JPH07242659A - Diarylethene compound having conjugated double bond chain - Google Patents

Abstract

PURPOSE:To obtain a new compound having such photochromic characteristics as to be excellent in thermal stability, the repetition stability for color development/color vanishment, semiconductor laser sensitivity and general sensitivity, etc., thus suitable for reversible optical recording materials, etc. CONSTITUTION:The objective compound is represented by formula I [(n) is 2-5; A is of formula II (R<1> is an alkyl or n alkoxyl; R<2>-R<5> each is H, an alkyl or an alkoxyphenyl); B is formula III (R<6> and R<7> each is an alkyl)], e.g. 1-[6-(4- methoxyphenyl)-2-methyl-3-benzothienyl]-2-{2,4-dimethyl-5-[4-(4-methox yphenyl)-1,3- butadienyl]-3-thienyl}-3,3,4,4,5,5-hexafluorocyclopentene. This compound of formula I can be obtained, for example, by simultaneous reaction between a perfluorocycloalkene derivative of formula IV and aryllithium derivatives ALi and BLi.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel diarylethene compound, and more particularly to a diarylethene compound having photochromic properties and suitable for optical recording materials and the like.

[0002]

2. Description of the Related Art Hue is reversibly changed by light irradiation,
So-called photochromic compounds have been known for a long time, and various recording / memory materials, copying materials, light control materials, masking materials, photometers, display materials and the like using these have been proposed. As these photochromic compounds, for example, compounds such as benzospiropyrans, naphthoxazines, fulgides, diazo compounds and diarylethenes have been proposed. In recent years, vigorous studies have been conducted to utilize such photochromic compounds as reversible optical recording materials, but the following basic performances are required for application to optical recording materials.
That is, recording stability, repetitive durability, semiconductor laser sensitivity, high sensitivity and the like. However, many of the currently known photochromic compounds are thermally unstable in either the colored state or the decolored state and return to a stable state within a few hours even at room temperature. It has a drawback that the stability cannot be secured. Among them, fulgides and diarylethenes are known as compounds whose two states are relatively thermally stable by irradiation with light, but their stability is still insufficient for use as a recording material. It has one of the drawbacks such as poor repetitive durability, poor sensitivity to semiconductor lasers, and low sensitivity (molecular extinction coefficient), and a photochromic compound that satisfies all performances has not yet been obtained. Is the reality.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to obtain thermal stability in a colored state, repeated durability, semiconductor laser sensitivity, sensitivity ( (EN) A novel diarylethene compound having excellent properties as a photochromic material such as a molecular extinction coefficient).

[0004]

The above-mentioned object can be achieved by a diarylethene compound having a conjugated double bond chain represented by the following general formula (1).

[Chemical 4] (However, in the formula, n, A and B are the same as above.)

Next, the present invention will be described in detail. The diarylethene compound of the present invention is represented by the above general formula (1), n is an integer of 2 to 5, and has a 4- to 7-membered ring cyclic structure in cooperation with a double bond. Among them, n is 3 or 4
The 5- or 6-membered ring structure of 1 shows particularly preferable photochromic properties. A represents a benzothienyl group represented by the general formula (2). R ¹ represents an alkyl group or an alkoxy group, and among them, a lower alkyl group or an alkoxy group such as a methyl, ethyl or propyl group is preferable. Also, R ²
To R ⁵ represent a hydrogen atom, an alkyl group or an alkoxyphenyl group. B represents a thienyl group having a conjugated double bond chain represented by the general formula (3). R ⁶ and R ⁷ represent an alkyl group, and among them, a lower alkyl group such as methyl, ethyl and propyl group is preferable. Thus, by introducing a conjugated double bond chain into the thiophene ring and an alkoxyphenyl group into the benzothiophene ring, among them, a methoxyphenyl group or an alkoxy group, among others, by introducing a methoxy group, the absorption maximum wavelength of the colored body is Longer wavelength, oscillation wavelength 67
A semiconductor laser sensitivity of 0 nm or 780 nm is imparted. Furthermore, the introduction of a conjugated double bond chain into the thiophene ring can increase the molecular extinction coefficient of the compound.

