JPS63227597A - Bis(dithiobenzyl)nickel complex compound - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R is 1-10C alkyl). EXAMPLE:Bis(3,3',4,4',5,5'-hexabutoxydithiobenzyl)nickel. USE:An infrared rays absorbent, useful in shielding of heat radiation, growth control of plant, infrared rays cut-off filter of semiconductor light-receiving element, etc., and having high solubility to organic materials, excellent near- infrared ray-absorbing ability and deactivation performance of singlet oxygen. PREPARATION:A benzoin expressed by formula II and phosphorus pentasulfide are dissolved in a solvent such as dioxane and refluxed to subject the dioxane to sulfuration. Then the phosphorus pentasulfide is filtered from the reaction mixture and water solution of nickel salt expressed by the formula NiX2 is added to the filtrate containing a dissolved intermediate product to carry out reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel bis(dithiobenzyl)nickel complex compound.

[Conventional technology]

Bis(dithiobenzyl)nickel complex compounds (hereinafter abbreviated as complex compounds) generally exhibit remarkable absorption of near-infrared rays in the wavelength range of 800 to 9001 m, and have excellent performance as infrared absorbers. .

Therefore, the above-mentioned complex compound is useful for use as an infrared absorber, that is, for use that utilizes the property of absorbing near-infrared rays and converting the light energy into other physical energy such as heat or electricity.

The following are the main uses:

(1) Blocking of heat rays Of the sunlight, light in the infrared region with a wavelength of 800 nm or more is absorbed by objects and converted into thermal energy.

Therefore, by incorporating the above-mentioned complex compound that has a remarkable absorption ability in the near-infrared region into a transparent plastic, or by coating it on the surface of a transparent material such as glass using an appropriate means, a transparent material that can block heat rays can be made. Materials can be made. Specific applications include glasses and sunglasses that can protect the eyes from heat rays.

(2) Control of plant growth The fact that the growth and differentiation of plants is influenced by light has long been known as photomorphogenesis. By using a plastic film containing a complex compound to block near-infrared rays irradiated to a plant, its morphology can be controlled.

(3) In a photodetector used in an automatic exposure meter such as an infrared cut filter camera using a semiconductor light receiving element, a silicon photodiode is used as the light receiving element. By applying a complex compound to the surface of this light-receiving element and cutting off the infrared light that enters the light-receiving element, the spectral sensitivity of the light-receiving element can be brought close to the relative luminous sensitivity, which can cause exposure meter malfunctions. can be prevented.

(4) Another application that utilizes the property of absorbing light in the infrared region is a technology that prevents the copying of confidential documents by treating a sheet for confidential documents with the above-mentioned complex compound as an infrared absorbing agent. , a laminated electrophotographic photoreceptor using the above-mentioned complex compound as an infrared absorber as a charge generation layer (CGL layer), or a layered electrophotographic photoreceptor in which the infrared irradiated area is formed of a notation compound and changes in physical properties due to infrared irradiation are utilized. There are optical recording media, etc. that can be used for recording, and many other uses can be considered.

In addition to the above-mentioned infrared absorption performance, the complex compound also has an excellent deactivation effect against so-called doublet oxygen. Therefore, this complex compound is effective as an antioxidant and weathering agent for polyolefins and the like, and also as an anti-fading agent for preventing fading of organic dyes in color photographs and the like.

Furthermore, the above-mentioned complex compound can be used as a catalyst for water photolysis reactions and dehydration reactions, and as a liquid crystal material.

As explained above, the above complex compound has many excellent properties.

In order to fully exhibit the above properties, a desired amount of this complex compound is often added to the plastic.

It is important that they are evenly dissolved and contained in organic materials such as inks, paints, or organic solvents.

[Problem that the invention seeks to solve]

However, the above complex compounds generally have low solubility in organic materials. Therefore, a sufficient amount of the complex compound cannot be contained in the organic material as a product, and therefore, there is a problem that the excellent performance of the complex compound cannot be fully exhibited.

An object of the present invention is to provide a complex compound that has high solubility in organic materials.

Another object of the present invention is to provide a complex compound having excellent near-infrared absorption ability and singlet oxygen deactivation ability.

[Means for solving problems]

In order to achieve the above object, the inventor has conducted extensive research,
This completes the present invention.

That is, the present invention is a complex compound represented by the following general formula.

41 To explain the present invention in more detail, in the above general formula, it goes without saying that the alkyl group represented by R at C1 to C+a is not limited to a straight chain structure but may have a branched structure. Specifically, methyl, ethyl, n-propyl, n-
Buty, le, n-pentyl.

straight alkyl groups such as n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, 1-propyl,
Branched alkyl groups such as 1-butyl and 2-ethylhexyl can be mentioned.

