JP2670621B2 - Novel dithiotropolonate-based asymmetric metal complex and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel dithiotropolonate asymmetric metal complex having absorption in the near infrared region, which is useful for optical recording media and the like, and a method for producing the same.

[Conventional technology]

In recent years, as a recording layer of an optical recording medium, an organic dye thin film is used in place of a metal thin film, thermal deformation is generated by laser beam irradiation light, and recording is performed, and reproduction is performed by using a difference between reflected light and an undeformed portion. Reading has been put to practical use.
This organic dye thin film can control the melting point and decomposition point, has low thermal conductivity, and can form a recording thin film layer by a coating method.
This is a method that can be expected to improve productivity and reduce costs.

[Problems to be solved by the invention]

However, the organic dye thin film has a disadvantage that the organic dye is discolored by natural light or a reproduction light laser beam, and the long-term stability is not sufficient.In addition, the solvent used when forming the thin film by the coating method is limited to halogenated hydrocarbons. There are various practical problems in relation to the resin material used as the substrate. Therefore, at present, researches on dyes or high-performance light stabilizers with improved storage stability against red to near-infrared light and resistance to reproduction degradation are being actively conducted.

An object of the present invention is to provide a novel dithiotropolonate asymmetric metal complex having absorption in the near infrared region, which is useful for optical recording media and the like, and a method for producing the same.

[Means for solving the problem]

According to the present invention, general formula [I] (Wherein R represents a hydrogen atom or an alkyl group, M represents a nickel metal, and A represents a counter cation, etc.), and a novel dithiotropolonate asymmetric metal complex represented by The following general formula [II] (In the formula, R represents a hydrogen atom or an alkyl group, and M represents a nickel metal.) And a dithiotropolonate-based metal complex represented by the following general formula [III]: Where M is nickel metal, and A is a counter cation,
Represent each. ) A bis (cis-1,2-dicyano-1,2-ethylenedithiolate) metal complex represented by the formula: (Wherein R represents a hydrogen atom or an alkyl group, M represents a nickel metal, and A represents a counter cation, respectively) and a method for producing a novel dithiotropolonate asymmetric metal complex is provided. To be done.

The novel dithiotroporoneo-based asymmetric metal complex represented by the above general formula [I] of the present invention has absorption ability in the near-infrared region, and thus is particularly suitable for optical recording media, particularly singlet oxygen quenching. It is useful as a char. In addition to the optical recording medium, the metal complex can also be used as a filter for infrared light-sensitive materials, a heat ray blocking material, a stabilizer for various organic chemicals, plastics, agricultural chemicals, rubber, etc., an antioxidant, a bactericide, etc. Compound.

Specific examples of the metal complex represented by the general formula [I] according to the present invention include, but are not limited to, those in which the following complex anions and complex cations are combined.

(I) Specific examples of complex anions: (Dithiotropolonate) (1,2-dicyanoethylene
Thiolate) nickel anion: (4-isoproldithiotropolonate) (1,2-di
(Cyanoethylene thiolate) nickel anion (ii) Specific examples of complex cation (counter cation A) N (C_TwoH_Five)_Four: Tetraethylammonium cation, N (N-C_FourH₉)_Four: Tetra-n-butylammonium oxide
Thion,: Benzyltri-n-butylammonium cation,: N-laurylpyridinium cation,: N-benzylpicolinium cation, N (CH_Three)₃(C₁₆H₃₃): Trimethyl-n-hexade
Canmonium cation, P (N-C_FourH_Three)_Four: Tetra-n-butylphosphonium dioxide
Thion, P (C_TwoH_Five) (C₆H₁₂)_Three: Ethyltri-n-hexylpho
Sphonium cation, P (C₈H₁₇)_Four: Tetra-n-octylphosphonium carbonate
Thion.

The metal complex of the general formula [I] provided by the present invention is, for example, the compound of the general formula [II] (In the formula, R represents a hydrogen atom or an alkyl group, and M represents a nickel metal.) And a dithiotropolonate-based metal complex represented by the following general formula [III]: Where M is nickel metal, and A is a counter cation,
Represent each. ) Can be easily obtained by reacting with a bis (cis-1,2-dicyano-1,2-ethylenedithiolate) metal complex onium salt represented by

That is, in order to easily and conveniently obtain the metal complex represented by the general formula [I] of the present invention, the dithiotropolonate-based metal complex represented by the general formula [II] and the bis (represented by the general formula [III] ( (cis-1,2-dicyano-1,2-ethylenedithiolate) metal complex It is preferable to utilize a ligand exchange reaction with an onium salt.