The diarylethene compound of the present invention can be produced by appropriately selecting from known methods, for example, the following method. That is, the following general formula (4)

[Chemical 5] (However, in the formula, n represents an integer of 2 to 5) and aryllithium derivatives ALi and BLi (A and B are the same as described above) at the same time, or ALi or BL.
Among i (A and B are the same as above), one of the monoarylethene derivatives, which has been reacted first, and the other aryllithium derivative, are reacted to form a diarylethene compound.

The following is an example of a preferred manufacturing method. That is, first, a benzothienyl halide derivative or a thienyl halide derivative represented by AX or BX (wherein, X represents a bromine atom or an iodine atom, and A and B are the same as described above) at a reaction temperature of −45 to − 120
C., preferably at -70 to -110.degree. C. to react with alkyllithium or lithium dialkylamide to obtain a lithiated benzothiophene derivative or a lithiated thiophene derivative in which the halogen atom at the 3-position is substituted with lithium.

As the solvent, ether type solvents such as tetrahydrofuran and diethyl ether are preferably used, but in order to prevent solvent coagulation at low temperature, n-hexane and n-hexane are used.
-Lower alkanes such as pentane may be mixed. Examples of alkyllithium and lithium dialkylamide as lithiating agents include n-butyllithium, t-butyllithium,
Methyl lithium, phenyl lithium, lithium diisopropyl amide, lithium dicyclohexyl amide, etc. are mentioned, and the hexane solution of n-butyl lithium is used suitably. The amount of the lithiating agent is preferably 1.0 to 1.2 times mol based on the total amount of the halogenated benzothiophene derivative. The reaction time is usually 20 minutes to 3 hours, preferably 30 minutes to 2 hours.

Next, the perfluorocycloalkene derivative represented by the general formula (4) is added to the lithiated benzothiophene derivative or the lithiated thiophene derivative thus produced. The amount of the perfluorocycloalkene derivative used is preferably 1.0 to 1.5 times the mol of the halogenated benzothiophene derivative or the halogenated thiophene derivative, and is added undiluted or diluted with a solvent. The reaction temperature is preferably -60 to -110 ° C, and the reaction time is preferably 30 minutes to 2 hours. After the above operation, the following general formula (5)

[Chemical 6] (However, in the formula, n and R ^{1 to} R ⁵ are the same as above.) Or a monobenzothienylethene derivative represented by the following general formula (6).

[Chemical 7] (However, in the formula, n, R ⁶ and R ⁷ are the same as described above.) A monothienylethene derivative is obtained.

The obtained monoarylethene derivative is A
A benzothienyl halide derivative or a thienyl halide derivative represented by X or BX (wherein A and B are the same as above, X represents a bromine atom or an iodine atom), and a lithiated benzothiophene derivative by the same method as described above. Alternatively, as a lithiated thiophene derivative, a solution of the above-mentioned monothienylethene derivative in terahydrofuran is added to the lithiated benzothiophene derivative, and a solution of the above-mentioned monobenzothienylethene derivative in terahydrofuran is added to the lithiated thiophene derivative. . The amount of the monobenzothienylethene derivative or the monothienylethene derivative used is preferably 1.0 to 1.2 times mol of the benzothienyl halide derivative or the thienyl halide derivative. At this time, the reaction temperature is preferably −60 to −110 ° C., and the reaction time is preferably 30 minutes to 2 hours. In order to obtain the diarylethene compound from the reaction product obtained by the above method, it may be separated and purified by a method such as extraction, column chromatography, recrystallization and the like.

The diarylethene compound of the present invention is, for example, 1- (6- (4-methoxyphenyl)-
2-Methyl-3-benzothienyl) -2- (2,4-dimethyl-5- (4- (4-methoxyphenyl) -1,3
-Butadienyl) -3-thienyl) -3,3,4,4,
Explaining 5,5-hexafluorocyclopentene, in an appropriate medium such as an organic solvent or an appropriate resin binder, as shown by the following formula (7),

[Chemical 8] When the opened ring is irradiated with ultraviolet light, it changes to a closed ring and is colored.
When this closed ring is irradiated with visible light, it returns to the original open ring,
Erase.

