JP5852323B2 - Method for producing disulfide polymer - Google Patents

Description

The present invention relates to a manufacturing method of the available disulfide polymers as cathode material for a secondary battery.

  In recent years, development of new energy materials is expected due to environmental problems and energy problems. In particular, the development of next-generation secondary batteries that serve as the foundation for electric vehicles is an urgent research topic. Currently, the most widely used positive electrode materials for secondary batteries are inorganic oxides such as lithium cobalt acid, but their rare metal resources are problematic. Therefore, development of a new organic positive electrode material in consideration of the abundance of resources and environmental aspects is required.

  A material having a disulfide bond (—S—S—) (disulfide-based material) is used in various applications, but in recent years, the possibility of use as an anode active material of a secondary battery has been attracting attention. When an oxidation-reduction cycle is electrochemically generated on a disulfide bond, a charge / discharge phenomenon occurs. A secondary battery using a polymer mainly composed of this bond as an anode active material is the performance of a conventional lithium ion secondary battery. (See Non-Patent Document 1, Patent Documents 1 and 2).

JP 9-82329 A JP 2007-234338 A

M. Liu, S. J. Visco, L. C. De Jonghe, J. Electrochem. Soc., 138, 1896-1901 (1991)

  However, although disulfide-based materials have been expected so far, no remarkable progress has been made toward practical use due to problems in synthesis and the like.

  For example, as an example of synthesizing a polymer mainly composed of disulfide, oxidation of thiol is known, but a side reaction often proceeds, and a copolymer for the purpose of changing the electronic environment on the disulfide bond, In order to introduce a plurality of organic groups, other synthesis methods are currently required.

This invention is made | formed in view of said situation, and it aims at providing the manufacturing method of the novel disulfide polymer which can be utilized as a positive electrode substance.

  The method for producing a disulfide polymer according to the present invention has the following characteristics.

A thiosulfonate ester monomer having two or more thiosulfonate ester bonds (—S—SO ₂ —) represented by the following formula (1), and two or more thiol groups (—SH) represented by the following formula (2) A disulfide polymer having a structure represented by the following formula (3) is synthesized by mixing with a thiol monomer having an amine.

^{_{A (-S-SO 2 -R 1}} ) a (1)
In the formula (1), A represents an organic group. R ¹ independently represents an organic group in each substituent, and may be the same or different. a represents an integer of 2 or more.

B (-SH) _b (2)
In the formula (2), B represents an organic group. b represents an integer of 2 or more.

(-S-A-SS-B-S-) _n (3)
In Formula (3), A is the same as A in Formula (1), B is the same as B in Formula (2), and n is an integer of 1 or more. A and B may be the same or different.

  A further invention is characterized in that the synthesis of the disulfide polymer is carried out under solvent-free conditions.

  In a further invention, the amine is an aniline.

  In a further invention, the thiosulfonic acid ester monomer comprises a cyclic disulfide compound having a disulfide bond in the ring or a disulfide compound having two or more disulfide bonds and a sulfinate in the presence of iodine in a solvent-free condition. It was obtained by mixing in 1.

  A further invention is that the disulfide compound having two or more disulfide bonds is obtained by mixing a thiol compound having two or more thiol groups and a thiosulfonic acid ester in the presence of amines under solvent-free conditions. It is characterized by that.

  Further, the invention is characterized in that the thiosulfonic acid ester bond is a benzenethiosulfonic acid ester bond.

  Further invention is characterized in that A in the formula (1) is an alkylene group or an aryl group, and B in the formula (2) is an alkylene group or an aryl group.

  In a further invention, the thiosulfonic acid ester monomer is one of the compounds having the structures shown below,

  The thiol monomer is any one of the compounds having the structures shown below.

ADVANTAGE OF THE INVENTION According to this invention, the disulfide polymer which can be utilized as a positive electrode substance can be manufactured easily .

It is the schematic which shows the principle of the battery using a disulfide polymer. It is explanatory drawing which shows an example of a solvent-free reaction. An example of a solventless reaction is shown, (a) is a photograph before the reaction, and (b) is a photograph after the reaction. 2 is a graph showing the charge / discharge behavior of a battery using the disulfide polymer of Example 1. FIG.

In the method for producing a disulfide polymer according to the present invention, a thiosulfonic acid ester monomer having two or more thiosulfonic acid ester bonds (—S—SO ₂ —) represented by the following formula (1) is used as the first monomer.

^{_{A (-S-SO 2 -R 1}} ) a (1)
In the formula (1), A represents an organic group. R ¹ independently represents an organic group in each substituent, and may be the same or different. a represents an integer of 2 or more.

  A in Formula (1) is not particularly limited as long as it is an organic group bonded to the S atom in the thiosulfonate bond at at least two positions, but is preferably an alkylene group or an aryl group. a is an integer of 2 or more, preferably 6 or less, and more preferably 2 or 3.

