JPH0543552A - Deuteratd compound and nonlinear optical material composed of the same - Google Patents

Abstract

PURPOSE:To obtain a deuterated compound having excellent performance as a nonlinear optical material with hardly any absorption by stretching vibration of carbon-hydrogen bonds and a small temperature rise by light absorption. CONSTITUTION:3,5-Dimethyl-1-(4-nitrophenyl)pyrazole (DMNP) having at least one, preferably >=4 deuterium atoms, especially the pyrazole ring has wholly deuterium atoms, e.g. compounds expressed by formulas I to III. The above- mentioned compound can be synthesized by using either of aromatic nucleophilic substitution reaction of a 3,5-dimethylpyrazole derivative with a 4- halogenonitrobenzene derivative or cyclizing reaction of a 4-nitrophenylhydrazine derivative or a 4-nitrobenzenediazonium salt derivative with an acetylacetone derivative into pyrazole. The resultant compound has the same nonlinear optical characteristics as those of DMNP, expressed by formula IV and having excellent performance as a nonlinear optical material and extremely useful as the nonlinear optical material.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a deuterium substitution product of a compound useful as a nonlinear optical material. It also relates to their use as non-linear optical materials.

[0002]

2. Description of the Related Art In recent years, a non-linear optical material-a material having a non-linearity between polarization and an electric field, which appears when a strong optical electric field such as laser light is applied-has attracted attention. Such materials are generally known as nonlinear optical materials and are described in detail in, for example, the following. "Nonlinear Optical Properties of Organic and Polymeric Materials"
C.S. Symposium Series 233 Edited by David Jay Williams (American Society of Chemistry 1983)
Annual) "" Nonlinear Optical Properties of Organic
and Polymeric Material "ACS SYMPOSIUM SERIES 23
3 Edited by David J. Williams (American Chemical Society,
1983) ”,“ Organic nonlinear optical materials ”Masao Kato
Supervised by Hachiro Nakanishi (CMC, published in 1985),
“Nonlinear Optical Properties of
"Organic Molecule's and Crystals", Volumes 1 and 2, edited by DS Smura and Jay Jiss (Academic Press, 1987), "" Nonlinear Opjtical Properties of Organic Mo
lecules and crystals "vol 1 and 2 DSChemla an
d. Edited by J. Zyss (Academic Press).

One of the applications of the nonlinear optical material is a second harmonic generation (SHG) based on the second-order nonlinear effect and a wavelength conversion device using a sum frequency and a difference frequency. So far, those which have been practically used are inorganic perovskites represented by lithium niobate. However, recently, it has become known that a π-electron conjugated organic compound having an electron-donating group and an electron-withdrawing group has various performances as a nonlinear optical material, which greatly exceeds the above-mentioned inorganic substances.

For the formation of higher performance nonlinear optical materials,
It is necessary to arrange compounds having a high nonlinear susceptibility in the molecular state so as not to generate inversion symmetry. It is known that a compound having a long π-electron conjugated chain is useful for the expression of a high non-linear susceptibility, which is one of them, and various compounds are described in the above-mentioned documents. Obviously, the maximum absorption wavelength becomes longer, and the transmittance of, for example, blue light is lowered, which hinders the generation of blue light as the second harmonic. This also occurs in the p-nitroaniline derivative, and the fact that the transmittance of the wavelength has a great influence on the efficiency of the second harmonic generation is explained by Alain Azema et al., Proceedings of SPII, Four
Volume 00, New Optical Materials (Alain
Azema et al., Proceedings of SPIE, Volume 400, NeW Op
(1983), page 186 (Fig. 4).

Therefore, the advent of a nonlinear optical material having a high transmittance for blue light has been desired. Conventionally, replacement of carbon atoms in the benzene nucleus of nitroaniline with nitrogen atoms has been studied, but satisfactory results have not always been obtained. JP-A-62-5 for the purpose of further improvement
9934, JP-A-63-23136, JP-A-63-
26638, JP-B-63-31768, JP-A-63.
-163827, JP-A-63-146025, JP-A-63-85526, JP-A-63-239427,
JP-A 1-100521 and JP-A 64-56425
Japanese Patent Application Laid-Open No. 1-102529 and Japanese Patent Application Laid-Open No. 1-10253
No. 0, JP-A 1-237625, JP-A 1-2077.
Many materials are disclosed in Japanese Patent Publication No. 24 and the like.

