JPH11322685A - Aromatic oligoester, its production and use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel compound that has a good level of optical transparency and the secondary nonlinear optical property and is useful as an organic secondary nonlinear optical material. SOLUTION: This novel compound is represented by formula I (X is a dialkylamino, an alkylthio; Y is nitro or cyano; n is 1-3), typically the compound of formula II. The compound of formula I is prepared by reaction of an aromatic carboxylic halide of formula III (Hal is a halogen), for example, 4- dimethylaminobenzoyl chloride, with a p-substituted phenol, for example, 4- cyanophenol or the like in the presence of a hydrogen halide acceptor in an inert solvent such as acetone and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel aromatic oligoester having second-order nonlinear optical characteristics, a method for producing the same, and an organic second-order nonlinear optical material using the same.

[0002]

2. Description of the Related Art In the advanced information society in the future,
It is necessary to transmit large-capacity and precise information at high speed, high density and high efficiency. Light is expected to play an important role in this field by complementing electronic technology because it has properties such as parallel progression, spatial processing, large operability, and high density. Recently, an organic nonlinear optical material has been attracting attention as one of the materials necessary for utilizing the above.

[0005] The nonlinear effect of inorganic materials known so far is caused by lattice vibration absorption, whereas the nonlinear effect of organic materials is non-localized π.
This is due to the dipole moment generated when the electron system is distorted by the substituent and basically does not involve lattice vibration, so that a faster response is possible.

By the way, a second-order nonlinear optical material is required to have optical transparency and large nonlinear optical characteristics.
As such a second-order nonlinear optical material, Chained Chromophore has recently been used.
Attention has been paid to e) type organic nonlinear optical materials. This chained chromophore-type organic nonlinear optical material increases the μβ, one of the performance indices of the second-order nonlinear optical material, in proportion to the square of the number of units by linearly combining nonlinear active units. An organic material based on a concept. As one of such chained chromophore-type organic nonlinear optical materials, aromatic esters and aromatic ester oligomers are known. However,
Conventionally known aromatic esters and aromatic ester oligomers have good transparency, but their nonlinear optical properties have not always been sufficiently satisfactory.

[0005] The second-order nonlinear optical characteristic is a phenomenon that appears only when a substance lacks a center of symmetry. In the case of a polymer material, such a structure has the effect of applying an electric field to the nonlinear active species. Obtained by uniaxial orientation, the higher the degree of this orientation, the greater the performance. The degree of the orientation is greatly related to the magnitude of the dipole moment of the molecule. However, in the conventional aromatic esters and aromatic ester oligomers, the dipole moment is smaller than that of a general nonlinear active species. Since it is not so large, a good degree of orientation cannot be obtained, and as a result, the second-order nonlinear optical characteristics cannot be avoided.

[0006]

Under such circumstances, the present invention has good optical transparency,
An object of the present invention is to provide novel aromatic oligoesters having good second-order nonlinear optical characteristics.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to develop aromatic oligoesters having excellent second-order nonlinear optical characteristics. By introducing a specific substituent consisting of, the dipole moment can be increased while maintaining good optical transparency, and aromatic esters having excellent second-order nonlinear optical properties can be obtained. And completed the present invention based on this finding.

That is, the present invention provides a compound represented by the general formula

Embedded image (X in the formula is a dialkylamino group or an alkylthio group,
Y is a nitro or cyano group, and n is an integer of 1 to 3)
And a method for producing the same and a second-order nonlinear optical material comprising the aromatic oligoester.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic ester of the present invention has a structure represented by the above general formula (I),
This is a new compound not listed in the literature. In the general formula (I), the alkyl group in the dialkylcyano group and the alkylthio group represented by X includes an alkyl group having 1 to 4 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-type group. -Butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like. Among them, a methyl group is particularly preferable from the viewpoint of second-order nonlinear optical characteristics. On the other hand, Y is a nitro group or a cyano group.
The larger the n is, the more the second-order nonlinear optical characteristics are improved. However, when the n is 5 or more, the production becomes very complicated and impractical.

As the aromatic oligoesters represented by the general formula (I), 4-dimethylamino having the following chemical structure, in particular, has excellent optical transparency and excellent second-order nonlinear optical characteristics. 4-cyanophenyl benzoate (hereinafter abbreviated as ArES2-N / CN), 4-
(4'-dimethylaminophenylcarbonyloxy) benzoic acid 4-cyanophenyl ester (hereinafter ArES3-
N / CN), 4-dialkylaminobenzoic acid 4-nitrophenyl ester (hereinafter referred to as ArES2-N / N
O ₂ and abbreviated), abbreviated as 4-methylthio-benzoic acid 4-cyanophenyl ester (hereinafter ArES2-S / CN), 4- (4'- methylthiophenyl carbonyloxy) benzoic acid 4-cyano ester (hereinafter ArES3- S
/ CN).