Examples of the organic group A include an ethylene group (CH ₂ CH ₂ ), a 1,3-propylene group (CH ₂ CH ₂ CH ₂ ), and a 1,4-butylene group (CH ₂ CH ₂ ) when a = _2. CH ₂ CH ₂ ), 1,4-phenylene group (p-C ₆ H ₄ ), 1,3-phenylene group (m-C ₆ H ₄ ), 1,2-phenylene group (o-C ₆ H ₄ ) , Etc. The organic group A when a = 2 is a pyridinylene group in which two hydrogen atoms of the pyridine ring are substituted, for example, a 2,3-pyridinylene group (C ₅ H ₃ N), a 2,4-pyridinylene group. (C ₅ H ₃ N), 2,5-pyridinylene group (C ₅ H ₃ N), 3,5-pyridinylene group (C ₅ H ₃ N), or two hydrogen atoms of the naphthalene ring were substituted naphthylene group, for example, 1,5-naphthylene _{(C 10} H 6), 1,8- naphthylene group _(C 10 _{H 6)} can also be mentioned. The organic group A in the case of a = 3 includes 1,3,5-trisubstituted benzene group (C ₆ H ₃ ), trisubstituted-triphenylene group, trisubstituted-1,3,5-triazine group and the like. Can be mentioned. Tri-substitution means a structure in which three hydrogen atoms are substituted. For example, a 1,3,5-tri-substituted benzene group is a structure in which hydrogens at the 1,3,5-positions of the benzene ring are substituted. It is.

As the organic group ^{R 1,} for example, an alkyl group, an aryl group, and particularly, for example, a methyl group _(CH 3), ethyl group _{(C 2 H} 5), phenyl group _{(C 6 H} 5) , Etc. In particular, from the viewpoint of synthesis, the thiosulfonic acid ester bond in Formula (1) is preferably a benzenethiosulfonic acid ester bond, and in this case, R ¹ is a phenyl group (C ₆ H ₅ ).

  Specific examples of the thiosulfonic acid ester monomer are given below.

  A preferred example of the thiosulfonic acid ester monomer is obtained by mixing a cyclic disulfide compound having a disulfide bond (-SS-) in the ring and a sulfinate in the presence of iodine in the absence of solvent. is there. The reaction formula of an example in which the cyclic disulfide compound is 1,2-dithiane and the sulfinate is sodium benzenesulfinate is shown below.

Another preferred example of the thiosulfonic acid ester monomer was obtained by mixing a disulfide compound having two or more disulfide bonds (-SS-) with a sulfinate in the presence of iodine in the absence of solvent. Is. The disulfide compound may have an alkyl disulfide group, for example, may have a methyl disulfide group. A disulfide compound having two or more disulfide bonds is obtained by mixing a thiol compound having two or more thiol groups and a thiosulfonic acid ester in the presence of amines under solvent-free conditions. Can be used. As the amines, any one or more of primary amines (R—NH ₂ ), secondary amines, and tertiary amines can be used. For example, anilns, triethylamine, pyridine and the like can be used. Of these, anilines can be preferably used. Specifically, for example, aniline, toluidine, chloroaniline and the like can be used. The thiol compound having two or more thiol groups is 1,2-benzenedithiol, 1,4-benzenedithiol, or 1,3,5-benzenetrithiol, and the thiosulfonic acid ester is methyl benzenethiosulfonate A series of reaction formulas of an example in which the ester is an ester and the sulfinate is sodium benzenesulfinate is shown below.

  In the synthesis of the thiosulfonic acid ester monomer, as shown in the above reaction formula, the thiosulfonic acid ester used as a raw material (benzenethiosulfonic acid methyl ester in the above reaction formula) is obtained together with the main product. This thiosulfonic acid ester can be reused as a raw material, and it is possible to efficiently synthesize a thiosulfonic acid ester monomer.

  When a thiosulfonate ester monomer is synthesized by thiosulfonate esterifying a disulfide compound with a sulfinate, the amount of the sulfinate is within a range of 0.9 to 1.1 times the molar equivalent of the disulfide compound. Can be set to The equivalent is an amount corresponding to the number of functional groups. The amount of iodine can be 0.5 to 1 times the molar ratio of the sulfinate. As reaction conditions for dithiosulfonic acid esterification, the reaction temperature can be set, for example, within a range of 40 ° C. to 80 ° C. and the reaction time within a range of 12 to 96 hours. As the sulfinate, an alkali metal salt of arylsulfinate such as sodium benzenesulfinate shown in the above reaction formula can be used.

  Moreover, when a disulfide compound is synthesized from a thiol compound and a thiosulfonic acid ester, the amount of the thiosulfonic acid ester can be set within a range of 0.9 to 2.0 times the equivalent in terms of molar ratio. Moreover, the quantity of amines can use the quantity 1-2 times by molar ratio with respect to thiosulfonic acid ester. As reaction conditions for disulfide synthesis, for example, the reaction temperature can be set within a range of 10 ° C. to 40 ° C. and the reaction time within a range of 1 to 120 minutes.