The applicant of the present invention has also disclosed a superior method in JP-A-62-210430 and JP-A-62-2.
It was disclosed in Japanese Patent No. 10432. In particular, JP-A-62-21
3,5-dimethyl-1- (4 disclosed in Japanese Patent No. 0432)
-Nitrophenyl) pyrazole is a very useful compound among the organic nonlinear optical materials known to date, showing the maximum value as a nonlinear optical constant having a phase matching non-diagonal tensor component. is there.

It is necessary to pay attention to the transparency to the fundamental wave input to the nonlinear optical material as well as the transparency to the second harmonic generated as described above. This has already been widely studied in the study of plastic optical fibers, and it has been clarified that in the case of an organic polymer material, absorption is observed at around 1 μm, which causes a propagation loss. The absorption around 1 μm is due to carbon-hydrogen bond, nitrogen-
It is considered to be due to the triple wave of stretching vibration of hydrogen bond and oxygen-hydrogen bond, and it is possible to reduce the absorption intensity by converting the hydrogen atom of these bonds into deuterium atoms. JP-A-54-65556, JP-A-57-
81204, JP-A-57-142601, JP-A-5
No. 8-149003, JP-A-58-154803, JP-A-61-20906, and JP-A-61-223805.

Also in the field of organic nonlinear optics,
Description of deuterium compounds is disclosed in JP-A-49-81051.
JP-A-63-21627, JP-A-63-1638
25, JP-A-2-149825, JP-A-2-247.
See 620. Further, DLAP obtained by partially deuterating LAP is also well known. However, the compounds described in these cannot necessarily be said to have sufficient performance, and a deuterium compound which is a compound having further excellent performance has been desired.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a deuterated compound having excellent performance as a nonlinear optical material.

[0010]

As a result of intensive studies, the inventors of the present invention have at least one deuterium atom,
It has been found that the object of the present invention can be achieved by 3,5-dimethyl-1- (4-nitrophenyl) pyrazole.
The number of deuterium atoms is preferably 4 or more, and particularly preferably the case where all pyrazole ring portions are deuterium atoms. Specific examples of the compound are shown below.

[0011]

[Chemical 1]

These compounds are obtained by nucleophilic aromatic substitution reaction of 3,5-dimethylpyrazole derivative to 4-halogenonitrobenzene derivative or to pyrazole by 4-nitrophenylhydrazine derivative or 4-nitrobenzenediazonium salt derivative and acetylacetone derivative. It can be synthesized using any of the ring closure reactions.

When the nucleophilic aromatic substitution reaction is used, heating is generally carried out using a solvent in the presence of a base catalyst. Examples of the base catalyst that can be used include inorganic bases composed of alkali metals or alkaline earth metals, and organic bases such as amines. Among these, inorganic bases are preferable, and among them, carbonates of alkali metals such as sodium carbonate, sodium hydrogen carbonate and potassium carbonate are preferable. The solvent can be selected from a range from polar solvents such as N, N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to nonpolar solvents such as benzene and hexane. Of these, aprotic solvents are preferable, and polar solvents such as DMF and DMSO are particularly preferable. The reaction temperature can range from 25 ° C to 180 ° C,
It is preferably 40 ° C to 150 ° C. Especially 60 ℃ ~ 13
The range of 0 ° C is preferred.

Regarding the ring-closing reaction using a hydrazine derivative or a diazonium salt derivative, "Heterocyclic Compounds Vol. 5", edited by RC Elderfield, Vol. 2
Chapters 45-161 (John Wiley & Sons-New York-195)
7 years) can be referred to. The ring-closing reaction is preferably carried out in the presence of an acid or base catalyst,
It is more preferable to use an acid. Inorganic acids such as hydrochloric acid and sulfuric acid are particularly preferable. The solvent can be selected from a range from polar solvents such as water, DMF and DMSO to non-polar solvents such as benzene and hexane. Of these, protic solvents such as water and alcohol are preferable, and water is particularly preferable. The reaction temperature can be in the range of 20 ° C to 200 ° C, preferably 50 ° C to 160 ° C. Especially 80 ℃ ~
The range of 140 ° C is preferred.

[0015]

EXAMPLES The present invention will be described in more detail based on examples. Example 1 Synthesis of Compound 1 1) Synthesis of acetylacetone (d ₇ ) Journal of the American Chemical Society
Society) Vol. 99, page 4572 (1977). Also, Vol. 75, page 5030, 8195.
It is also possible to use the method published in 3 years).