The above complex compound can be prepared from benzoin by a known method (J, Am
Chem, Soc, Vol. 37, pp. 1483-1489, 1965).

That is, benzoin [■] having corresponding substituents and phosphorus trisulfide are dissolved in a solvent such as dioxane and refluxed for a predetermined period of time to sulfurize benzoin [■] to obtain an intermediate product. Thereafter, it is cooled and excess phosphorus trisulfide is filtered off.

After the intermediate product is dissolved, a nickel salt is added as an aqueous solution to the filtrate, and the reaction is carried out under predetermined conditions. Next, the target complex compound can be obtained by performing separation and purification.

In addition, when a normal complex compound undergoes a complex formation reaction with a nickel salt, the product precipitates as a crystal, so it can be easily separated and purified, but the complex compound according to the present invention has a high solubility, so it does not precipitate as a crystal. It was virtually impossible to separate and purify the product.

The reaction formula for the above synthesis process is as follows.

[■]

[Intermediate product] [Intermediate product] 10NlX2 [Example 1] Figure 1 is a graph showing the light absorption characteristics of the complex compound of Example 1, and Figure 2 is a graph showing the light absorption characteristics of the complex compound of Example 1. FIG. 3 is a graph showing the ability to deactivate singlet oxygen, and FIG. 3 is a graph showing the ability to inhibit photofading of the dye.

The complex compound of Example 1 is bis(3,
3', 4.4°, 5,5°-hexamethoxydithiobenzyl) nickel (hereinafter abbreviated as complex compound [■]).

First, the method for synthesizing the complex compound [■] will be explained.

Synthesis of benzoin> 3゜3, which is the raw material for the complex compound [II[) of Example 1]
”, 4,4°, 5,5′-hexamethoxybenzoin (IV) was prepared by a known method (J, Am, Chem, Soc,
67, p. 1606, 1945), according to the following reaction formula.

That is, 39.2 g (0.2 mol) of 3.4.5-trimethoxybenzaldehyde was dissolved in 95% ethanol 70-
The product is dissolved in a mixed solvent consisting of 40% of water and 40% of water, and 4g of sodium cyanide is added thereto, followed by a heating reaction under reflux for 3 hours.

After cooling to room temperature, the precipitated crystals are filtered off and washed with a small amount of ethanol and water to obtain a crude product. By recrystallizing and purifying this crude product from ethanol, 7 g (yield = 18%) of the target benzoin compound [rV] was obtained.

The melting point was 143-145.5°C.

Synthesis of complex compound [I[)] 3.9 g of benzoin compound (IV) obtained above (0,
01 mol) and 3.3 g (0,015 mol) of phosphorus trisulfide were suspended in 70% dioxane, and a heating reaction was carried out under reflux for 2 hours. After the reaction product is cooled to room temperature, the reaction product suspension is filtered to separate solids such as excess phosphorus trisulfide as a reaction residue. Approximately 10% of this solid matter
- This dioxane is also added to the above filtrate to make it a part of the filtrate.

To the above filtrate in which the intermediate product is dissolved, an aqueous solution obtained by dissolving 2.4 g (0.01 mol) of nickel chloride hexahydrate in 10% water is added, and then stirred at room temperature for about 15 hours. Continuation gives a crude product-containing solution consisting of a black solution. At this time, no precipitation of the product was observed, and separation and purification by recrystallization was not possible.

The solution containing the crude product was concentrated under reduced pressure using a rotary evaporator, and the concentrated solution was subjected to column chromatography for separation and purification. The column packing material was silica gel, and benzene was used as the developing solvent. As a result, 1.5 g (yield: about 33%) of the target complex compound [■] was obtained.

Next, the physical property values of the above complex compound [■] are shown.

'H-NMR (in CDCj!3) δ: 3.72 (8,24N>, 3.88 (3,121(
), 6.66 (S, 8H) Raman spectrum (in dichloromethane) v (S-N i) = 389.346
．． 153 (Cm-'] Elemental analysis: C2゜H44012
N i S 4 calculated values: C=53.16%, H=
4.91% Actual value: C=52.67%, H=4.
89% solubility -4.43 wt% (in benzene at 25°C) Here, ν(S-Ni) represents the absorption wave number of the Raman spectrum due to the 5-Nl bond.

Note that the solubility of the complex compound CI[[) in benzene (25° C.) is 4.4 wt% as described above.

This value is approximately 30% of the solubility (0.15 wt% under the same conditions) of bis(4,4"-dimethoxydithiobenzyl)nickel (V) of the following formula, which has a methoxy group only at the 4.4"-position.
It's double.

The fact that the solubility is extremely high as described above is shown in Example 1.
This is one of the major features of complex compound (I). Although only the solubility in benzene is shown here, it goes without saying that it also has high solubility in commonly used solvents such as dioxane, ethanol, or n-hexane.