An optical recording material using a recording medium containing the diarylethene compound of the present invention can be easily obtained by a known method. For example, a method of depositing the diarylethene compound of the present invention on a suitable substrate by a known vapor deposition method, or a method of depositing the diarylethene compound of the present invention in a polyester resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate polyvinyl butyral Resin, polymethylmethacrylic acid resin, poly-t-butylmethacrylic acid resin, polycyclohexylmethacrylic acid resin, polycarbonate resin, phenol resin, epoxy resin and other resin binders, together with benzene, toluene, xylene,
Hexane, cyclohexane, methyl ethyl ketone, acetone, methanol, ethanol, tetrahydrofuran,
Dioxane, carbon tetrachloride, chloroform, cellosolve,
An optical recording material is prepared by dispersing or dissolving it in a solvent such as diglyme and coating it on a suitable substrate, or by dissolving the diarylethene compound of the present invention in a solvent as described above and coating it on a suitable substrate. Can be obtained.

In such an optical recording material, the diarylethene compound of the present invention has high thermal stability in both a colored state and a decolored state, is stable to moisture, oxygen and the like and changes its structure for a long period of time. It is retained without being used, and has excellent durability against repeated wear and removal of colors. The maximum absorption wavelength in the colored state is 600n.
Since it has a wavelength of m or more and an absorption edge of 800 nm or more, it has sensitivity to a semiconductor laser having an oscillation wavelength of 670 nm or 780 nm, and has high sensitivity in that wavelength region (having a large molecular absorption coefficient). )
Since it has excellent photochromic characteristics such as,
It can be effectively used for reversible optical information recording materials and the like.

[0014]

INDUSTRIAL APPLICABILITY As described above, the diarylethene compound of the present invention has excellent photochromic properties such as thermal stability, repeated durability of color fading and decoloring, sensitivity to semiconductor laser, sensitivity, etc. It can be used for various purposes such as recording materials. Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Example 1) 1- (6- (4-methoxyphenyl) -2-methyl-3
-Benzothienyl) -2- (2,4-dimethyl-5-
Preparation of (4- (4-methoxyphenyl) -1,3-butadienyl) -3-thienyl) -3,3,4,4,5,5-hexafluorocyclopentene

A) 1- (6- (4-methoxyphenyl)
-2-methyl-3-benzothienyl) -2,3,3,
Production of 4,4,5,5-heptafluorocyclopentene In a 1000 ml capacity two-necked flask, 3-bromo-6 was added.
After adding 20.0 g (60 mmol) of-(4-methoxyphenyl) -2-methylbenzothiophene and 600 ml of tetrahydrofuran and cooling to -95 ° C under a nitrogen stream, n
-Butyl lithium-hexane solution 45.0 ml (72 m
(mol) and the mixture was stirred for 1 hour. Next, 90 ml of a tetrahydrofuran solution containing 18.8 g (90 mmol) of perfluorocyclopentene was added dropwise, and the mixture was reacted for 1 hour. After the reaction was completed, 40 ml of methanol was added to stop the reaction, 200 ml of water was further added, and then 400 ml of ethyl acetate was added.
The mixture was extracted 3 times with ml, the organic layers were collected, washed and dried, and the solvent was evaporated under reduced pressure. The obtained reaction product was purified by silica gel column chromatography to obtain 22.1 g of a compound represented by the following structural formula (Formula 9). (Yield 82.5
%)

[Chemical 9]

Analytical value: 1) MS m / e 446 (M ⁺ ).

B) Preparation of 2,4-dimethyl-5- (2-formyl-1-ethenyl) -3-iodothiophene 2,4-Dimethyl-5-formyl-3-in a 100 ml capacity two-necked flask. 3.3 g of iodothiophene (1
2.5 mmol) formyl methylene triphenylphosphorane 4.6 g (15.0 mmol), toluene 40 ml
Was charged and refluxed for 120 hours to react. After the reaction, the solvent was distilled off under reduced pressure, diethyl ether was added to the residue, and the insoluble matter was filtered off. The solvent of the filtrate was distilled off under reduced pressure, and the obtained reaction product was purified by silica gel column chromatography to obtain 3.0 g of a compound represented by the following structural formula (Formula 10). (Yield 82.2%)

[Chemical 10]

Analytical values: 1) ¹ H-NMR (in CDCl ₃ ) δ (ppm) 2.50 (s 3H) 5.80 to 8.2
2 (m 5H) 9.58, 9.79 (d 1H) 2) MS m / e 292 (M ⁺ ).

C) 2,4-dimethyl-5- (4- (4-
Production of methoxyphenyl) -1,3-butadienyl) -3-iodothiophene In a two-necked flask having a capacity of 100 ml, 8.4 g (2) of 4-methoxybenzyltriphenylphosphonium chloride.
0.0 mmol), prepared in Example 1-b), 2,
4-dimethyl-5- (2-formyl-1-ethenyl)-
2.9 g (10.0 mmol) of 3-iodothiophene,
Sodium carbonate 8.8g, formamide 1.9g, 1,
4-dioxane (50 ml) was added and the mixture was refluxed for 24 hours for reaction. After the reaction, the insoluble matter was filtered off, the solvent of the filtrate was distilled off under reduced pressure, diethyl ether was added to the residue, and the insoluble matter was filtered off. The solvent of the filtrate was distilled off under reduced pressure, the obtained reaction product was purified by silica gel column chromatography,
3.5 g of the compound having the following structural formula (Formula 11) was obtained. (Yield 88.3%)

[Chemical 11]

Analytical value: 1) ¹ H-NMR (in CDCl ₃ ) δ (ppm) 2.26 (s 3H) 2.40 (s
3H) 3.70 (s 3H) 6.20 to 7.61 (m 8)
H) 2) MS m / e 396 (M ⁺ )

D) 1- (6- (4-methoxyphenyl)
-2-Methyl-3-benzothienyl) -2- (2,4-
Dimethyl-5- (4- (4-methoxyphenyl) -1,
3-butadienyl) -3-thienyl) -3,3,4
Production of 4,5,5-hexafluorocyclopentene In a two-necked flask having a capacity of 200 ml, 2,4-dimethyl-5- (4- (4-methoxyphenyl) -1,2, produced in Example 1-c) was used. 3.2 g (8.0 mmol) of 3-butadienyl) -3-iodothiophene and 80 ml of tetrahydrofuran were added, and the mixture was cooled to −95 ° C. under a nitrogen stream,
6.0 ml of n-butyllithium-hexane solution (9.6
(mmol) and the mixture was stirred for 1 hour. Then, 1- (6- (4-methoxyphenyl) -2-methyl-3-benzothienyl) -2,3, prepared in Example 1-a).
8 ml of a tetrahydrofuran solution containing 3.8 g (8.0 mmol) of 3,4,4,5,5-heptafluorocyclopentene was added dropwise and reacted for 1 hour. After the reaction was completed, 5 ml of methanol was added to stop the reaction, 20 ml of water was added, and the mixture was extracted 3 times with 100 ml of ethyl acetate. The organic layers were collected, washed and dried, and then the solvent was distilled off under reduced pressure. The obtained reaction product was purified by silica gel column chromatography to obtain 4.2 g of a diarylethene compound represented by the following structural formula (Formula 12). (Yield 74.6%)

[Chemical 12]

Analytical value: 1) ¹ H-NMR (in CDCl ₃ ) δ (ppm) 1.90 (s 1H) 2.15 (s
1H) 2.34 (s 1H) 3.64 (s 1H) 3.67 (s 1H) 5.70 to 8.00 (m 5)
H) 2) MS m / e 696 (M ⁺ ).

