JP2553953B2 - Novel 1-aryl substituted azole and nonlinear optical material containing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel compound useful as a nonlinear optical material and a nonlinear optical material containing the same.

2. Description of the Related Art In recent years, attention has been focused on non-linear optical materials—materials having nonlinearity between polarization and electric field, which appear when a strong optical electric field such as laser light is applied.

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," ACS Symposium Series 233, edited by David J. Williams (American Chemical Society, 1983), "Nonlinear Optical Properties of Organic an
d Polymeric Material "ACS SYMPOSIUM SERIES 233 Dav
id J. Williams (American Chemical Society, 1983), "Organic Nonlinear Optical Materials" Masao Kato, Hachiro Nakanishi (CMC, 1985, "Nonlinear Optical Properties of Organic.""Molecules and Crystals" Volumes 1 and 2, edited by DS, Shmura and Jay Jess (Academic Press, 1987) "" Nonlinear Op
tical Properties of Organic Molecules and Crystal
s "vol 1 and 2 DS Chemla and J. Zyss (Academic P
ress company).

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.

In order to form a higher-performance nonlinear optical material, it is necessary to arrange compounds having a high nonlinear susceptibility in a molecular state so as not to cause 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 blue light decreases, for example, 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 SPI, Volume 400, New Optical Materials (Alain Azma et al.,
Proceedings of SPIE, Volume 400, Now Optieal Material
s), (1983), page 186, FIG.

Therefore, the emergence of a nonlinear optical material having a high transmittance for blue light is desired. Conventionally, replacement of carbon atoms in the benzene nucleus of nitroaniline with nitrogen atoms has been studied, but satisfactory results have not necessarily been obtained.

Therefore, as a nonlinear optical material having a high blue light transmittance, JP-A-62-59934, JP-A-63-23136, and JP-A-63-26663 are used.
No. 8, JP-B-63-31768, JP-A-63-163827, JP-A-SHO
63-146025, JP-A-63-85526, JP-A-63-239427
JP-A-1-100521, JP-A-64-56425, JP-A-1-102529, JP-A-1-102530, and JP-A-1-237625.
Many materials are disclosed in Japanese Patent Application Laid-Open No. 1-207724 and the like.

In addition, the present applicant has disclosed in Japanese Patent Application
-210430 and JP-A-62-210432, and JP-A-2
-42423 gazette.

In particular, 3,5-dimethyl-1- (4-nitrophenyl) pyrazole (DMN) disclosed in JP-A-62-210432 is disclosed.
P) is evaluated to be an extremely excellent compound (for example, Takashi Kondo et al., Optronics 98 Vol. 2, No. 132, p. 199).
0 years).

By the way, one of the usefulness of the blue light laser is to improve the recording density of the optical disk. In this case, the shorter the wavelength of the laser light, the better. Therefore, it is desirable that the material used for the SHG element also has a shorter absorption wavelength. From this point of view, further shortening of the absorption wavelength is desired in DMNP. When considering use in the crystalline state, the absorption tail measured in the solution state has a substantial effect, and therefore, a slight shortening of the absorption tail in the solution state can be a great advantage. .

Theoretical prediction of the maximum value of the absorption wavelength can be easily performed by using, for example, the molecular orbital method. However, it is extremely difficult to predict the extent of the absorption band, that is, the tail of absorption. Furthermore, it is also extremely difficult to predict the molecular arrangement in the crystal, and therefore it is extremely difficult to predict the resulting molecular structure of the SHG-active crystal.

Therefore, it is not easy to develop a compound having high blue light transmittance and giving an SHG-active crystal.

(Problems to be Solved by the Invention) Therefore, a first object of the present invention is to provide a useful chemical substance.

The second object of the present invention is to have excellent blue light transmittance and SHG.
It is to provide compounds which give crystals which are active.

The third object is to provide a nonlinear optical material containing the compound.

(Means for Solving the Problem) As a result of intensive studies, the present inventors have found that the compound represented by the following general formula can achieve the object of the present invention.

In the formula, X represents a methyl group or a hydrogen atom, when X = CH ₃ , A = N, Y = CH ₃ , B = N, and when X = H, A = C-COOC ₂ H ₅ , Y = H, is B = C-CH _3.

The compounds of formula (I) and formula (II) can be generally synthesized by the following method.

X: halogen Z ¹ : atomic group necessary for forming a benzene ring or a pyridine ring Z ² : atomic group necessary for forming a triazole ring or a pyrazole ring As the base used, pyridine, triethylamine,
It may be any of organic bases such as 1,8-diazabicyclo [5,4,0] -7-undecene, inorganic bases such as potassium carbonate, sodium hydrogen carbonate, potassium t-butoxide, sodium hydride and sodium hydroxide. . Examples of the solvent include hydrocarbons such as n-hexane, ethers such as tetrahydrofuran, 1,2-dimethoxyethane, amides such as N, N-dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, and sulfolane. Sulfur compounds, nitriles such as acetonitrile, esters such as ethyl acetate and the like are used. Among them, amide,
A sulfur-containing compound and nitrile are preferable. The reaction temperature is −
10 ° C to 150 ° C, preferably 20 ° C to 100 ° C is desirable.