  In the method for producing a disulfide polymer according to the present invention, a thiol monomer having two or more thiol groups (—SH) represented by the following formula (2) is used as the second monomer.

B (-SH) _b (2)
In the formula (2), B represents an organic group. b represents an integer of 2 or more.

  Although B in Formula (2) will not be specifically limited if it is an organic group couple | bonded with S atom in a thiol group at at least two places, It is preferable that it is an alkylene group or an aryl group. b is an integer of 2 or more, preferably 6 or less, and more preferably 2 or 3.

As the organic group B, for example, when b = 2, an ethylene group (CH ₂ CH ₂ ), a 1,3-propylene group (CH ₂ CH ₂ CH ₂ ), a 1,4-butylene group (CH ₂ CH _2). CH ₂ CH ₂ ), 1,4-phenylene group (p-C ₆ H ₄ ), 1,3-phenylene group (m-C ₆ H ₄ ), 1,2-phenylene group (o-C ₆ H ₄ ) , Etc. The organic group A when a = 2 is a pyridinylene group in which two hydrogen atoms of the pyridine ring are substituted, for example, a 2,3-pyridinylene group (C ₅ H ₃ N), a 2,4-pyridinylene group. (C ₅ H ₃ N), 2,5-pyridinylene group (C ₅ H ₃ N), 3,5-pyridinylene group (C ₅ H ₃ N), or two hydrogen atoms of the naphthalene ring were substituted naphthylene group, for example, 1,5-naphthylene _{(C 10} H 6), 1,8- naphthylene group _(C 10 _{H 6)} can also be mentioned. The organic group A in the case of a = 3 includes 1,3,5-trisubstituted benzene group (C ₆ H ₃ ), trisubstituted-triphenylene group, trisubstituted-1,3,5-triazine group and the like. Can be mentioned. Tri-substitution means a structure in which three hydrogen atoms are substituted. For example, a 1,3,5-tri-substituted benzene group is a structure in which hydrogens at the 1,3,5-positions of the benzene ring are substituted. It is.

  Specific examples of the thiol monomer are given below. These names are 1,2-ethanedithiol, 1,4-butanedithiol, 1,4-benzenedithiol, 1,2-benzenedithiol, 1,3,5-benzenetrithiol.

  The disulfide polymer having the structure represented by the following formula (3) is synthesized by mixing the monomer of the formula (1) and the monomer of the formula (2) in the presence of amines.

(-S-A-SS-B-S-) _n (3)
In Formula (3), A is the same as A in Formula (1), B is the same as B in Formula (2), and n is an integer of 1 or more. However, A and B may be the same or different.

  This synthesis is preferably performed under solvent-free conditions. Side reactions can be suppressed under solvent-free conditions. However, a solvent may be used as long as no by-product is generated. The solventless reaction can usually be a solid reaction (solid phase reaction).

As the amines, any one or more of primary amine (R—NH ₂ ), secondary amine, and tertiary amine can be used, and examples thereof include anilnes, triethylamine, and pyridine. Of these, anilines are preferred. As anilines, for example, aniline, toluidine, chloroaniline and the like can be used. Toluidine and chloroaniline may be o (ortho), m (meta), or p (para).

  At the laboratory level, the synthesis reaction can be performed by adding each component to a mortar and mixing with a pestle. After uniformly mixing, the mixture may be left in a test tube or stirring may be continued. The reaction temperature can be in the range of 0 to 50 ° C. or in the range of 10 to 40 ° C., for example, room temperature (around 25 ° C.). The reaction time can be 1 minute or longer, preferably 3 minutes or longer, more preferably 5 minutes or longer. The reaction time may be 1 hour or more or 3 hours or more. The reaction time may be 12 hours or less, 6 hours or less, 3 hours or less, or 1 hour or less. The synthesis reaction (disulfide bond formation) proceeds rapidly. In addition, synthesis using a mortar is a laboratory level synthesis, and a reactor with a stirring function can be used at an industrial level (mass synthesis). After the reaction, the polymer can be purified by an appropriate method such as solvent extraction, column separation, or crystallization.

  The mixing ratio of the thiosulfonate ester monomer having two or more thiosulfonate ester bonds represented by the formula (1) and the thiol monomer having two or more thiol groups represented by the formula (2) is a molar ratio, It can be 2: 1 to 1: 2 or 3: 2 to 2: 3. In addition, the amine can be used in an amount of 1 to 2 times in molar ratio to the thiosulfonic acid ester monomer.

  In the disulfide polymer, n in the formula (3) is an integer of 1 or more, but may be 2 or more, 3 or more, or 10 or more. As n, for example, n is 20 or more and 800 or less. Good. Further, the molecular weight of the disulfide polymer may be, for example, 5000 or more and 100,000 or less in terms of weight average molecular weight.