Example 2 1- (2-methoxy-3-benzothienyl) -2-
(2,4-dimethyl-5- (4- (4-methoxyphenyl) -1,3-butadienyl) -3-thienyl) -3,
Production of 3,4,4,5,5-hexafluorocyclopentene a) 1- (2-methoxy-3-benzothienyl)-
Production of 2,3,3,4,4,5,5-heptafluorocyclopentene A 2-necked flask having a capacity of 1000 ml was charged with 6.6 g (40 mmol) of 2-methoxybenzothiophene and 400 ml of diethyl ether under a nitrogen stream. , At room temperature, 30.0 ml of n-butyllithium-hexane solution (48 mmo
1) was added dropwise and the mixture was stirred for 12 hours. Next, after cooling to −95 ° C., 4.2 g of perfluorocyclopentene (40 m
40 ml of a tetrahydrofuran solution of
The reaction was carried out for 2 hours. After the reaction was completed, 40 ml of methanol was added to stop the reaction, 200 ml of water was added, and the mixture was extracted 3 times with 400 ml of ethyl acetate, and the organic layers were collected,
After washing and drying, the solvent was distilled off under reduced pressure. The obtained reaction product was purified by silica gel column chromatography to obtain 11.8 g of a compound represented by the following structural formula (Formula 13).
(Yield 82.5%)

[Chemical 13]

Analytical value: 1) MS m / e 356 (M ⁺ )

B) 1- (2-methoxy-3-benzothienyl) -2- (2,4-dimethyl-5- (4- (4-methoxyphenyl) -1,3-butadienyl) -3-thienyl) Preparation of -3,3,4,4,5,5-hexafluorocyclopentene 1- (6- (4-methoxyphenyl) -2-methyl-3-benzothienyl) in the paragraph d) of Example 1 -2
Instead of using 3,3,4,4,5,5-heptafluorocyclopentene 1 prepared in Example 2 a)
-(2-Methoxy-3-benzothienyl) -2,3
Using 3,4,4,5,5-heptafluorocyclopentene, 2.8 g of a diarylethene compound represented by the following structural formula (Formula 14) was obtained by the same method. (Yield 52.6%).

[Chemical 14]

Analytical value: 1) ¹ H-NMR (in CDCl ₃ ) δ (ppm) 2.00 (s 1H) 2.22 (s
1H) 3.78 (s 1H) 3.81 (s 1H) 6.20 to 7.85 (m 4H) 2) MS m / e 606 (M ⁺ ).

<Measurement of Absorption Spectrum> The compounds obtained in Examples 1 and 2 were added to benzene at 2.2 × 10 ⁻⁵ , respectively.
The solution obtained by dissolving so as to have a mol / l of 1.8 × 10 ⁻⁵ mol / l was put into a 1 cm × 1 cm × 4 cm quartz glass cell. Attaching a glass filter to this 10
The solution was colored by irradiating it with light having a wavelength of 365 nm until it was saturated and colored using a 0 W ultra-high pressure mercury lamp with stirring, and then the absorption spectrum of the solution in the photo steady state was measured. For the compounds obtained in Examples 1 and 2, 365n
The absorption spectra of the colored body and the decolorized body which are saturated by the light of m are shown in FIGS. Further, this coloration / decoloration reaction could be carried out reversibly. Next, with respect to the compounds of Examples 1 and 2, Table 1 shows the absorption maximum wavelength (λmax) of the colored body produced by saturation with light of 365 nm and the molecular absorption coefficient (ε · λmax) of the compound at this maximum wavelength. Show.

[0029]

[Table 1]

As described above, the absorption maximum wavelength of the colored product is long by introducing the conjugated double bond chain into the thiophene ring and introducing the methoxyphenyl group into R ⁴ or the methoxy group into R ^{1 of} the benzothiophene ring. Wavelength, oscillating wavelength 670 nm,
Alternatively, a semiconductor laser sensitivity of 780 nm was imparted. Furthermore, by introducing a conjugated double bond chain into this thiophene ring, the molecular extinction coefficient of the compound could be increased.

[Brief description of drawings]

FIG. 1 is a graph showing changes in absorption spectrum of the compound obtained in Example 1 upon light irradiation in a benzene solution.

FIG. 2 is a graph showing changes in absorption spectrum of the compound obtained in Example 2 upon irradiation with light in a benzene solution.

Claims (1)

[Claims] 1. A diarylethene compound having a conjugated double bond chain represented by the following general formula (1). [Chemical 1] (However, in the formula, n represents an integer of 2 to 5. A is a general formula (2) The stands, R ¹ represents an alkyl group, an alkoxy group, R ² to R ⁵
Represents a hydrogen atom, an alkyl group or an alkoxyphenyl group. B is represented by the general formula (3): And R ⁶ and R ⁷ represent an alkyl group. )