2) Synthesis of compound 1 5.72 g (53 mmol) of acetylacetone (d ₇ ).
And 4-nitrophenylhydrazine 7.96 g (52
80 ml of 12% deuterated hydrochloric acid was added to (mmol) and stirred at 60 ° C. for 4 hours. Activated carbon (3 g) was added while the mixture was hot, and the mixture was stirred for about 5 minutes and then suction-filtered to remove activated carbon and insoluble matter. The filtrate was ice-cooled, and a solution consisting of 14 g of sodium hydroxide and 53 ml of heavy water was gradually added thereto. The precipitated crystals were collected by filtration and washed with heavy water. After air drying, recrystallization was performed twice from i-propanol using activated carbon. 2.6 g (yield 22.3%) of the target compound was obtained. Melting point 102
The deuteration rate was examined by 103 ° C ¹ H-nmr. Methyl group is 3
90% in all of the 5th and 5th positions and 95% in the 4th position. Infrared absorption spectra of the compound 1 and the non-deuterated compound (DMNP) obtained here are shown in FIGS. 1 and 2. It can be seen that the absorption intensity of ν _CH is decreasing.

Compound 2 and compound 3 can be synthesized according to scheme 1.

[0018]

[Chemical 2]

Example 2 Synthesis of Compound 1 1) Synthesis of (II) (I) 50 g (0.51 mol) of anhydrous benzene 100 ml
52 g (0.51 mol) of acetic anhydride was added dropwise to the solution with stirring until the solvent gently boiled. After completion of dropping, the mixture was cooled to room temperature, the precipitated crystals were collected by filtration, washed with n-hexane and dried under reduced pressure to obtain a compound (II). Yield 64g (Yield 90%)

2) Synthesis of (III) A mixture of 150 ml of a 68% heavy aqueous nitric acid solution and 150 ml of a 98% heavy aqueous sulfuric acid solution was cooled to 0 ° C. in an ice bath, and 64 g (0.46 mol) of the compound (II) was stirred. The reaction mixture temperature is 5
It was added slowly so as not to exceed ℃. After the addition was completed, the mixture was stirred for 4 hours while maintaining the internal temperature at 0 to 5 ° C. After completion of the reaction, the reaction mixture was poured into 650 g of ice and the precipitated solid was collected by filtration and recrystallized with ethanol to obtain a compound (III). Yield 59g (70% yield)

3) Synthesis of (IV) Compound (III) (46 g, 0.25 mol) was added to sodium hydroxide (23 g, 0.58 mol) in water (40 ml) and ethanol (25).
The solution was added to the 0 ml solution little by little and then heated under reflux for 1 hour. After completion of the reaction, 300 ml of water was added dropwise with stirring to precipitate the desired product. After cooling in an ice bath, filtration and recrystallization with ethanol,
Compound (IV) was obtained. Yield 33g (Yield 92%)

4) Synthesis of (V) 33 g (0.23 mol) of compound (IV) was dissolved in 65 ml of 37% deuterated hydrochloric acid, and sodium nitrite was stirred under ice-cooling while maintaining the internal temperature at 0 to 5 ° C. A solution of 19.2 g (0.28 mol) of heavy water in 32 ml was added dropwise for diazotization. Next, 67 g (0.53 mol) of sodium sulfite and 12.8 g (0.32 mol) of sodium deuteride were dissolved in 320 ml of deuterated water, and the internal temperature was kept at 0 to 5 ° C. under ice cooling, while stirring, and diazonium. The salt solution was added dropwise. After completion of dropping, cool with ice 37
300 ml of% deuterium chloride was added. Then, the reaction mixture is heated to an internal temperature of 55.
Heat to ℃ and add 37% deuterated hydrochloric acid (64 ml) to the internal temperature of 70-80
The mixture was heated and stirred for 10 minutes while maintaining the temperature at ℃. The reaction mixture was filtered and neutralized with sodium carbonate to precipitate the desired product.
After collection by filtration, recrystallization was performed with ethanol to obtain a compound (V). Yield 24g (72% yield)

5) Synthesis of compound 2 5.3 g (53 mmol) of acetylacetone and 7.6 g (52 mmol) of compound (V) were added to 80 ml of 12% hydrochloric acid.
Was added, and 3 g of activated carbon was added while heating at 60 ° C. for 4 hours and stirred for about 5 minutes, followed by suction filtration to remove activated carbon and insoluble matter. The filtrate was ice-cooled, and a solution consisting of 14 g of sodium hydroxide and 53 ml of water was gradually added thereto. The precipitated crystals were collected by filtration and washed with water. After air-drying, recrystallization was performed twice from i-propanol using activated carbon to obtain compound 2. Yield 2.9 g (yield 25.0%) Melting point 102-103 ° C. FIG. 3 shows an infrared absorption spectrum of the compound 2 obtained here. It can be seen that the absorption of ν _CH is reduced compared to Fig. 2.