When the compound of the present invention is used as a non-linear optical material, it can be used in various forms such as a powder form, a single crystal form, and the inclusion of molecules in a host lattice (polymer, inclusion compound, solid solution, liquid crystal). It can be used. Further, the application as a nonlinear optical material is not limited to the wavelength conversion element,
Any element can be used as long as it utilizes a nonlinear optical effect. As a specific example of an element in which the nonlinear optical material of the present invention can be used, in addition to the wavelength conversion element, an optical bistable element (optical storage element, optical pulse waveform control element, optical limiter, differential amplification element, optical transistor, A / D Conversion element,
Optical logic elements, optical multivibrators, optical flip-flop circuits, etc.), optical modulators, phase conjugate optical elements, etc.

Examples of the laser light source used as the fundamental wave include those shown in Table 1. The wavelength of the fundamental wave is not limited except for the influence of the absorption of the above-mentioned material. This means that laser and optronics (La
Ser & Optronics), p. 59 (November 1987).

(Example) Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1 Synthesis of Compound of Formula (I) 3,5-Dimethyl-1H-1,2,4-triazole 48.5 g (0.5
Mol), 2-chloro-5-nitropyridine 79.3 g (0.5 mol) and potassium carbonate 69.0 g (0.5 mol) were weighed into a 500 ml three-necked flask equipped with a stirrer and a thermometer, and further 250 ml.
Dimethylsulfoxide (DMSO) was added. After continuing stirring at 50 ° C for 5 hours, the mixture was allowed to cool to room temperature and poured into 500 ml of ice water. The precipitated crystals were collected by filtration and washed with water. The crystals were recrystallized twice with acetone while being decolorized with activated carbon to obtain a compound of formula (I). Yield 48g (Yield 4
3.8%) Melting point: 147 ° C ¹ H-nmr (δppm): 2.433 (3Hs), 2.914 (3Hs), 8.069
(1Hd), 8.617 (1Hdd), 9.316 (1Hd) Example 2 Synthesis of compound of formula (II) Ethylpyrazole-4-carboxylate 1.40 g (10
Mmol), 2-fluoro-5-nitrotoluene 1.55 g
(10 mmol) and 1.38 g (10 mmol) of potassium carbonate were weighed into a 25 μm three-necked flask equipped with a stirrer and a thermometer, and 10 ml of DMSO was further added. After continuing stirring at 50 ° C. for 5 hours, the mixture was allowed to cool to room temperature and poured into 50 ml of ice water. The precipitated crystals were collected by filtration and washed with water. The crystals were recrystallized twice with ethanol while being decolorized with activated carbon to obtain a compound of formula (II).

Yield: 1.05 g (yield 38.1%) Melting point: 105 ° C ¹ H-nmr (δppm): 1.385 (3Ht), 2.453 (3Hs), 4.359
(2Hq), 7.556 (1Hd), 8.161 to 8.256 (4H) Example 3 In order to evaluate blue light transmittance, an ultraviolet-visible absorption spectrum of an ethanol solution was measured. Table 2 shows the results.

All the comparative compounds are disclosed in JP-A-62-210432.

In the table, ▲ λ ⁹⁵ _c ▼ and ▲ λ ⁹⁹ _c ▼ are each 4 × 10 ^-4 mole
It is a wavelength showing a transmittance of 95% and 99% in an ethanol solution of /.

The compound of the present invention is expected to be excellent in blue light transmissivity when it is used as a crystal because it has less absorption tailing.

Example 4 The measurement of the second harmonic generation is performed by SKKu
rtz), TTPerry, Journal of Applied Physics (J.Appl.Phy)
s.) 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 is based on pulsed YAG laser light (λ = 1.064
μm, beam diameter ≈ 1 mmφ, peak power ≈ 10 Mw / cm ² ) was used as the fundamental wave, and the second harmonic intensity 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 between the emission due to two-photon absorption of the fundamental wave (mainly yellow and red emission) and the second harmonic, a spectroscope was inserted and only the second harmonic was measured. Further, the measurement by the powder method is mainly for judging the presence or absence of non-linearity of the substance, and the intensity ratio is a reference value of the magnitude of non-linearity.

 The results are shown in Table 3.

From the above results, it can be seen that SHG activity is lost due to a slight difference in molecular structure, and the compound of the present invention is useful as a nonlinear optical material.

(Effects of the Invention) From the above examples, it is understood that the novel compound of the present invention can be a useful nonlinear optical material having excellent blue light transmittance.

[Brief description of drawings]

FIG. 1 shows the measuring apparatus of the powder method, and the numbers in the figure are shown below. 1: Powder sample, 2: Fundamental wave cut filter 3: Spectroscope, 4: Photomul, 5: Amplifier (11): Wavelength 1.064 μm, (12): 0.532 μm

Claims (4)

(57) [Claims] 1. A compound represented by the following general formula: In the formula, X represents a methyl group or a hydrogen atom, when X = CH ₃ , A = N, Y = CH ₃ , B = N, and when X = H, A = C-COOC ₂ H ₅ , Y = H, is B = C-CH _3. 2. A compound represented by formula (I):
The compound according to the item. 3. A compound represented by the formula (II):
Compound of item 4. A nonlinear optical material containing the compound according to claim 2 or 3.