This production method of the present invention is usually carried out in an organic solvent, preferably under reflux conditions. As the organic solvent in this case, acetone, acetonitrile, 1,2-dichloroethane, dimethylsulfoxide and the like which dissolve the metal complex represented by the general formulas [II] and [III] are preferably used.

In carrying out the present invention, the molar ratio of the metal complex of the general formula [II] to the metal complex of the general formula [III] is preferably 1: 1 to 1: 0.8. The two kinds of metal complexes are dissolved in the organic solvent,
The reaction proceeds by heating the system to the reflux temperature of the solvent or 80 to 90 ° C. The reaction time is 0.5 to 6 hours, preferably 1 to 2 hours. The reaction is terminated by maintaining the reaction system for the above-mentioned time.

The dithiotropolonate-based metal complex represented by the general formula [II], which is one of the raw materials in the production method of the present invention, can be easily obtained by the following method. That is, first, a tropolone-based compound such as tropolone and 4-alkyltropolone is heated and reacted with phosphorus pentasulfide in an organic solvent, optionally in a nitrogen gas atmosphere, to obtain a dithioltropolone-phosphorus sulfide complex, and then, A nickel metal ion compound or an aqueous solution thereof is added to the reaction system, and the produced complex and the metal ion are heated and reacted to obtain a dithiotropolonate metal complex. In this case, the dithioltropolones / phosphorus sulfide complex as an intermediate can be subjected to the second stage metal complex formation reaction as it is without separating the organic solvent. It is also possible to take it out from the organic solvent and again heat-react it with the nickel metal ion in the organic solvent.

As the organic solvent in this case, any of polar and nonpolar solvents can be used, but polar solvents are preferable from the viewpoint of dissolution of the reaction system and solubility of the reaction product, and alcohols, ketones, ethers, esters And amides are preferred. These solvents have an advantage that the formed metal complex precipitates as crystals in the solvent at the same time as the reaction. When a non-polar hydrocarbon or halogenated hydrocarbon solvent is used, the formed metal complex often dissolves in the solvent, and the number of processing steps after the reaction is increased. There is no. Particularly suitable solvents include dioxane.

In carrying out this method, the molar ratio of tropolones to phosphorus pentasulfide is preferably in the range of 1: 1.0 to 1: 2.0, particularly 1: 1.
The range of 1 to 1: 1.25 is preferable. Although the amount of the solvent used is not particularly limited, in the case of dioxane, it is usually preferably in the range of 2 to 20 times by weight, more preferably about 8 to 10 times by weight of the tropolone. The first-stage reaction is preferably carried out under heating and under reflux, and the reaction time is 0.5 to 8.0 hours, preferably 2.0 to 4.0 hours. By maintaining in dioxane for the above-mentioned time, the reaction system changes from pale yellow to dark reddish brown, and a reddish brown precipitate comes out.

Then, in the case of subjecting it to the second stage reaction, in the above state, the nickel metal ion compound is dissolved in the same or a small amount of water and added. In this case, the addition amount of the nickel metal ion compound is 0.5 to 1.0 mol, preferably 0.5 to 0.7 mol, relative to 1 mol of the raw material tropolones. When the nickel metal ion compound is added, the reaction system generally turns black, but the reaction is carried out at that temperature, preferably under reflux (in a hot water bath). The reaction is 0.5
By maintaining ~ 4.0 hours, preferably 1-2.5 hours,
Almost finished.

After the completion of the reaction, by cooling, in the case of many polyvalent metals, black crystals precipitate. The crystals are separated by filtration to obtain the desired dithiotropolonate-based metal complex. The obtained metal complex is, if necessary, acetone /
It can be recrystallized from a mixed solvent such as ethanol.

In addition, bis (cis-1,2-dicyano-1,2 represented by the general formula [III], which is one of the raw materials in the production method of the present invention,
The (ethylenedithiolate) metal complex onium salt can be obtained, for example, by the following method. That is, first In
According to the method described in organic Synthesis 10 , 8 (1967), sodium-cis-1,2-dicyano-1,2-
By synthesizing ethylene dithiolate, then reacting the compound with a nickel metal compound such as nickel chloride, and further adding, for example, a quaternary ammonium or phosphonium to the reaction solution, bis (cis-1,2- Dicyano
An onium salt is obtained from a 1,2-ethylenedithiolate) metal complex.

〔The invention's effect〕

The novel metal complex represented by the above general formula [I] of the present invention has an absorption ability in the near-infrared region by itself, so that it is used as an optical recording medium, particularly as a singlet oxygen quencher.
Useful. In addition to the optical recording medium, the metal complex can also be used as a filter of an infrared sensitive material, a heat ray blocking material, a stabilizer for various organic chemicals, plastics, agricultural chemicals, rubber, etc., an antioxidant and a bactericide.

Furthermore, since the production method of the present invention may utilize a ligand exchange reaction between the metal complex represented by the general formula [II] and the metal complex onium salt represented by the general formula [III],
It can be said that the manufacturing method is extremely advantageous industrially.

〔Example〕

Next, the present invention will be described in more detail with reference to examples. All percentages and parts shown below are based on weight.

Reference Example 1 Synthesis of bis (dithiotropolonate) nickel complex Tropolone 5.00 parts (0.0409 mol) and phosphorus pentasulfide 10.91
Parts (0.0491 mol) were suspended in 50 parts of dioxane, heated under reflux and stirred for 3 hours. After the reaction, the mixture was allowed to cool, and the precipitate was separated by filtration to obtain 10.06 parts of a reddish brown substance. This product was hardly dissolved in acetone, 1,1-dichloroethane, or the like, and did not melt or decompose even when heated to 300 ° C. The product is considered to be a complex or ester of dithioltropolone and phosphorus sulfide, but its structure was not elucidated. But, The following reactions were performed assuming the structure.

4.99 parts of the above composite was suspended in 50 parts of dioxane, and 3.57 parts (0.015 mol) of nickel chloride hexahydrate was dissolved in 15 parts of water and added. In a hot water bath, the color of the solution turned purple-black at about 50 ° C. after heating was started, and the mixture was stirred for 2 hours under reflux. After the reaction, the reaction system was cooled and the precipitate was filtered off to give a black crystal.
I got 1.18 copies. When this crystal was recrystallized from pyridine, the melting point of the obtained purified crystal was 328 ° C. (decomposition). (It agrees with the literature value.) The elemental analysis values of the obtained purified nickel complex were as follows.

Reference Example 2 Synthesis of bis (4-isopropyldithiotropolonate) nickel complex 4-Isopropyltropolone (hinokitiol) 2.46
Part (0.015 mol) and 3.99 parts (0.018 mol) of phosphorus pentasulfide were suspended in 50 parts of dioxane, heated under reflux and stirred for 3.5 hours. Initially, the red color changed to dark reddish brown, and a dark reddish brown precipitate was observed. After the completion of the reaction, the reaction system is cooled once, and 1.83 parts (0.0075 mol) of nickel chloride hexahydrate
Was dissolved in 10 parts of water, added to the reaction system, and stirred in a hot water bath at reflux for 2 hours. After the reaction, the reaction system was left to cool, and the precipitate was separated by filtration to obtain 2.52 parts of green-black crystals. The obtained crystals had a melting point of 205 to 207 ° C., and the yield was 74.4% based on hinokitiol. When the crystals were recrystallized from acetone, green-black crystals having a melting point of 206 to 207 ° C. were obtained.

The elemental analysis values of the obtained purified nickel complex were as follows.

Reference Example 3 Synthesis of bis (1,2-dicyano-1,2-ethylenedithiolate) nickel tetra-n-butylammonium salt 5.6 parts of sodium-cis-1,2-dicyano-1,2-ethylenedithiolate synthesized as described in Inorganic Synthesis 10 , 8 (1967) was added to water / methanol (1: 1 V / V).
Dissolve in 60 parts, and add 3.6 parts of nickel chloride hexahydrate to 20 parts of water.
When added to a solution dissolved in a part, it became dark reddish brown. Then, a solution prepared by dissolving 10.3 parts of tetra-n-butylammonium bromide in 20 parts of water / methanol (1: 1 V / V) was added to the above product, and the mixture was stirred at room temperature for 1 hour.

The precipitated orange-red crystals were filtered and recrystallized from a mixed solvent of acetone / butanol to obtain 11.2 parts of purified crystals. The melting point of the obtained purified crystals was 141 to 142 ° C (the literature value is 143 to 144 ° C).

Reference Example 4 Synthesis of bis (1,2-dicyano-1,2-ethylenedithiolate) nickel tetra-n-butylphosphonium salt Purified crystals having a melting point of 168 to 169 ° C were obtained in the same manner as in Reference Example 3 except that tetra-n-butylphosphonium bromide was used instead of tetra-n-butylammonium bromide.

Example 1 Synthesis of (dithiotropolonate) (1,2-dicyanoethylenethiolate) nickel tetra-n-butylammonium salt metal complex 0.55 parts of the bis (dithiotropolonate) nickel complex obtained in Reference Example 1 and the bis (1,2-
0.99 parts of dicyano-1,2-ethylenedithiolate) nickel tetra-n-butylammonium salt was heated to 40 parts of 1,2-dichloroethane under reflux for stirring for 2 hours. After completion of the reaction, the crude product obtained by distilling off the solvent was recrystallized from a mixed solvent of 1,2-dichloroethane / acetic acid ethyl ester (1: 1 V / V) to give bright black crystals 0.6
I got one copy. Mp 161-162 ° C.

The elemental analysis values and the near infrared absorption spectrum of the obtained metal complex are as follows, and the infrared absorption spectrum (KBr tablet method) is shown in FIG.

Near infrared absorption spectrum: λmax (1,2-dichloroethane) 810 nm, ε: 0.40 × 10 ⁴ Example 2 (4-isopropyldithiotropolonate) (1,2-dicyanoethylenethiolate) nickel tetra-n- Synthesis of butylammonium salt metal complex 0.45 parts of the bis (4-isopropyldithiotropolonate) nickel complex obtained in Reference Example 2 and the bis (1,2-dicyano-1,2-ethylenedithiolate) nickel tetra-n obtained in Reference Example 3 -Butyl ammonium salt 0.83
Part of the mixture was stirred at reflux with acetonitrile for 2.5 hours. After completion of the reaction, the crude product obtained by distilling off the solvent was extracted with methanol to obtain crystals, and ethyl acetate / chloroform (1: 1 V / V) was used using silica gel (trade name; Wakogel C-300). V) Separation and purification by column chromatography using a mixed solvent as a developing solvent gave 0.48 part of bright black crystals. Melting point 105-106 ° C.

The elemental analysis value and the near infrared absorption spectrum of the obtained metal complex are as follows, and the infrared absorption spectrum (KBr tablet method) is shown in FIG.

Near infrared absorption spectrum: λmax (1,2-dichloroethane) 800 nm, ε: 0.41 × 10 ⁴ Example 3 (4-isopropyldithiotropolonate) (1,2-dicyanoethylenethiolate) nickel tetra-n- Synthesis of metal complexes of butylphosphonium salts 0.90 parts of the bis (4-isopropyldithiotropolonate) nickel complex obtained in Reference Example 2 and bis (1,2-dicyano-1,2-ethylenedithiolate) nickel tetra-n obtained in Reference Example 4 -Butylphosphonium salt 1.74
Parts were used together with 50 parts of 1,2-dichloroethane to obtain 0.98 parts of black crystals by the same operation as in Example 2. Melting point 99
~ 102 ° C.

The elemental analysis value and near infrared absorption spectrum of the obtained metal complex are as follows, and the infrared absorption spectrum (KBr tablet method) is shown in FIG.

Near infrared absorption spectrum: λmax (1,2-dichloroethane) 800nm, ε: 0.46 × 10 ⁴

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 show infrared absorption spectra of the metal complexes obtained in Examples 1 to 3 of the present invention.

Claims (2)

(57) [Claims] 1. A compound of the formula [I] (In the formula, R represents a hydrogen atom or an alkyl group, M represents a nickel metal, and A represents a counter cation.) A new dithiotropolonate asymmetric metal complex represented by the formula: 2. The general formula [II] (In the formula, R represents a hydrogen atom or an alkyl group, and M represents a nickel metal.) And a dithiotropolonate-based metal complex represented by the following general formula [III]: Where M is nickel metal, and A is a counter cation,
Represent each. ) A bis (cis-1,2-dicyano-1,2-ethylenedithiolate) metal complex represented by the formula: (In the formula, R represents a hydrogen atom or an alkyl group, M represents a nickel metal, and A represents a counter cation.) A method of producing a novel dithiotropolonate asymmetric metal complex.