  An example of the reaction formula for the synthesis of the disulfide polymer is given below. In these reactions, it has been confirmed that the yield in terms of mole is 70% or more. First, an example of a homopolymer is shown.

  Next, an example of a copolymer (alternate copolymer) is shown.

  Hereinafter, the mechanism of the synthesis reaction will be described in detail. The present invention is not limited to the following mechanism.

  The organic disulfide is synthesized by a nucleophilic reaction (cross-coupling reaction) for the S atom of thiol. At this time, in the conventional synthesis method, as in reaction mechanism 1 below, the thiol also attacks the product to cause cleavage-recombination of disulfide bonds, resulting in disproportionation separately from the target product. The product obtained is obtained. This is a phenomenon observed in a reaction in a solvent. The product obtained is usually difficult to separate.

    [Reaction mechanism 1]

  However, in the present invention, a reaction is used in which an organic disulfide is synthesized using a thiosulfonic acid ester and a thiol, preferably in the presence of an amine, preferably under solvent-free conditions. The mechanism of this reaction is shown in Reaction Mechanism 2 below.

    [Reaction mechanism 2]

In this reaction, particularly under solvent-free conditions, the thiol is controlled in nucleophilicity by the interaction between —SH—H... H ₂ N— that occurs when amines and thiol crystals are mixed. Disproportionation is suppressed because only the divalent sulfur is selectively attacked. By utilizing this reaction for the polymerization of the monomer of formula (1) and the monomer of formula (2), a disulfide polymer in which organic groups A and organic groups B are alternately arranged can be obtained. At this time, if different organic groups are used as the organic group A and the organic group B, the synthesis proceeds with a structure in which the organic group A and the organic group B are alternately arranged, and an alternating copolymer is obtained. Is.

  By the way, the thiosulfonic acid ester bond in the thiosulfonic acid ester monomer can utilize a cross-coupling reaction using iodine. The general reaction formula of this coupling reaction and the reaction mechanism (reaction mechanism 3) are shown below. This reaction itself proceeds with or without a solvent.

    [Reaction formula of cross-coupling using iodine]

    [Reaction mechanism 3]

  When two or more thiosulfonic acid ester bonds are present, the product is further oxidized by iodine and decomposes in the presence of a solvent. The reaction mechanism when the reaction is carried out in a solvent using 1,2-dithiane is shown in the following reaction mechanism 4.

    [Reaction mechanism 4]

  However, under the solvent-free conditions, the further oxidation as described above does not proceed, and a compound having two or more target thiosulfonic acid ester bonds can be obtained as shown in Reaction Mechanism 5 below.

    [Reaction mechanism 5]

  As described above, the above compounds and polymers can be synthesized under solvent-free conditions. Therefore, the synthesis efficiency can be increased. In addition, the solventless synthesis can be carried out without using an organic solvent or reducing the amount of the organic solvent used, thereby reducing the burden on the environment.

  The disulfide polymer obtained by the present invention has a structure represented by the above formula (3), and in particular, the following disulfide copolymer which is an alternating copolymer can be preferably obtained.

(-S-A-SS-B-S-) _n (3)
In this formula (3), A and B are organic groups having different structures, and n represents an integer of 1 or more.

  When A and B are different organic groups, the electronic environment of disulfide bonds can be controlled.

  When A and B are the same, the disulfide polymer can be represented by the following formula (4). Note that n in the equation (4) may be considered to be twice the n in the equation (3).

(-S-A-S-) _n (4)
In Formula (4), A is an organic group, and n represents an integer of 1 or more.

  In the disulfide polymer represented by the formulas (3) and (4), A may be an alkylene group or an aryl group, and B may be an alkylene group or an aryl group. These substituents can have the same structure as already described. Specifically, A and B may be any of the structures in parentheses shown below.

  Specific examples of the disulfide polymer are shown below. First, an example of a homopolymer is shown.

  Next, an example of a copolymer (alternate copolymer) is shown.

  The disulfide polymer exhibits charge / discharge characteristics and can be used as a positive electrode material for a secondary battery. The positive electrode can be configured to include, for example, a disulfide polymer, PVDF (polyvinylidene fluoride), and carbon black. The content of the disulfide polymer in the positive electrode can be, for example, about 1 to 50% by mass.

FIG. 1 is a schematic diagram showing the principle of a battery using a disulfide polymer. This battery is applied to a lithium ion battery, using lithium (Li) as a negative electrode and an organic disulfide polymer as a positive electrode material. In the positive electrode, at the time of discharge, the S—S bond is cleaved to generate electric power. On the other hand, during charging, the cleaved S and S are recombined by the action of Li ⁺ and the S—S bond is regenerated. Thus, the battery can be used by the charge / discharge characteristics by the cleavage-recombination of disulfide bonds. And the radius of sulfur atom (88 pm) is much smaller than the radius of cobalt atom (152 pm), which is a conventional positive electrode material. If one atom receives one electron, theoretically, Therefore, it is possible to form a cathode material having a much higher capacity.

