JP2565734B2 - Photochromic fluorescent dye - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention has both a photochromic site that exhibits a reversible structural change upon photostimulation and a site that emits fluorescence upon irradiation with light, and that the photochromic site is exposed to light. The present invention relates to a photochromic fluorescent dye in which the wavelength of fluorescence also reversibly changes with the structural change of the molecule due to isomerization.

(Prior Art) With the progress of optoelectronics, fluorescent molecules are becoming more important as materials for wavelength conversion elements. The term "fluorescence" as used herein refers to a phenomenon in which light of a certain wavelength is emitted to emit light of another wavelength. This phenomenon is also the function of converting the wavelength of light. Fluorescent dyes that reversibly change the fluorescence wavelength in response to light or electricity signals are expected to be applied to optical switches, optical memories, displays and the like. A wide variety of fluorescent dyes have been known so far, but a fluorescent dye capable of reversibly changing the fluorescence wavelength in response to an optical signal as described above has not yet been known.

(Problems to be Solved by the Invention) The present invention aims to provide a novel fluorescent dye which has not been known so far, and utilizes the fact that the photochromic moiety exhibits a structural change due to photoisomerization. The present invention provides a photochromic fluorescent dye capable of reversibly changing the fluorescence wavelength in response to an optical signal.

(Means for Solving the Problems) The present invention comprises a compound represented by the following general formula (I) or (II) having a photochromic moiety composed of a thioindigo skeleton and two moieties having a fluorescent function, and a photochromic moiety It is a photochromic fluorescent dye capable of changing the fluorescence wavelength by photoisomerization of.

However, in the general formulas (I) and (II), -X ¹ -R ¹
And -X ² -R ² are each 7,7 'position, 4,4' located in position or 4,7 'position, X ¹ and X ² may be the same or different, -COO -, - CONH-, -OCO-, -NHCO-, -O
_{-, - CH 2 O -,} - CO- and -CH ₂ - represents a group selected from an organic group that emits good fluorescence even R ¹ and R ² have the same or different.

The fluorescent dye of the present invention is a substance integrating an external stimulus response function, and is a substance in which a photoresponsive photochromic site is introduced into a fluorescent molecule as a means for reversibly changing the fluorescence wavelength in response to an optical signal. The structural change of the photochromic site affects the fluorescent site and changes the fluorescence wavelength. Photochromism is a phenomenon that shows reversible structural changes in response to light stimulation.

In the fluorescent dye of the present invention, the thioindigo skeleton exhibits transcisic photoisomerization. The substitution positions of the two fluorescent substituents R ¹ and R ² are represented by the following structural formulas. It is 7,7 'position, 4,4' position or 4,7 'position (same as 7,4' position) of the thioindigo skeleton shown by. Two fluorescent substituents R ¹ and R ² are represented by the following general formulas (I ′) and (II ′):
When the thioindigo skeleton is at the 7'position and the thioindigo skeleton is in the trans form as in the general formula (I '), these substituents cannot come close to each other and thus emit a monomeric light. On the other hand, when the thioindigo skeleton is in the cis form as in the general formula (II ′),
Since these substituents are close to each other, they exhibit excimer light emission. Excimer light emission is a phenomenon in which one substituent is photoexcited, a dimer is formed with the other unexcited substituent, and fluorescence is emitted. This phenomenon occurs when the two substituents of the general formula (II ') are the same or different, and the light emission due to the dimer formation of the different substituents is called exciplex light emission.

When the two fluorescent substituents are substituted at the 4,4 'position, monomeric emission is shown when the thioindigo skeleton is in the trans form, and excimer emission is obtained when the thioindigo skeleton is in the trans form, as in the case of the 7,7' position substitution. It exhibits sexual luminescence (or exciplex luminescence). In the case of substitution at the 4,7 'position (same as 7,4' position), R ¹
The two substituents of R and R ² are easily accessible in the trans form and exhibit excimer emission (or exciplex emission). In the case of the cis form, R ¹ and R ² are not easily accessible, and thus the monomeric emission is not achieved. Show.

In the fluorescent dye of the present invention, various known groups can be mentioned as the group corresponding to the site having a fluorescent function,
In particular, a condensed ring aromatic hydrocarbon group or a methyl, halogen, nitro, amino, dimethylamino, cyano-substituted product thereof or a nitro, amino, dimethylamino, dicyano-substituted phenyl group is preferable. Specific examples of these include pyrene, anthracene, phenanthrene, naphthalene, benzo (a) anthracene, naphthacene, perylene, triphenylene, chrysene, benzo [c] phenanthrene, coronene, methylnaphthalene, fluoronaphthalene, bromonaphthalene, chlornaphthalene, iodo. Examples thereof include naphthalene, nitronaphthalene, aminonaphthalene, cyanonaphthalene, dimethylaminonaphthalene, nitrobenzene, diaminobenzene, dicyanobenzene and dimethylaminobenzene.

