JP3084964B2 - Method for producing cyclobutenedione derivative crystals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cyclobutenedione crystal having excellent pyroelectric and piezoelectric properties, a function of converting a fundamental wave into a second harmonic having a half wavelength, and a laser oscillation function. It relates to a method of manufacturing.

[0002]

2. Description of the Related Art Conventionally, attempts have been made to convert laser light into short wavelength light. As an optical wavelength conversion element that performs such optical wavelength conversion, specifically, for example, “Basics of Optoelectronics” The one using a bulk crystal as shown in Yariv, Kunio Tada, translated by Takeshi Kamiya (Maruzen Co., Ltd.), pp. 200-204, is well known. As a crystal constituting the light wavelength conversion element, an inorganic nonlinear optical crystal such as potassium phosphate titanate (KTP = KTiOPO ₄ ) or lithium niobate (LN = LiNbO ₃ ) is conventionally known. By the way, since the conversion efficiency has a higher value in proportion to the square of the nonlinear optical constant of the material, organic nonlinear optical materials having larger nonlinearity and a higher response speed than inorganic nonlinear optical materials have been actively studied in recent years. Has been made. Since an organic molecule takes a polarized structure by itself, it can be used as a nonlinear optical crystal by growing a non-centrosymmetric crystal.

The present inventors have already reported that a cyclobutenedione derivative molecule has a high nonlinear effect by a powder method (Japanese Patent Application Laid-Open Nos. 2-333172 and 2-333).
173, 2-333174 and 2-333175). As a result of X-ray analysis, the following structural formula (I)

Embedded image ( Wherein , R represents a methyl group and * represents an asymmetric carbon atom). A cyclobutenedione crystal represented by the formula: triclinic system, space group P1, and a crystal in which molecules are completely one-dimensionally arranged. (LS Pu, ln “Mat”
erials for Nonlinear Opti
cs ": ChemicalPerspectives;
S. Marder, J.A. Sohn and G.S. S
tucky Rd. ACS Symposium
Series No. 455; American C
chemical Society: Washingt
on DC, p331-342 (1991);
S. Pu, J. et al. Chem. Comm. , 429 (19
91)).

[0004]

The organic single crystal reported so far has a higher nonlinear optical constant (d constant) than the inorganic single crystal as described above, but has a value of 100 pm / V.
Single crystals having the above nonlinear optical constants are not known. Since the cyclobutenedione derivative represented by the general formula (I) also has a high nonlinear effect, a high exchange efficiency can be expected by using it as an optical wavelength conversion element. However, conventionally, a method for producing a large crystal of a cyclobutenedione derivative has not been known, and therefore, the cyclobutenedione derivative cannot be used as a light wavelength conversion element. Accordingly, an object of the present invention is to provide a method for producing a single crystal of a cyclobutenedione derivative having a size usable as a light wavelength conversion element.

[0005]

Means for Solving the Problems The present inventors have found that the above object can be achieved by performing crystal growth of cyclobutenedione derivatives under specific conditions using a polar solvent. In the method for producing a cyclobutenedione derivative crystal of the present invention, the cyclobutenedione derivative represented by the above structural formula (I) is dissolved in a polar solvent, and the temperature fluctuation range is ± 1 within an atmosphere temperature of 10 to 40 ° C. The method is characterized in that the solvent is evaporated at an evaporation rate of 0.1 to 100 mm ³ per minute while keeping the temperature within ° C.

In the present invention, as the polar solvent, those which dissolve the cyclobutenedione derivative represented by the above structural formula (I) at a liquid temperature of 10 to 40 ° C. can be used. , Ethanol and the like, and methanol is particularly preferred.

In the present invention, the crystal is grown at an evaporation rate of 0.1 to 100 mm ³ per minute while keeping the temperature fluctuation range within ± 1 ° C. in an atmosphere temperature range of 10 to 40 ° C. is necessary. In particular, the ambient temperature is 10
In the range of 25 ° C., it is preferable to perform the evaporation at a rate of ³ to 10 mm ³ per minute while keeping the temperature fluctuation range within ± 0.5 ° C. When the ambient temperature drops below 10 ° C,
If the solubility is too low, it takes too much time to form a crystal, and if it is higher than 40 ° C., many nests are formed or polycrystallization occurs, and the quality of the crystal deteriorates. If the fluctuation range of the temperature exceeds ± 1 ° C., many nuclei are generated and the crystal does not become large. Further, the rate of evaporation Below the 0.1 mm ^3, the higher than crystals produced takes time only ,, 100 mm ^3, nucleus crystals of greatly occurs to a desired size can not be obtained.

[0008]

The single crystal of the cyclobutenedione derivative produced under the above conditions usually has a size of 1 to 30 mm ³ , and its d constant (d ₃₃ ) is theoretically about 45
It has a value of 4 pm / V and has a high nonlinear optical constant. Further, X-ray analysis confirmed that this single crystal was a triclinic crystal having a space group of P1 and molecules in parallel.

This single crystal can perform type I and type II angular phase matching based on the refractive index, and when this single crystal is cut in the phase matching direction, an optical wavelength conversion element can be assembled in a bulk state. . Therefore, the single crystal is a space group with 3 monoclinic system P1, since molecules are parallel aligned crystals, it can be used as a waveguide, an optical wavelength conversion element utilizing thoroughly d ₃₃ Shows high conversion efficiency.

[0010]

【Example】

Example 1 FIG. 1 shows the solubility curves of the cyclobutenedione derivative (DAD) represented by the structural formula (I) in methanol, ethanol, and acetone. As is apparent from FIG.
Since AD is well dissolved in methanol, methanol was used as a solvent. Next, the solubility curve and the super solubility curve are shown in FIG. As is clear from this figure, since the solubility curve 1 and the supersolubility curve 2 become almost equal at 22 ° C., the solvent evaporation method was attempted at 22 ° C. ± 0.1 ° C at 22 ° C
The temperature was kept within 1 ° C. in a room kept within, the evaporation rate of the solvent was set to a predetermined value, and seed crystals were grown in an Erlenmeyer flask. As a result, when the evaporation rate was ^{3 to} 5 mm ³ / min, crystals having a good shape of 0.5 to 1 mm square could be obtained. Thereafter, a saturated methanol solution of DAD was placed in an Erlenmeyer flask, and the Erlenmeyer flask was placed in an enclosure where the temperature was kept constant. Then, the seed crystal obtained as described above is put into this Erlenmeyer flask, and at a temperature of 22 ° C., the temperature fluctuation range is kept within ± 0.1 ° C. and 3 to 5 mm
They were grown at an evaporation rate of ³ / min. As a result, a DAD crystal having a maximum size of 1 × 4 × 4 mm ³ was obtained. The supramolecular polarizability (β) of DAD measured by the solvatochromic method using dioxane as a solvent is 171 × 10
^-30 esu, it is estimated that the d constant of DAD is a considerably high value.

[0011]

According to the method of the present invention, a single crystal of a cyclobutenedione derivative having a large size can be obtained, and the obtained single crystal can be used for various applications as a light wavelength conversion element. For example, it can be used as an element utilizing a wavelength conversion technique in an optical scanning recording device that performs precision scanning, an optical scanning reading device, and the like. Also,
It has excellent pyroelectricity and piezoelectricity, and can be used, for example, as a piezoelectric element.

[Brief description of the drawings]

FIG. 1. Solubility curves of cyclobutenedione derivatives in various solvents.

FIG. 2 shows a solubility curve and a super solubility curve of a cyclobutenedione derivative in methanol.

[Explanation of symbols]

 1 ... Solubility curve, 2 ... Super solubility curve.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-333172 (JP, A) JP-A-2-333173 (JP, A) JP-A-2-333174 (JP, A) JP-A-2-333 333175 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 225/22 C07C 221/00 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. The following structural formula (I): ( Wherein , R represents a methyl group, and * represents an asymmetric carbon atom). A cyclobutenedione derivative represented by the following formula: A method for producing a cyclobutenedione derivative crystal, comprising evaporating a solvent at an evaporation rate of 0.1 to 100 mm ³ per minute while maintaining the temperature within ± 1 ° C.