiveAnd Z₆Are sulfur, oxygen, nitrogen,
A ren atom and a carbon atom. L_Three, L_Four, And L_FiveIs meth
Represents a group. Lf, Lg and Lh each represent a methylene group.
You. n₆, N₇, And n₈Represents 2, 3, and 4. V_Fiveas well as
V₆Represents a monovalent substituent. l_Five, And l₆Is 0,1,
Represents 2, 3, and 4. M_ThreeRepresents a charge-balancing counter ion, m_Three
Represents the number required to neutralize the molecular charge.