The fact that it has high solubility in organic solvents as described above is considered to mean that it is easily soluble in organic materials constituting plastics, inks, paints, and the like. Therefore, since the complex compound of Example 1 can be contained in an organic material at a high concentration, the excellent performance of the compound can be fully exhibited. Further, since it can be prepared as a highly concentrated solution, a layer made of the above complex compound [I[] can be easily formed on the substrate by applying the solution onto the substrate.

Next, the properties of infrared absorption, doublet oxygen deactivation, and dye fading prevention that the complex compound CI[I] of Example 1 has will be explained.

Infrared absorption performance> FIG. 1 shows the absorbance curve of complex compound [III) for light from the visible region to the near-infrared region. Dichloromethane was used as the measurement solvent.

Below is the maximum absorption wavelength λ (+nax) in the near-infrared region
and its molar extinction coefficient ε(max).

λ(max) = 870 Cnm)ε(max>
-20850C1l -modo''cm-weight] As described above, the complex compound of this example has excellent absorption ability in the near-infrared region, and is therefore effective as an infrared absorber.

<-Doublet oxygen deactivation performance> FIG. 2 is a graph showing the deactivation effect of complex compound CIII) on -heavyt oxygen. Specifically, as shown in the following formula, when 2,5-dimethylfuran (VI) is reacted with heavyt oxygen 102 and then further reacted with methanol, 2,5-dimethyl-2-hydroperoxy-5
-methoxy-2,5-dihydrofuran [■] (hereinafter referred to as
We investigated the reaction that produces peroxide (abbreviated as ■).

[■] [■
] In the graph, the vertical axis shows the amount of peroxide [■] produced, and the horizontal axis shows the amount of complex "compound CI [[)" added at the initial stage of the reaction. In addition, in actual measurement, 0.01
0.03 mol of singlet oxygen was allowed to act on mol of 2,5-dimethylfuran [■]. This -heavyt oxygen is obtained by adding sodium hypochlorite Na0cj to hydrogen peroxide solution! It is chemically generated by the action of

Next, the measurement method will be explained in detail.

In a 300-nitro flask, add the specified concentration &(1,OX 1
0-'~5. 40 ml of dichloromethane solution of complex compound CI) adjusted to OX 10-3 mol dm-')
1, methanol 110- and 30% hydrogen peroxide solution 4- were added thereto, and 2,5-dimethylfuran Ig (0.01 mol) was added thereto. This solution was cooled to 0°C. Sodium hypochlorite aqueous solution 20, which was later standardized
ml was added dropwise over 90 minutes. Thirty minutes after dropping, the product was extracted by adding diethyl ether 50, and the organic layer was separated and concentrated under reduced pressure at low temperature to remove the solvent from the organic layer.

Excess methanol was added to the residue to produce 2,5-dimethyl-2-hydroperoxy-5-methoxy-2,5-dihydrofuran [■], and the methanol solution was concentrated under reduced pressure to form peroxide. [■] was obtained as a solid. The melting point was 75-76°C.

In addition, in the system in which complex compound [III) was not added, the conversion rate to peroxide [■] was 83%.

From the graph of FIG. 1, it can be seen that as the concentration of complex compound CI) increases, the amount of peroxide [■] produced decreases, and the reaction is suppressed.

As described above, the complex compound [■] of Example 1 has excellent deactivation performance against -stagnant oxygen.

Figure 3 shows the results of tracking the decomposition rate of methylene blue over time when it was irradiated with light, with and without the addition of the complex compound [II[)]. It is. The vertical axis represents the decomposition rate (%), the horizontal axis represents the irradiation time, and the mark Q represents the case where the complex compound (Illr) is not added, and the mark X represents the case where it is added.

Next, a specific measurement method will be explained.

2. Methylene Blue (Beige, Tsuku Blue 9: Color Index). OX l O-' [mol・12-
) Dichloroethane solution (1) and the solution has a concentration of 2.
．． A solution (2) was prepared by adding the complex compound [■] so that OX '10 to 5 (mol·!-1) was added.

Each of the above solutions was placed in a 4-sized UV cell, and the cell holder was mounted so that the temperature during light irradiation was adjusted to 25°C±0.5°C. At this time, the distance between the UV cell and the light source is approximately 3
It was Cm.

Then, each solution was irradiated with light from outside the UV cell using a 100W high-pressure mercury lamp (manufactured by Ushio Inc.). At that time, light in the wavelength range of 390 nm or less was filtered out.

FIG. 3 shows the degree of photofading of methylene blue as the decomposition rate (%) of methylene blue after irradiation with light, and this decomposition rate was calculated from the results of spectroscopic analysis using a spectrophotometer.