[Used equipment]
For 1H and 13C NMR, JEOL JNM-MY60FT and JEOL JNM-GSX 500N NMR spectrometer were used. As the infrared spectrophotometer, FT-IR 5020 manufactured by Hitachi-Nicolet and FT / IR-4100ST manufactured by JASCO Corporation were used. As a mass spectrometer, JMS SX-102 (EI, FAB) manufactured by JEOL and GC-MS QP5050A manufactured by Shimadzu Corporation were used. As the melting point measuring device, a trace melting point measuring device MP-S3 manufactured by Yanagimoto Seisakusho was used. The synthesis experiment in the absence of a solvent was carried out by controlling a reaction rate using a dry thermo unit DTU-1C manufactured by TAITEC, a reagent tube packed in a test tube with a stopper. The reaction was confirmed by thin layer chromatography using a Merck aluminum sheet Silicagel 60 F254. In the solventless reaction, each sample was mixed using an agate mortar 1 and a pestle 2 as shown in FIG. Yield (%) was converted to mol (mol%). Using these experimental facilities, synthesis and analysis of products in a solvent-free environment were performed.

[Synthesis of Methylbenzenethiosulfonate (Compound 1)]
After adding dimethyl disulfide (188 mg, 2.0 mmol), sodium benzenesulfinate (984 mg, 6.0 mmol) and iodine (1.01 g, 4.0 mmol) to a 5 mL stoppered test tube, stir with a test tube mixer. A dry thermo unit was kept at 50 ° C. for 1 day. The reaction product solidified in the lower layer was sufficiently crushed with a spatula, extracted with 50 mL of dichloromethane, and the organic layer washed once with an aqueous sodium thiosulfate solution and twice with brine was dried over anhydrous magnesium sulfate. The desiccant was filtered off, and the solvent was distilled off under reduced pressure with an evaporator to obtain “Compound 1” as a colorless transparent oil represented by the following reaction formula (652 mg, yield 87%).

¹ H NMR (CDCl ₃ , 60 MHz): δ 7.6-7.9 (d, 5H), 2.5 (s, 3H).
MS (EI): m / z [M] ⁺ = 188 (65), 141 (100), 125 (13).
The reaction formula of the synthesis | combination of the compound 1 is shown.

[Synthesis of Alkyl Disulfide (Compound 2)]
After putting “Compound 1” (1.88 g, 10 mmol) and 1,2-ethanedithiol (471 mg, 5.0 mmol) on an agate mortar and stirring, add p-toluidine (803 mg, 7.5 mmol) for 5 minutes. Rubbed well. The obtained reaction product was extracted with n-hexane: dichloromethane = 1: 3, and the extract was directly purified by silica gel column chromatography (developing solvent: n-hexane: dichloromethane = 1: 3). The solvent was distilled off under reduced pressure to obtain “Compound 2” as a colorless and transparent oil represented by the following reaction formula (763 mg, yield 82%).

¹ H NMR (CDCl ₃ , 60 MHz): δ 3.01 (s, 4H), 2.44 (s, 6H).
MS (EI): m / z [M] ⁺ = 139 (94), 124 (22), 107 (100).
The reaction formula of the synthesis | combination of the compound 2 is shown.

[Synthesis of Aryl Disulfide (Compound 3) (1,4-phenylene)]
After putting “Compound 1” (903 mg, 4.8 mmol) and 1,4-benzenedithiol (284 mg, 2.0 mmol) into an Erlenmeyer flask with a 50 mL stopper, p-toluidine (514 mg, 4.8 mmol) and n -Hexane 5mL was added and it was made to fully stir for 10 minutes. The obtained reaction product was extracted with 20 mL of n-hexane, and the extract was directly purified by silica gel column chromatography (developing solvent: n-hexane). The solvent was distilled off under reduced pressure to obtain “Compound 3” shown in the following reaction formula as a yellow oil (389 mg, 83% yield).

IRγmax (KBr): 484 cm ^-1 (SS).
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.4-8.1 (m, 4H), 2.4 (s, 6H).
MS (EI): m / z [M] ⁺ = 234 (100), 187 (77), 140 (32).
The reaction formula for the synthesis of Compound 3 is shown.

[Synthesis of Aryl Disulfide (Compound 4) (1,2-phenylene)]
After putting “Compound 1” (451 mg, 2.4 mmol) and 1,2-benzenedithiol (142 mg, 1.0 mmol) on an agate mortar and stirring, add p-toluidine (257 mg, 2.4 mmol) and add 5 Rinse well for a minute. The reaction product was transferred to a test tube, and 20 mL of n-hexane was added in several portions and extracted while grinding. This extract was directly purified by column chromatography (developing solvent: n-hexane), and the solvent was distilled off under reduced pressure to obtain “compound 4” shown in the following reaction formula as a yellow oil (150 mg, yield). (Rate 64%).