The esters represented by the above general formula (I) are, for example,

Embedded image (Where Hal is a halogen atom, X, Y and n have the same meaning as described above)

Embedded image Wherein X, Hal and n have the same meanings as described above, and a general formula:

Embedded image (Y in the formula has the same meaning as described above)
Reacting a substituted phenol with a hydrogen halide scavenger, or

Embedded image Wherein n ′ is an integer of 1 or 2, and X, Y and Hal have the same meaning as described above.

Embedded image (Wherein X and Hal have the same meanings as described above), and p-substituted benzoic acid halide represented by the formula:

Embedded image (Y and n 'in the formula have the same meanings as described above), and can be produced by reacting with a p-hydroxybenzoic acid derivative in the presence of a hydrogen halide scavenger.

Ha in the compound represented by formula (II) or (IV) used as a starting compound for this reaction
Examples of l include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. As the hydrogen halide scavenger used in this reaction, tertiary amines such as trimethylamine, triethylamine and pyridine are preferable, but other organic bases and inorganic bases can also be used. These reactions are advantageously performed in an inert solvent such as acetone, methyl ethyl ketone, diethyl ether, ethyl acetate, tetrahydrofuran, dimethylformamide, diethyl sulfoxide, cyclohexane and the like.

On the other hand, when an alkali metal salt of a hydroxyl group, ie, phenolate, is used in place of the compound represented by (III) or (V) used as a raw material compound for this reaction, a hydrogen halide scavenger can be eliminated. The desired reaction can also be performed.

The starting compound (II) in these reactions
And (III) or (IV) and (V) are used in substantially stoichiometric amounts, but if desired, one of the starting compounds can be used in excess. In addition, these reactions are carried out at room temperature or under ice-cooling while the other starting compound is added little by little to a solvent containing the one starting compound, and the mixture is stirred. You can also. The reaction time is usually selected in the range of 1 to 30 hours. The reaction mixture thus obtained is washed with water according to a conventional method, the organic layer is separated, and the solvent is removed therefrom, whereby the target compound of the present invention is obtained as white or pale-colored crystals.

The p-type compound represented by the general formula (V)
The hydroxybenzoic acid derivative is, for example, represented by the general formula (II)
I) p-substituted phenols and general formulas

Embedded image (Wherein R is a lower alkyl group, Hal and n 'have the same meanings as above) in a solvent such as acetone, and in the presence of a hydrogen halide scavenger such as triethylamine. React under the general formula

Embedded image (Wherein R is a lower alkyl group, and Y and n 'have the same meanings as described above), and then hydrolyzed in a solvent such as acetone in the presence of a base catalyst. Can be manufactured by

The thus obtained general formula (I)
The compound of the present invention has good optical transparency,
It is a novel compound having excellent second-order nonlinear optical properties.
The second-order nonlinear optical characteristics of the polymethyl methacrylate thin film (aromatic ester content: 10% by weight) having a thickness of about 5000 ° in which the aromatic esters are dispersed have an optimum poling temperature in the range of 60 to 90 ° C. and also second-order nonlinear optical coefficient d ₃₃ value after poling at that temperature is ^{3 × 10 -9 ~4 × 10 -9} esu.

[0017]

Next, the present invention will be described in more detail with reference to examples.

Example 1 18 ml (254 mmol) of thionyl chloride was gradually added dropwise to 1.65 g (10.0 mmol) of 4-dimethylaminobenzoic acid, followed by stirring for 1 hour to react. After completion of the reaction, excess thionyl chloride was distilled off, and 20 ml of acetone was added to the residue to dissolve it, thereby preparing an acetone solution of 4-dimethylaminobenzoyl chloride.
Separately, 1.19 g (10.0 mmol) of 4-cyanophenol, 14.0 ml (101 mmol) of triethylamine and 30 ml of acetone were mixed, and this was mixed with the above-mentioned 4
Dropwise into a solution of -dimethylaminobenzoyl chloride in acetone under ice-cooling. After completion of the dropwise addition, the mixture was stirred overnight in an ice bath and reacted, and then the reaction mixture was poured into a 5% by weight aqueous K ₂ CO ₃ solution, and the formed precipitate was collected by filtration. Next, the obtained solid is recrystallized twice with an acetone / water mixed solvent, and then dried under reduced pressure at room temperature overnight to obtain a compound having the formula

Embedded image 1.17 g of ArES2-N / CN (yield 4)
3.9%) as a white solid, mp 152.0-153.5 ° C. ¹ H-N, which was carried out in the 400MHz of this thing
The result of the structural analysis by MR (CDCl ₃ ) is shown below. δ = 3.10 [s, 6H, (CH ₃ ) ₂ N-], 6.74
(D, J = 8.8 Hz, 2H, a aromatic proton of a),
7.35 (d, J = 8.8 Hz, 2H, c aromatic protons), 7.72 (d, J = 8.8 Hz, 2H, d aromatic protons), 8.04 (d, J = 8.8 Hz, 2
H, b aromatic protons).