As is clear from FIG. 3, the complex compound of Example 1 (
III) was found to have a remarkable effect of suppressing photodecomposition of methylene blue, that is, photofading.

[Example 2] The following formula is the screw (3, 3", 4, 4°, 5,
5''-hexabutoxydithiobenzyl)nickel (hereinafter abbreviated as complex compound [■]).

The above complex compound [■] was synthesized as follows.

First, 3.3 g (0,005 mol) of 3,3°, 4,4°, 5,5'-hexabutoxybenzoin synthesized in the same manner as in the case of the benzoin compound [) of Example 1 and phosphorus trisulfide were added. 17 g (0,0077 mol) and geo=
16- Ksan 50m1! and heated under reflux for 2 hours. After cooling to room temperature, the reaction solution was filtered, and the residue was washed with about 10-dioxane, which was used as a part of the filtrate.

Add 1.2 g (0,005 g) of nickel chloride hexahydrate to the above filtrate.
After adding a solution obtained by dissolving 5-mol) in water, stirring was continued at room temperature for 15 hours, resulting in a black solution. This solution was concentrated under reduced pressure on a rotary evaporator to obtain a crude product. This crude product was purified by column chromatography using silica gel as a packing material and benzene as a developing solvent.

As a result, 1.2 g (17% of the theoretical yield) of the above complex compound [■] was obtained.

The complex compound [■] of Example 2 was subjected to the same performance test as in Example 1, and it was found that the complex compound [III
) showed almost the same performance.

° [Example 3] The following formula is the screw (3,3", 4,4°, 5,
5°-hexadecyloxydithiobenzyl)nickel (hereinafter abbreviated as complex compound CIX).

The complex compound [■] of Example 3 is 3.3° of the raw material.

4.4',5.5''-hexadecyloxybenzoin 1.
15 g (0,001 mol) and 0.33 g (0.33 g) of phosphorus trisulfide (
0,0015 mol) of nickel chloride was suspended in 30% dioxane, and 0.24 g (0,001 mol) of nickel chloride was dissolved in 1% of water. It was synthesized in almost the same manner as in case 2. Yield is 0.1
The yield was 7% of theory at 7 g.

Complex compound [IX] of Example 3 was also subjected to a performance test taking into account the nickel content.
It showed almost the same performance as the complex compound (III).

Although the present invention has been specifically described above based on Examples, the present invention is not limited to what is shown in the Examples.

For example, the types of substituents introduced into the phenyl nucleus are not limited to methoxy, n-butoxy, or n-tesyloxy groups, and the positions at which they are introduced are not limited to the 3-, 4-, and 5-positions.

In addition, in the explanation of the prior art, the use of bis(dithiobenzyl)nickel was specifically shown, but it is obvious that the complex compound [I) of the present invention is effective when applied to the above-mentioned use. In particular, it goes without saying that the present invention can be applied to any application that utilizes the properties of the complex compound CI).

〔Effect of the invention〕

Bis(dithiobenzyl)nickel is represented by the general formula:
The structure is made of plastic.

The solubility of organic materials such as inks, paints, and solvents can be greatly improved.

Furthermore, the above-mentioned bis(dithiobenzyl)nickel has remarkable absorption ability in the near-infrared region, and is therefore extremely effective as an infrared absorber. Therefore, it can be applied to various uses as an infrared absorbing agent, such as blocking heat rays, controlling plant growth, filtering light-receiving elements, preventing copying of confidential documents, laminated electrophotographic photoreceptors, and optical media.

Moreover, the bis(dithiobenzyl)nickel has a strong deactivating action against -stagnant oxygen, and is therefore effective as an antioxidant and a weathering agent.

Furthermore, since the bis(dithiobenzyl)nickel has the effect of suppressing photodecomposition of dyes, it is also effective as an agent for preventing fading of dyes.

Furthermore, since the bis(dithiobenzyl)nickel of the present invention has excellent solubility in organic materials as described above, it can be contained in a sufficient amount in the organic materials. The properties such as infrared absorption, oxidation prevention, and prevention of photofading of pigments can be fully demonstrated.

[Brief explanation of the drawing]

Figure 1 is a graph showing the light absorption properties of the complex compound of Example 1, Figure 2 is a graph showing the singlet oxygen deactivation ability of the above compound, and Figure 3 is the graph showing the ability to inhibit photofading of the dye. This is a graph showing.

Claims (2)

[Claims] (1) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R is an alkyl group of C_1 to C_1_0)
Bis(dithiobenzyl)nickel complex compound represented by (2) The bis(dithiobenzyl)nickel complex compound according to claim 1, wherein the RO group is located at the 3rd, 4th, or 5th position of each phenyl group.