IRγmax (KBr): 475, 438 cm ^-1 (SS).
¹ H NMR (CDCl ₃ , 60 MHz): δ 6.1-6.5 (d, 4H), 1.3 (s, 6H).
The reaction formula for the synthesis of Compound 4 is shown.

[Synthesis of dithiosulfonic acid ester having ethylene unit (compound 5)]
Add "Compound 2" (745 mg, 4.0 mmol), sodium benzenesulfinate (1.96 g, 12 mmol), and iodine (2.03 g, 8.0 mmol) to a 5 mL stoppered test tube, then stir with a test tube mixer Then, it was kept at 50 ° C. with a dry thermo unit for 2 days. The reaction product was sufficiently crushed and then extracted with 50 mL of dichloromethane. The organic layer washed once with an aqueous sodium thiosulfate solution and twice with brine was dried over anhydrous magnesium sulfate. The desiccant was filtered off and the solvent was distilled off under reduced pressure to produce the target compound “Compound 5” and the by-product “Compound 1”. This was separated by column chromatography (developing solvent: n-hexane: dichloromethane = 2: 3) to obtain a colorless solid “compound 5” represented by the following reaction formula (1.07 g, yield 71%).

mp: 79-80 ℃
IRγmax (KBr): 1326, 1142, 1075 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.7-7.9 (d, 10H), 3.3 (s, 4H).
The reaction formula for the synthesis of Compound 5 is shown.

[Synthesis of dithiosulfonic acid ester having 1,4-butylene unit (compound 6)]
Add 1,2-dithiane (120 mg, 1.0 mmol), sodium benzenesulfinate (820 mg, 5.0 mmol), and iodine (1.01 g, 4.0 mmol) to a 5 mL stoppered test tube, and use a test tube mixer. The mixture was stirred and kept at 50 ° C. with a dry thermo unit for 1 day. The reaction product was extracted with 50 ml of dichloromethane while being sufficiently crushed, and the organic layer washed once with aqueous sodium thiosulfate solution and twice with brine was dried over anhydrous magnesium sulfate. The desiccant was filtered off, and the solvent was distilled off under reduced pressure to obtain “Compound 6” shown in the following reaction formula as colorless crystals (362 mg, yield 90%).

mp: 92-93 ℃ (Reference value: 93-94 ℃)
IRγmax (KBr): 1329, 1143, 1078 cm ^-1 .
¹ H NMR (CDCl ₃ , 500 MHz): δ 7.91 (d, 4H, J = 7.5 Hz), 7.65 (dd, 4H, J = 7.5, 7.5 Hz), 7.57 (dd, 4H, J = 7.5, 7.5 Hz) ), 2.93 (t, 4H, J = 7.0 Hz), 1.65 (quintet, 4 H, J = 3.5 Hz).
¹³ C NMR (126 MHz): δ 142.65, 133.82, 129.39, 126.92, 35.15, 27.48.
MS (FAB): m / z [M + H] ⁺ = 403.
HRMS (EI): m / z [M] = 403.0177.
References in mp are Hayashi, S., Ueki, H., Harano, S., Komiya, J., Iyama, S., Harano, K. and Miyata, K., Chem. Pharm. Bull. 12 , 1271-1276 (1964).

  The reaction formula for the synthesis of Compound 6 is shown.

[Synthesis of dithiosulfonic acid ester having 1,4-phenylene unit (compound 7)]
Add "Compound 3" (468 mg, 2.0 mmol), sodium benzenesulfinate (1.96 g, 12 mmol), and iodine (2.03 g, 8 mmol) to a 5 mL test tube with a stopper, then stir with a test tube mixer Then, it was kept at 50 ° C. with a dry thermo unit and placed for 3 days. The reaction product was extracted with 50 mL of dichloromethane while being sufficiently crushed, and the organic layer washed once with an aqueous sodium thiosulfate solution and twice with brine was dried over anhydrous magnesium sulfate. The desiccant was filtered off and the solvent was distilled off under reduced pressure to produce the target compound “Compound 7” and the by-product “Compound 1”. This was separated by column chromatography (developing solvent: n-hexane: dichloromethane = 1: 3) to obtain “compound 7” in the form of white powder shown in the following reaction formula (632 mg, yield 74%) .

mp: 165-167 ° C
IRγmax (KBr): 1326, 1144, 1074 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.2-8.5 (m, 14 H).
MS (EI): m / z [M] ⁺ = 422 (56), 297 (25), 281 (36), 141 (100), 125 (55).
HRMS (EI): m / z [M] = 421.9791.
The reaction formula for the synthesis of Compound 7 is shown.