Specific examples of the organic compound that can be the photochromic fluorescent dye of the present invention include dipyrenylthioindigo-7,
7'-dicarboxylic acid amide, dianthranylthioindigo-7,7'-carboxylic acid amide, dianthranylthioindigo-7,7'-carboxylic acid ester, thioindigo-
7-carboxylic acid pyrenyl amide-7'-carboxylic acid-p
-Cis isomers such as -nitrophenylamide, thioindigo-7-carboxylic acid anthranilamide-7'-carboxylic acid-p-nitrophenylamide, thioindigo-7-carboxylic acid anthranilamide-7'-carboxylic acid dicyanophenyl ester Is mentioned.

The fluorescent dye of the present invention is produced using a carboxylic acid body, a hydroxy body, an amino body or a chloromethyl body substituted at the corresponding position of the thioindigo skeleton as a raw material. For example, when X ¹ or X ^{2 in} the general formula (I) is —COO— or —CONH—, it can be obtained by a condensation reaction between thioindigo dicarboxylic acid and the hydroxy or amino form of R ¹ and R ² . X ¹ or X ² is -OC
In the case of O- or -NHCO-, it can be obtained by the condensation reaction of the hydroxy or amino thioindigo and the carboxylic acid, the acid anhydride or the acid chloride of R ¹ and R ² . X ¹ or
When X ² is —O—, it is a hydroxy form of thioindigo and R ¹
And a hydroxy form or halogen form of R ² can be obtained by a condensation reaction. When X ¹ or X ² is —CH ₂ O—, it can be obtained by a condensation reaction between the chloromethyl form of thioindigo and the hydroxy form of R ¹ and R ² . X ¹ or X ² is -CO- and -CH _2-
In the case of carboxylic acid chloride of thioindigo with R ¹ and R ²
-CO due to acylation by Friedel-Crafts reaction with
- give the body, -CH ₂ further by the reduction reaction - can be obtained body.

In addition, in the above-mentioned production method, a mixture of trans-cis form of the thioindigo skeleton of the fluorescent dye (in many cases, trans-form excess) can be obtained. Can be obtained as a body.

(Example) Example 1 Thioindigo-7,7'-dicarboxylic acid 180 mg (0.6 mmo
l) was refluxed with excess thionyl chloride for 3 hours. Excess thionyl chloride was distilled off under reduced pressure, and aminopyrene 250 mg (1.1
(5 mmol), 30 ml of benzene and 20 ml of pyridine were added, and the mixture was refluxed for 2 hours and then left for 5 days. Benzene and pyridine were distilled off under reduced pressure, and the residue was purified by silica gel column chromatography to obtain dipyrenylthioindigo-7,7'-
17 mg of a trans-cis mixture of dicarboxylic acid amide (abbreviated as DPTI) was obtained. Further, 64 mg of a by-product of a trans-cis mixture of thioindigo-7-carboxylic acid pyrenylamide-7'-carboxylic acid was obtained.

The properties of DPTI obtained above were as follows.

Dark red crystal mp 172-174 ℃ IR spectrum (cm ^-1 ) (KBr tablet) 1720,1660,1600,1530,128
0,1120,1030,840 UV (CHCl ₃ ) λmax (nm) 540,490,345 NMR (CDCl ₃ ) δppm 7.36 (brod, Ar-H) The DPTI mixture obtained above was dissolved in chloroform and 48
Irradiated with 0 nm light. Then the absorption band at λmax 490 nm decreases and 5
The 40 nm absorption band increased. It was confirmed that the cis-form in the DPTI mixture was converted to the trans-form by this light irradiation. The chloroform solution of this trans form was excited with 340 nm light and the fluorescence spectrum was measured. Monomeric emission of pyrene was observed at 380 nm and 410 nm.

The chloroform solution of trans-DPTI was irradiated with 550 nm light. The λmax 540 nm decreased and the λmax 490 nm absorption band increased. It was confirmed that cis-DPTI was obtained by this light irradiation. Add this cis-DPTI chloroform solution to
When excited by 0 nm light and the fluorescence spectrum was measured, a wide emission band of excimer emission was observed around 450 nm.

Example 2 64 mg of thioindigo-7-carboxylic acid pyrenylamide-7'-carboxylic acid, a by-product obtained in Example 1, was dissolved in 50 ml of anhydrous methylene chloride, 31 mg of N, N'-dicyclohexylcarbodiimide was added, and the mixture was stirred for 15 minutes. did. To this solution, 21 mg of p-nitroaniline was added and reacted at room temperature for 1 hour. This solution was added to 200 ml of cold water to separate the organic layer,
After washing with dilute hydrochloric acid and saturated aqueous sodium hydrogen carbonate, the extract was dried over sodium sulfate, and methylene chloride was distilled off under reduced pressure. The residue was purified by silica gel column chromatography and thioindi-7-
2 mg of a trans, cis mixture of carboxylic acid pyrenylamide-7'-carboxylic acid-p-nitrophenylamide was obtained.