EXAMPLE 3 Synthesis of Compound 3 5.72 g (53 mmol) acetylacetone (d ₇ ).
And 12% to 7.6 g (52 mmol) of compound (V)
80 ml of deuterated hydrochloric acid was added, and the mixture was stirred at 60 ° C. for 4 hours. Activated carbon (3 g) was added while the mixture was hot, and the mixture was stirred for about 5 minutes and then suction-filtered to remove activated carbon and insoluble matters. The filtrate was ice-cooled, and a solution consisting of 14 g of sodium hydroxide and 53 ml of heavy water was gradually added thereto. The precipitated crystals were collected by filtration and washed with heavy water. After air-drying, 2 from i-propanol using activated carbon.
Compound 3 was obtained by repeating recrystallization. Yield 2.8 g (yield 23.2%) Melting point 102-103 [deg.] C. FIG. 4 shows an infrared absorption spectrum of the compound 3 obtained here. It can be seen that the absorption of ν _CH is reduced compared to Fig. 2.

Example 4 The measurement of the second harmonic generation was carried out by SK Kurt.
z), by TTPerry, Journal of Applied Physics (J.Appl.Phys.)
Vol. 39, page 3798 (published in 1968), according to the method described above, to the microcrystalline powder of the compound of the present invention. The measurement was performed by the apparatus shown in FIG. That is, the measurement was performed using pulsed YAG laser light (λ = 1.064 μm,
The beam diameter ≈ 1 mmφ, peak power ≈ 10 Mw / cm ² ) was used as the fundamental wave, and the intensity of the second harmonic was measured by the evaluation device shown in FIG. The measurement was performed by relative comparison with the intensity of the second harmonic of urea. When the strength was weak, visual observation was performed. In particular, in order to distinguish the light emission (mainly yellow and red light emission) due to the two-photon absorption of the fundamental wave and the second harmonic, a spectroscope was inserted and only the second harmonic was measured. As a result, all of Compounds 1, 2 and 3 generated about 16 times the second harmonic wave of urea as in DMNP. Therefore, it can be seen that the compound of the present invention is useful as a nonlinear optical material.

An X-ray crystal structure analysis of a single crystal of Compound 1 showed the same space group Pca2 as DMNP.
_{The value was 1} , and the lattice constants were almost equal. This is DMN
It has the same crystal structure as P,
Therefore, it has the same nonlinear optical characteristics as DMNP.

[0027]

[Table 1]

DMNP is an International Workshop on Crys.
talGrowth of Organic Materials) Proceedings P256 (1
It is an extremely excellent non-linear optical material as described in (989.12.7-9). The deuterated compound of the present invention having the same nonlinear optical property as this is extremely useful as a nonlinear optical material.

Example 5 A single crystal of Compound 1 and DMNP as a comparative example was prepared by the Bridgman-Stockburger method, and the single crystal was irradiated with 1064 nm light of an Nd-YAG laser. The temperature rise of the single crystal due to this was evaluated using a thermo camera. When 1 W is input, the temperature rise of Compound 1 is 0.7 ℃
However, it was 3.0 ° C. in DMNP. It was revealed that deuteration can reduce the temperature rise due to light absorption. If the temperature rises, there is a bad influence such as sublimation and decomposition. These can be prevented by deuteration and stable wavelength-converted waves can be taken out.

[0030]

According to the present invention, it is possible to obtain an excellent non-linear optical material that has less absorption due to stretching vibration of carbon-hydrogen bond and less temperature rise due to light absorption.

[Brief description of drawings]

FIG. 1 shows an infrared absorption spectrum of Compound 1.

FIG. 2 shows an infrared absorption spectrum of DMNP.

FIG. 3 shows an infrared absorption spectrum of compound 2.

FIG. 4 shows an infrared absorption spectrum of compound 3.

FIG. 5 shows a powder method SHG intensity measuring device.

[Explanation of symbols]

 1 powder sample 2 fundamental wave cut filter 3 spectroscope 4 photomultibryer 5 amplifier 6 light beam with wavelength 1.064 μm (fundamental wave) 7 light beam with wavelength 0.532 μm (second harmonic)

Claims (2)

[Claims] 1. A compound having at least one deuterium atom 3,
5-Dimethyl-1- (4-nitrophenyl) pyrazole. 2. A non-linear optical material comprising the compound of claim 1.