[Synthesis of dithiosulfonic acid ester (compound 8) having 1,2-phenylene unit]
Put "Compound 4" (234 mg, 1 mmol), sodium benzenesulfinate (984 mg, 6 mmol) and iodine (1.01 g, 4 mmol) in a 5 mL stoppered test tube, and then stir with a test tube mixer. The dry thermo unit was kept at 50 ° C. and placed for 2 days. The reaction product was extracted with 50 mL of dichloromethane while being sufficiently crushed, and the organic layer washed once with an aqueous sodium thiosulfate solution and twice with brine was dried over anhydrous magnesium sulfate. The desiccant was filtered off and the solvent was distilled off under reduced pressure to produce the target compound “Compound 8” and the by-product “Compound 1”. This was separated by column chromatography (developing solvent: n-hexane: dichloromethane = 2: 3) to obtain “compound 8” in the form of white crystals shown in the following reaction formula (319 mg, yield 75%). .

mp: 152-154 ° C
IRγmax (KBr): 1326, 1141,1075 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.2-7.7 (m, 14 H).
The reaction formula for the synthesis of Compound 8 is shown.

[Example 1]
[Synthesis of disulfide polymer (polymer 9) (ethylene)]
After putting “Compound 5” (449 mg, 1.2 mmol) and 1,2-ethanedithiol (94 mg, 1.0 mmol) in an agate mortar and mixing, add p-toluidine (160 mg, 1.5 mmol) to add 5 Rinse well for a minute. The obtained reaction product was extracted with dichloromethane and purified by silica gel column chromatography (developing solvent: dichloromethane). The solvent was distilled off under reduced pressure to obtain “polymer 9” as a colorless crystalline solid represented by the following reaction formula (157 mg, yield 85%).

IRγmax (KBr): 2912, 481 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 3.0 (s, 4H).
MS (EI): m / z [M] ⁺ = 233 (19), 141 (26), 125 (27), 109 (9).
The reaction formula of the synthesis of the polymer 9 is shown.

[Example 2]
[Synthesis of Disulfide Polymer (Polymer 10) (1,4-butylene)]
After adding “Compound 6” (483 mg, 1.2 mmol) and 1,4-butanedithiol (122 mg, 1.0 mmol) on an agate mortar, add p-toluidine (160 mg, 1.5 mmol) and add 5 Rinse well for a minute. The obtained reaction product was extracted with dichloromethane and purified by silica gel column chromatography (developing solvent: dichloromethane). The solvent was distilled off under reduced pressure to obtain “polymer 10” as a white amorphous solid represented by the following reaction formula (211 mg, yield 86%).

IRγmax (KBr): 2925, 2852 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 2.7 (s, 4H), 1.8 (s, 4H).
MS (EI): m / z [M] ⁺ = 120 (100), 105 (2).
The reaction formula of the synthesis of the polymer 10 is shown.

[Example 3]
[Synthesis of Disulfide Polymer (Polymer 11) (1,4-butylene, 1,4-phenylene)]
After putting “Compound 6” (483 mg, 1.2 mmol) and 1,4-benzenedithiol (142 mg, 1.0 mmol) on an agate mortar and mixing, add p-toluidine (160 mg, 1.5 mmol) to add 5 Rinse well for a minute. The obtained reaction product was extracted with dichloromethane and purified by silica gel column chromatography (developing solvent: dichloromethane). The solvent was distilled off under reduced pressure to obtain “Polymer 11” represented by the following reaction formula (206 mg, yield 72%) as a yellow amorphous solid.

IRγmax (KBr): 2923, 485 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.4 (s, 4H), 2.6 (s, 4H), 1.7 (s, 4H).
MS (EI): m / z [M] ⁺ = 140 (6), 120 (100).
The reaction formula of the synthesis of the polymer 11 is shown.

[Example 4]
[Synthesis of Disulfide Polymer (Polymer 12) (1,4-butylene, 1,2-phenylene)]
After putting “Compound 6” (483 mg, 1.2 mmol) and 1,2-benzenedithiol (142 mg, 1.0 mmol) in an agate mortar and mixing, add p-toluidine (160 mg, 1.5 mmol) to add 5 Rinse well for a minute. The obtained reaction product was extracted with dichloromethane and purified by silica gel column chromatography (developing solvent: dichloromethane). The solvent was distilled off under reduced pressure to obtain “Polymer 12” as a colorless amorphous solid represented by the following reaction formula (241 mg, 85% yield).

IRγmax (KBr): 2924, 436 cm ^-1 .
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.3-7.6 (d, 4H), 2.7 (s, 4H), 1.7 (s, 4H).
MS (EI): m / z [M] ⁺ = 260 (11), 184 (14), 140 (38), 120 (100).
The reaction formula of the synthesis of the polymer 12 is shown.