Example 2 9.0 ml (127 mmol) of thionyl chloride was gradually added dropwise to 0.83 g (5.00 mmol) of 4-dimethylaminobenzoic acid, and the mixture was stirred for 1 hour to react. After completion of the reaction, excess thionyl chloride was distilled off, and 40 ml of acetone and 3.0 ml of triethylamine were added to the residue.
An acetone solution was prepared. Separately, 1.20 g (5.00 mmol) of 4-hydroxybenzoic acid 4-cyanophenyl ester and 4.0 ml of triethylamine (total amount 50.0%)
(Mmol) and 20 ml of acetone was prepared and added dropwise to the acetone solution under ice-cooling. After the completion of the dropwise addition, the mixture was stirred overnight in an ice bath, and then the reaction mixture was poured into a 5% by weight aqueous NaHCO ₃ solution. The precipitate is separated by filtration and recrystallized twice with an acetone / water mixed solvent.
It dried under reduced pressure at room temperature overnight. Thus, the expression

Embedded image 0.81 g of ArES3-N / CN represented by
1.9%) as a white solid having a melting point of 190 ° C. or higher.
The results of a structural analysis of this product by ¹ H-NMR (CDCl ₃ ) are shown below. δ = 3.10 [s, 6H, (CH ₃ ) ₂ N-], 6.71
(D, J = 8.8 Hz, 2H, a aromatic proton of a),
7.38 (aromatic protons of m, 4H, c and e),
7.76 (d, J = 8.8 Hz, 2H, f aromatic protons), 8.06 (d, J = 8.8 Hz, 2H, b aromatic protons), 8.25 (d, J = 8.8 Hz, 2
H, d aromatic protons).

Example 3 Instead of 4-cyanophenol in Example 1, 4-cyanophenol was used.
Using 1.39 g (10.0 mmol) of nitrophenol, the aqueous solution to which the reaction mixture was poured was 5% by weight of NaHCO 3.
_{3 The same} procedure as in Example 1 was carried out except that the aqueous solution was replaced with the aqueous solution.

Embedded image ArES2-N / NO ₂ 0.4 as a yellow solid represented by
2 g (14.7% yield) was obtained. ¹ H-NM of this one
The result of the structural analysis using R (CDCl ₃ ) is shown below. δ = 3.10 [s, 6H, (CH ₃ ) ₂ N-], 6.74
(D, J = 8.8 Hz, 2H, a aromatic proton of a),
7.40 (d, J = 8.8 Hz, 2H, c aromatic protons), 8.04 (d, J = 8.8 Hz, 2H, b aromatic protons), 8.30 (d, J = 8.8 Hz, 2
H, d aromatic protons).

Example 4 5.00 g (42.0 mmol) of 4-cyanophenol
, Acetone 20ml and triethylamine 5.8ml
(42.0 mmol) and 7.84 g (42.0 mmol) of 4-methylthiobenzoyl chloride in 20 m of acetone.
Add the solution dissolved in l and stir under ice-cooling.
Allowed to react overnight. After completion of the reaction, the product was extracted from the reaction mixture with methylene chloride, washed with water six times, the solvent was distilled off, and the residue was recrystallized twice with acetone / water. The resulting residue was dried under reduced pressure at room temperature overnight to obtain a compound of the formula

Embedded image 8.23 g of ArES2-S / CN represented by
2.8%) was obtained as a white solid. ¹ H of this thing
The result of structural analysis by -NMR (CDCl ₃ ) is shown below. δ = 2.55 (proton of s, 3H, a), 7.32
(D, J = 8.4 Hz, 2H, b aromatic protons),
7.36 (d, J = 8.4 Hz, aromatic proton of 2H, d), 7.74 (d, J = 8.8 Hz, aromatic proton of 2H, e), 8.07 (d, J = 8.4 Hz, 2
H, c aromatic protons).