The properties of the above product were as follows.

Dark red crystal IR spectrum (cm ^-1 ) (KBr tablets) 1720,1660,1540,1350,130
0,1100,850 UV (CHCl ₃ ) λmax (nm) 533,490,346,330 The above product was dissolved in chloroform and irradiated with 480 nm light. As a result, the absorption band at λmax 490 nm is reduced and λmax533
The nm absorption band increased. It was confirmed that the cis form in the mixture was converted to the trans form by this light irradiation. Next, when the chloroform solution of the trans form was irradiated with 540 nm light, the absorption band at λmax 533 nm decreased and the absorption band at λmax 490 nm increased. It was confirmed that a cis-isomer was obtained by this light irradiation.

When the chloroform solution of the above trans form was excited with 340 nm light and the fluorescence spectrum was measured, pyrene monomeric luminescence was observed at 387 nm and 407 nm.

Also, the chloroform solution of the cis form was similarly excited with 340 nm light and the fluorescence spectrum was measured to be 387 nm and 407 nm.
The pyrene monomeric luminescence was decreased, and the exciplex luminescence was increased near 440 nm.

Example 3 Thioindigo-7,7'-dicarboxylic acid 300 mg (1 mmol)
Was refluxed with excess thionyl chloride for 3 hours. Excess thionyl chloride was distilled off under reduced pressure, and 10 ml of hexamethylphosphoric triamide and 773 mg of 2-aminoanthracene (4m mo
l) was added and reacted overnight at room temperature. The reaction mixture is cold water 50m
In addition to 1, extracted with methylene chloride. Methylene chloride and hexamethylphosphoric triamide were distilled off under reduced pressure, and the residue was purified by silica gel column chromatography to obtain a trans-cis mixture of dianthranylthioindigo-7,7'-dicarboxylic acid amide (20 mg).

The properties of the above product were as follows.

Dark red crystal IR spectrum (cm ^-1 ) (KBr tablet) 1720,1660,1520,1300,845 UV (CHCl ₃ ) λmax (nm) 540,490,330 The above product (mixture of trans form and cis form) was dissolved in chloroform, Irradiated with 486 nm light. This gives λm
Absorber at ax490nm decreased and absorption band at λmax540nm increased. It was confirmed that the cis form in the mixture was converted to the trans form by this light irradiation. Next, when this chloroform solution of the trans form was irradiated with 550 nm light, λmax540n
The absorption band of m decreased and the absorption at λmax of 490 nm increased. It was confirmed that a cis-isomer was obtained by this light irradiation.

When the chloroform solution of the above trans form was excited with 330 nm light and the fluorescence spectrum was measured, anthracene monomeric luminescence was observed at 390 nm and 415 nm. Similarly, the chloroform solution of the cis isomer was excited with 330 nm light and the fluorescence spectrum was measured. As a result, excimer luminescence was observed near 470 nm.

(Effect of the invention) Since the fluorescent dye of the present invention has both a photochromic site and a site exhibiting fluorescence, the wavelength of fluorescence can be reversibly changed by controlling the structure of the photochromic site with light. This photochromic fluorescent dye can be used as an optical switch for changing the fluorescent wavelength and a variable color light display. Moreover, the optical memory using the photochromic region can be read nondestructively by using fluorescence.

Claims (2)

(57) [Claims] 1. A compound represented by the following general formula (I) or (II) having both a photochromic moiety composed of a thioindigo skeleton and two moieties having a fluorescent function, wherein the fluorescence wavelength is changed by photoisomerization of the photochromic moiety. A photochromic fluorescent dye that can be changed. However, in the above general formulas (I) and (II), -X ¹ -R ¹ and -X ² -R ² are respectively located at 7,7'-position, 4,4'-position or 4,7'-position, X ¹ and X ² may be the same or different, -COO-, -CONH-, -OCO-, -NHCO-, -O-,
Represents a group selected from --CH ₂ O--, --CO-- and --CH _2- , R
¹ and R ² each represent an organic group which emits fluorescence and may be the same or different. 2. R ¹ and R ^{2 of the} general formulas (I) and (II) each have the same or different substituents selected from methyl, halogen, nitro, amino, dimethylamino and dicyano. The photochromic fluorescent dye according to claim 1, which is a condensed-ring aromatic hydrocarbon group or a phenyl group having a substituent selected from nitro, amino, dimethylamino and dicyano.