[Example 5]
[Synthesis of Disulfide Polymer (Polymer 13) (1,2-phenylene, 1,4-phenylene)]
After putting “Compound 7” (270 mg, 0.64 mmol) and 1,2-benzenedithiol (75 mg, 0.53 mmol) on an agate mortar, add p-toluidine (128 mg, 0.80 mmol) for 5 minutes. Rubbed well. The obtained reaction product was extracted with dichloromethane and purified by silica gel column chromatography (developing solvent: dichloromethane). The solvent was distilled off under reduced pressure to obtain “Polymer 13” represented by the following reaction formula (241 mg, 85% yield) as a pale yellow amorphous solid.

IRγmax (KBr): 486 cm ^-1 (SS).
¹ H NMR (CDCl ₃ , 60 MHz): δ 7.3 (s, 8H).
MS (EI): m / z [M] ⁺ = 560 (1), 420 (1), 280 (17), 216 (16), 184 (9), 140 (100).
The reaction formula of the synthesis of the polymer 13 is shown.

[Example 6]
[Synthesis of Disulfide Polymer (Polymer 14)]
By the same method as described above, “Polymer 14” represented by the following reaction formula was obtained from “Compound 7” and 1,4-benzenedithiol.

  The reaction formula of the synthesis of the polymer 14 is shown.

[Solvent-free reaction]
FIG. 3 shows the progress of the solventless reaction (thiosulfonic acid esterification), (a) is a photograph of the test tube before the reaction, and (b) is a photograph of the test tube after the reaction. The white solid mixture has reacted and has turned brown (brown).

[Evaluation of charge / discharge performance of polymer]
In FIG. 4, the result of the charging / discharging evaluation of the lithium ion battery which used the disulfide polymer of Example 1 (polymer 9) as an anode active material is shown. In the test, charge (c) -discharge (d) was performed for 4 cycles under the following conditions (1c-1d-2c-2d-3c-3d-4c-4d).

Voltage: 1.5-4 V
Cathode: 10% active material (Disulfide polymer)
70% Carbon black
20% PVDF
Anode: Li metal
Electrolyte: LiPF6

When the polymer of Example 1 is used as the anode active material, the plateau potential range cannot be sufficiently confirmed, but the charge / discharge capacity is 280 to 240 AhKg ⁻¹ , which is a result exceeding the practical lithium transition metal active material. It was. Further, it was confirmed that the linear disulfide compound is a chemical species having good repeated durability.

  Similarly, in the lithium ion battery using Example 6 (polymer 14), charge / discharge properties were also confirmed. In this battery, a high battery capacity was confirmed, and a plateau potential range was also observed. The plateau potential range is a state in which the potential during discharge is kept constant.

Claims (8)

A thiosulfonate ester monomer having two or more thiosulfonate ester bonds (—S—SO ₂ —) represented by the following formula (1), and two or more thiol groups (—SH) represented by the following formula (2) A disulfide polymer production method comprising synthesizing a disulfide polymer having a structure represented by the following formula (3) by mixing a thiol monomer having an amine with an amine.
^{_{A (-S-SO 2 -R 1}} ) a (1)
In the formula (1), A represents an organic group. R ¹ independently represents an organic group in each substituent, and may be the same or different. a represents an integer of 2 or more.
B (-SH) _b (2)
In the formula (2), B represents an organic group. b represents an integer of 2 or more.
(-S-A-SS-B-S-) _n (3)
In Formula (3), A is the same as A in Formula (1), B is the same as B in Formula (2), and n is an integer of 1 or more. A and B may be the same or different.   The method for producing a disulfide polymer according to claim 1, wherein the synthesis of the disulfide polymer is performed under solvent-free conditions.   The method for producing a disulfide polymer according to claim 1, wherein the amine is an aniline.   The thiosulfonic acid ester monomer is prepared by mixing a cyclic disulfide compound having a disulfide bond in a ring, or a disulfide compound having two or more disulfide bonds and a sulfinate in the presence of iodine in a solvent-free condition. The method for producing a disulfide polymer according to any one of claims 1 to 3, wherein the disulfide polymer is obtained.   The disulfide compound having two or more disulfide bonds is obtained by mixing a thiol compound having two or more thiol groups and a thiosulfonic acid ester in the presence of amines without solvent. The method for producing a disulfide polymer according to claim 4, wherein:   The method for producing a disulfide polymer according to any one of claims 1 to 5, wherein the thiosulfonic acid ester bond is a benzenethiosulfonic acid ester bond.   A in formula (1) is an alkylene group or an aryl group, and B in formula (2) is an alkylene group or an aryl group, according to any one of claims 1 to 6, A process for producing the disulfide polymer described. The thiosulfonic acid ester monomer is one of the compounds having the structures shown below,
The method for producing a disulfide polymer according to any one of claims 1 to 7, wherein the thiol monomer is any one of compounds having the following structures.