Example 5 4-Hydroxybenzoic acid 4-cyanophenyl ester (1.00 g, 4.18 mmol) was mixed with acetone (20 m).
1, triethylamine 0.6 ml (4.33 mmol)
And 0.78 g (4.18 mmol) of 4-methylthiobenzoyl chloride dissolved in 10 ml of acetone were added,
The reaction was carried out by stirring overnight under ice cooling. After completion of the reaction, the reaction mixture was extracted with methylene chloride, the extract was washed four times with water, and the solvent was distilled off. The obtained residue was recrystallized twice using acetone / water, and then dried under reduced pressure at room temperature overnight to obtain a compound of the formula

Embedded image 1.48 g of ArES3-S / CN represented by (yield 9
0.9%) as a white solid. ¹ H-N of this thing
The result of the structural analysis by MR (CDCl ₃ ) is shown below. δ = 2.59 (proton of s, 3H, a), 7.33
(D, J = 8.0 Hz, 2H, b aromatic proton),
7.39 (m, 4H, d and f aromatic protons),
7.76 (d, J = 8.4 Hz, 2H, g aromatic protons), 8.10 (d, J = 8.0 Hz, 2H, c aromatic protons), 8.27 (d, J = 9.2 Hz, 2
H, e aromatic protons).

Reference Example 1 ArES2-N / CN, ArES3 obtained in Examples 1 to 5
-N / CN, ArES2-N / NO 2, ArES2-S
/ CN and ArES3-S / CN were each dissolved in acetonitrile to prepare a solution having a concentration of 10 ⁻⁵ mol / l. The UV absorption spectra of these solutions were measured, and the maximum absorption wavelength [λ _max ] and the cut-off wavelength [λ _CO ] were determined. Table 1 shows the results.

[0024]

[Table 1]

Reference Example 2 ArES2-N / CN and ArES3 obtained in Examples 1 to 5
-N / CN, ArES2-N / NO 2, ArES2-S
/ CN and ArES3-S / CN respectively.
02 g was mixed with 0.18 g of polymethyl methacrylate and 5 ml of chloroform to prepare two kinds of polymer solutions. Using this polymer solution, a thin film having a thickness of about 5000 mm was formed on a glass substrate having a thickness of 1.0 mm by a spin coating method (500 rpm, 30 seconds). When the ultraviolet absorption spectrum of this thin film was measured and compared with the ultraviolet absorption spectrum of the solution of Reference Example 1, good agreement was confirmed for each compound. From this, it is found that each compound is molecularly dispersed in the thin film. Next, these thin films were subjected to a corona poling treatment (5 kV / cm) at various poling temperatures to determine the optimum poling temperature. After subjected to poling treatment at the optimum temperature, the second harmonic generation (SHG) was measured by the manufacturer fringe method, to calculate the second-order nonlinear optical coefficient d ₃₃ value according to a conventional method. Table 2 shows the results.

[0026]

[Table 2]

[0027]

The present invention provides a novel aromatic ester oligomer having good second-order nonlinear optical characteristics and optical transparency.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G02F 1/35 504 G02F 1/35 504 (72) Inventor Takashi Fukuda 4-802, 205, Namiki 4-chome, Tsukuba-shi, Ibaraki Prefecture (72) Invention Person Tatsumi Kimura 2641 Yamazaki, Noda-shi, Chiba Pref., Tokyo University of Science (72) Inventor Masao Kato 2641 Yamazaki, Noda-shi, Chiba Pref. 1-1 Inside the Institute of Reaction Chemistry, Tohoku University (72) Hachiro Nakanishi 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi Prefecture Inside the Institute of Reaction Chemistry, Tohoku University

Claims (4)

[Claims] 1. A compound of the general formula (X in the formula is a dialkylamino group or an alkylthio group,
Y is a nitro or cyano group, and n is an integer of 1 to 3)
Aromatic oligoesters represented by the formula: 2. A compound of the general formula (X in the formula is a dialkylamino group or an alkylthio group,
Hal is a halogen atom, and n is an integer of 1 to 3), and an aromatic carboxylic acid halide represented by the following general formula: Wherein Y is a nitro group or a cyano group, and reacted with a p-substituted phenol in the presence of a hydrogen halide scavenger. (Wherein X, Y and n in the formula have the same meanings as described above). 3. A compound of the general formula (X in the formula is a dialkylamino group or an alkylthio group,
Hal is a halogen atom), and an aromatic carboxylic acid halide represented by the general formula: Wherein Y is a nitro group or a cyano group, and n 'is an integer of 1 or 2, and reacted with a p-hydroxybenzoic acid ester in the presence of a hydrogen halide scavenger. The general formula (Wherein X, Y and n ′ in the formula have the same meanings as described above). 4. A compound of the general formula (X in the formula is a dialkylamino group or an alkylthio group,
Y is a nitro or cyano group, and n is an integer of 1 to 3)
A second-order nonlinear optical material comprising an aromatic oligoester represented by the formula: