JP2598963B2 - Process for producing dithiotropolonate-based metal complex and novel bis (4-alkyldithiotropolonate) metal complex - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improved method for producing a dithiotropolonate-based metal complex which is expected to be useful as an infrared absorber or a stabilizer for various organic materials, and a novel method for producing the same. Bis (4-alkyldithiotropolonate) metal complex.

(Prior art)

In recent years, with the development of recording media using semiconductor laser light, a near-infrared absorbing agent having specific absorption in the near-infrared region has been demanded. In addition to recording media, novel complexes that can be used as filters for infrared-sensitive materials, infrared selective absorption materials, heat-shielding materials, stabilizers for various organic chemicals and plastics, antioxidants or germicides, etc. It has been demanded.

The present inventors have found a dithiotropolonate-based metal complex as a complex having such near-infrared absorption characteristics or as a complex as a stabilizer for various organic materials. Conventionally, a method for producing a dithiotropolonate-based metal complex, particularly a bis (dithiotropolonate) metal complex, is described in J. Am. Chem. Soc. 92 , 229 by CEForbes & R. H. Holm.
7 (1970), which comprises chlorinating tropolone with thionyl chloride to form 2-chloro-tropolone, treating the resultant with triethyloxonium boron tetrafluoride, and treating with 1,2-diethoxy. Tropenylium boron tetrafluoride,
It is further reacted with sodium bisulfide in a nitrogen gas atmosphere to obtain dithiotropolone sodium salt, and further reacted with metal ions to obtain a bis (dithiotropolonate) metal complex. That is, since this metal complex is obtained through a complicated several-step synthesis reaction, it becomes expensive and its use is naturally limited.

As for the dithiotropolonate-based metal complex,
Only a bis (dithiotropolonate) metal complex is known, and a thiotropolone-based metal complex having a substituent is not known.

〔Purpose〕

An object of the present invention is to use a dithiotropolonate-based metal complex, which is expected to be useful as an infrared absorber or a stabilizer for various organic materials, at low cost using a drug as a raw material and in a two-step reaction, And a novel bis (4-alkyldithiotropolonate) metal complex.

〔Constitution〕

According to the present invention, there is provided a method for producing a dithiotropolonate-based metal complex, which comprises reacting a tropolone-based compound with phosphorus pentasulfide and then reacting the reaction product with a polyvalent metal ion. Also provided is a novel bis (4-alkyldithiotropolonate) metal complex represented by the following general formula.

(In the formula, R represents an alkyl group and M represents a polyvalent metal.) That is, in the production method of the present invention, first, a tropolone compound is reacted with phosphorus pentasulfide to form a dithioltropolone with phosphorus sulfide. A complex is produced, and the produced complex is further reacted with a polyvalent metal ion. According to the method, a dithiotropolonate-based metal complex can be easily and inexpensively obtained.

In the method of the present invention, a tropolone-based compound, that is, tropolone and a derivative thereof are used as a starting material,
Specific examples thereof include tropolone and 4-alkyltropolone represented by the following general formula (I).

(In the formula, R ′ represents a hydrogen atom or an alkyl group.) Further, among the compounds represented by the above general formula (I),
From the viewpoint of availability, tropolone [R ′ = H in the formula (I)] and hinokitiol [R ′ in the formula (I)
= CH (CH _{3) 2]} it is, is preferably used in particular.

In the method of the present invention, the first-stage reaction for forming a dithiol-tropolone-phosphorus sulfide complex and the second-stage reaction for forming a dithiotropolonate-based metal complex are usually carried out in an organic solvent. . That is, in the method of the present invention, first, a tropolone-based compound is heated and reacted with phosphorus pentasulfide in an organic solvent and optionally in a nitrogen gas atmosphere to obtain a dithiol-tropolone-phosphorus sulfide composite, and then the reaction is carried out. By adding a polyvalent metal ion compound or an aqueous solution thereof to the system, and reacting the produced complex with the metal ion by heating,
The desired dithiotropolonate-based metal complex is obtained. In this case, the dithiol tropolone / phosphorus sulfide complex as an intermediate can be subjected to the second-stage metal complex formation reaction without separating the organic solvent. It can also be removed from the organic solvent and reacted again with the polyvalent metal ion in the organic solvent by heating.

As the organic solvent used in the method of the present invention, any of a polar solvent and a non-polar solvent can be used, but a polar solvent is preferable from the viewpoint of dissolution of the reaction system and solubility of the reaction product, and alcohols, ketones, and 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 the method of the present invention, the molar ratio of tropolone to phosphorus pentasulfide is preferably in the range of 1: 1.0 to 1: 2.0, and particularly preferably in the range of 1: 1.0.
The range of 1.1 to 1: 1.25 is preferred. 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.

Subsequently, in the case of the second stage reaction, the polyvalent metal ion compound is added as it is or dissolved in a small amount of water in the above state. In this case, the added amount of the polyvalent metal ion compound is 0.5 to 1 mol of the starting tropolone.
1.01.0 mol, preferably 0.5-0.7 mol. When a polyvalent metal ion compound is added, the reaction system generally turns black,
Then heat, preferably refluxed (in a hot water bath)
The reaction is carried out at The reaction takes this state for 0.5-4.0 hours,
Maintaining it for preferably 1 to 2.5 hours almost completes.

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.

By the above reaction, a dithiotropolonate-based metal complex is obtained. When the tropolone represented by the general formula (I) and its derivative are used as a raw material, the metal complex represented by the following general formula (II) Is obtained.

(Wherein R ′ represents a hydrogen atom or an alkyl group;
Represents a polyvalent metal. Specific examples of the polyvalent metal M in the general formula (II) include:
Examples include polyvalent metals such as Cu, Zn, Cd, Pb, V, Mo, Mn, Fe, Co, Ni, Pd, Pt, As, and Si.

Among the dithiotropolonate-based metal complexes obtained by the method of the present invention, a bis (4-alkyldithiotropolonate) metal complex represented by the following general formula (III) is a novel substance.

(In the formula, R represents an alkyl group and M represents a polyvalent metal.) Specific examples of the polyvalent metal M in the general formula (III) are the same as those described with respect to the general formula (II). Cu, Zn,
Examples include polyvalent metals such as Cd, Pb, V, Mo, Mn, Fe, Co, Ni, Pd, Pt, As, and Si. Further, as the alkyl group R, a lower alkyl group having 1 to 5 carbon atoms is preferable, and an isopropyl group is particularly important from the viewpoint of availability of raw materials.

Representative specific examples of the compound represented by the general formula (III) of the present invention include those shown in Table 1, but the present invention is not limited thereto.

[Effect] As described above, the method of the present invention uses inexpensive tropolone and its derivatives as raw materials, and can easily and inexpensively obtain a dithiotropolonate-based metal complex by a two-step reaction, It can be said that this is an extremely advantageous production method. In addition, the bis (4-alkyldithiotropolonate) metal complex of the present invention is a novel substance, some of which have excellent near-infrared absorption properties, and are near-infrared absorbers or stabilizers for various organic materials. It is expected to be useful as such.

〔Example〕

Next, the present invention will be described in more detail with reference to examples. In addition, all the parts shown below are based on weight.

Example 1 Synthesis of bis (dithiotropolonate) copper complex 4.88 parts (0.04 mol) of tropolone and 10 parts of phosphorus pentasulfide (0.
(045 mol) was suspended in 45 parts of dioxane, and the mixture was heated under reflux and stirred for 2.5 hours. During this time, the reaction turned from orange to dark reddish brown. After the completion of the reaction, the reaction system was once cooled, and 3.99 parts of copper acetate [(CH ₃ COO) ₂ Cu · H ₂ O] (0.
02 mol) was dissolved in 15 parts of water and added to the reaction system.
The mixture was heated and stirred under reflux for 2 hours. After the reaction, the reaction system was cooled, and the precipitate was filtered off.
5.36 parts were obtained. When this crystal was recrystallized from toluene, a green-black crystal was obtained, and its melting point was 268 ° C. (decomposition), which coincided with the melting point of CEForbes and the like.

Example 2 Synthesis of bis (dithiotropoloneo) nickel complex 5.00 parts (0.0409 mol) of tropolone and 10.91 of phosphorus pentasulfide
Example 1 was suspended in 50 parts of dioxane.
The reaction was carried out for 3 hours according to 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, which appears to be a complex or ester of dithioltropolone and phosphorus sulfide, has yet to elucidate its structure. But, The following reactions were performed assuming the structure.

4.99 parts of the above compound were suspended in 50 parts of dioxane, and further dissolved in 3.57 parts of nickel chloride hexahydrate (0.015 mol) 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, the precipitate was separated by filtration, and black crystals 1.
18 copies were obtained. When this crystal was recrystallized from pyridine, the melting point of the obtained purified crystal showed 328 ° C (decomposition),
It was consistent with the melting point of CEForbes et al.

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

Example 3 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 are as follows, and its infrared absorption spectrum (KBr tablet method) was
Shown in the figure.

Example 4 Synthesis of bis (4-isopropyldithiotropolonate) palladium complex 16.41 parts (0.1 mol) of hinokitiol and 26.6 parts of phosphorus pentasulfide
Seven parts (0.12 mol) were suspended in 350 parts of dioxane, heated under reflux in a nitrogen gas atmosphere, and stirred for 5 hours. After the reaction, the reaction solution was allowed to cool, the precipitate was separated by filtration, and dried under reduced pressure to obtain 24.74 parts of reddish brown crystals. As a result, the compound was poorly soluble in toluene and 1,1-dichloroethane, and its melting point was 2
It showed sintering at 03 ° C and decomposition at 204-205 ° C. The crystals appeared to be a complex or ester of 4-isopropyldithioltropolone and phosphorus sulfide, but did not elucidate the structure. But, The following reactions were performed assuming the structure.

2.79 parts of the above compound were suspended in 20 parts of dioxane, and 1.33 parts (0.0075 mol) of palladium chloride was suspended in 10 parts of water and added. The mixture was stirred for 2 hours under reflux in a water bath. After the reaction, the reaction system was allowed to cool, and the precipitate was separated by filtration.
After washing with methanol, 2.66 parts of dark purple crystals were obtained. The melting point of the obtained crystals was 203-205 ° C. When the crystals were recrystallized from acetone, dark purple crystals having a melting point of 204 to 205 ° C were obtained.

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

Example 5 Synthesis of bis (4-isopropyldithiotropolonate) iron complex 5.59 parts of a hypothetical structure which is considered to be a 4-isopropyldithioltropolone-phosphorus sulfide complex or ester obtained as an intermediate in Example 4 was replaced with dioxane 50 Suspended in water, and 4.05 parts (0.015 mol) of iron chloride hexahydrate dissolved in 15 parts of water were added, and dark brown crystals were obtained in the same manner as in Example 4.
3.91 parts were obtained. The melting point of the obtained crystals was 252 to 257 ° C (decomposition). The crystals were recrystallized with a mixed solvent of 1,1-dichloroethane / acetone (mixing ratio 1/1).
Dark brown crystals of 54-255 ° C (decomposition) were obtained.

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

Example 6 Synthesis of bis (4-isopropyldithiotropolonate) cobalt complex According to Example 4, 5.59 parts of a hypothetical structure which is considered to be a 4-isopropyldithioltropolone-phosphorus sulfide complex or ester, 50 parts of dioxane and anhydrous The reaction was carried out using 1.95 parts (0.015 mol) of cobalt chloride, and 3.86 purple-black crystals were obtained.
Got a part. The melting point of the obtained crystals was 264 to 367 ° C.
When the crystals were recrystallized from acetone, the melting point was 265-2.
66 ° C. black crystals were obtained.

The elemental analysis values of the obtained purified cobalt complex are as follows, and its infrared absorption spectrum (KBr tablet method) is
Shown in the figure.

Table 2 shows the absorption characteristics and physical properties of the metal complex obtained by the method of the present invention, including the novel metal complex of the present invention, from the visible region to the near infrared region.

[Brief description of the drawings]

1 to 4 show infrared absorption spectra of the respective metal complexes obtained in Examples 3, 4, 5 and 6 of the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C07F 15/04 9450-4H C07F 15/06 15/06 8721-5D G11B 7/24 516 G11B 7 / 24 516 C09K 3/00 105 // C09K 3/00 105 15/10 15/10 B41M 5/26 Y (56) References Inorganic Chemistry, 1972, 11 (6), 1318-1323 Journal of the American Chemical. Society, 1968, 90 (24), 6884-6885 Jourhal of the American Chemical Society, 1970, 92 (8), 2297-2303 Jourhal of the American Chemical, 1971, 93 (15), 3597-3602

Claims (2)

(57) [Claims] 1. A process for producing a dithiotropolonate-based metal complex, comprising reacting a tropolone-based compound with phosphorus pentasulfide and then reacting the reaction product with a polyvalent metal ion. 2. A novel bis (4-) represented by the following general formula:
Alkyldithiotropolonate) metal complexes. (In the formula, R represents an alkyl group, and M represents a polyvalent metal.)