JPH04202166A - Cyclobutenedione derivative and its production - Google Patents

Abstract

NEW MATERIAL:Compounds of formula I [R1 and R2 are alkyl; R3 is formulae IV-VII (C* is asymmetric C)]. EXAMPLE:1-(3',4'-Dimethoxyphenyl)-2-(1'-hydroxymethyl-2'-phenylethylam ino)- cyclobutene-3,4-dione. USE:A non-linear optical material showing high non-linear characteristics and excellent in heat resistance, light resistance, shelf life and workability. PREPARATION:A cyclobutenedione derivative of formula II (X is Cl, Br, methoxy or ethoxy) is allowed to react with an amino acid derivative of formula III to obtain the objective compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel cyclobutenedione derivative useful as a nonlinear optical material and a method for producing the same.

(Prior Art) Nonlinear optical elements play an important role in the fields of optical communication and optical information processing. Nonlinear optical materials used in nonlinear optical elements are capable of light mixing that generates the sum and difference frequencies of two types of incident light with different frequencies, optical parametrics that generate two types of light with different frequencies, and the refractive index of the optical medium. Substances that play an extremely important role in optical signal processing, such as the Pockels effect or Kerr effect that changes the energy, the conversion of incident light into second harmonics (SHG) or third harmonics (THG), and optical bistability. It is. Conventionally, inorganic materials have been mainly used as such nonlinear optical materials.

Regarding inorganic nonlinear optical materials, KD:F) (KH2PO4) and lithium niobate (
Although crystals of inorganic compounds such as LiNb03) are known, they are not sufficient to fully satisfy the requirements.

On the other hand, organic nonlinear optical materials have recently attracted attention as new materials for optical elements in the field of optoelectronics, and research on them has become more active year by year. In particular, many studies have been conducted on organic compounds having a π-electron conjugated system to search for materials because of their high performance as a single molecule and high-speed response.

In general, it is known that crystals of organic nonlinear optical materials have a SHG coefficient 10 to 100 times larger than crystals of inorganic nonlinear optical materials, a photoresponse speed of about 1000 times, and a threshold for photodamage that is also larger. It is being

Recently discovered organic nonlinear optical materials include 2
-Methyl-4-nitroaniline, m-nitroaniline,
N-(4-nitrophenyl)-L-prolinol, 2-
acetylamino-4-nitrosilbene, N-dimethylaniline, 4-dimethylamino-4'-nitrostilbene,
Examples include organic compounds such as 4'-dimethylamino-N-methyl-4-stilbazolium methyl sulfate and 4'-methylbenzylidene-4-nitroaniline.

The optical nonlinearity of organic compounds with these π-electron conjugated systems is related to laser light as an electromagnetic wave and organic compounds.

This is caused by interaction with electrons, and this interaction can be further increased by introducing an electron-withdrawing or electron-donating substituent into the π-electron conjugated system.

However, in such organic compounds, the dipole moment generally increases, and the dipole-dipole interaction during crystallization becomes stronger, resulting in a central symmetry structure in which the dipoles of two molecules cancel each other out. It becomes easier to form crystals. There is a problem in that the second-order nonlinear optical effect, which is important in practical applications, does not occur in such centrosymmetric crystals. Therefore, in order to break the central symmetry, which is a problem in expressing optical nonlinearity in the crystal state, substituents with hydrogen bonding ability and optically active substituents with asymmetric carbon atoms are added to π-electron conjugated systems. An idea has been devised to introduce it into organic compounds that have it at the time of molecular design. The present inventor introduced an optically active substituent having such an asymmetric carbon atom into a π-electron conjugated system,
Although a specific example of a material exhibiting a thicker nonlinear effect than conventional materials has been disclosed in Japanese Patent Application No. 1-248108, an even greater improvement in the nonlinear effect is desired.

(Problems to be Solved by the Invention) Generally, the characteristics required for a material for a nonlinear optical element are the magnitude of optical nonlinearity, light transmittance, laser damage resistance, crystallinity, phase matching, and processability. , mechanical strength, hygroscopicity and hardness.

It has been extremely difficult to select from conventionally known materials for organic nonlinear optical elements that satisfy the above-mentioned practically required characteristics.

The present invention has been made in view of the above-mentioned actual situation in the prior art.

Therefore, an object of the present invention is to improve the problems with the conventionally known materials for nonlinear optical elements, to provide a practical material that has larger nonlinear optical effects, and has improved storage stability, processability, and transparency. The object of the present invention is to provide a material for an organic nonlinear optical element.

(Means for Solving the Problems) The present inventors have proposed that by introducing an appropriate substituent into the molecule, even if the molecular dipole moment is large and the compound system is likely to form central symmetry during crystallization, In particular, it was discovered that a material for organic nonlinear optical elements having a large second-order nonlinear optical effect can be obtained, and the present invention was completed.

The above objects of the present invention are achieved by a novel cyclobutenedione derivative represented by the following general formula (I).

(In the formula, R1 and R2 represent an alkyl group, R3 represents any of the following formulas, and C* represents an asymmetric carbon atom) CH3C*HCH20H.

C2H3C*HCH20H.

C6H3CH2C*HCH20H.

H CH3C*HCH2- The synchronobutenedione ring contained in the cyclobutenedione derivative represented by the above general formula (I) of the present invention has a very thick absorption wavelength (intramolecular charge transfer absorption band) shown in the following examples.
As can be seen, it has a strong electron-withdrawing property comparable to that of a nitro group, and a long π-electron conjugated system. Therefore, the entire molecule tends to take a highly electrically polarized structure, which causes high nonlinearity.

Furthermore, in the cyclobutenedione derivative represented by the above general formula (I), when an amino acid derivative having an asymmetric carbon atom is introduced as a substituent, the dipole moment of the molecule itself is large. However, by controlling the orientation of molecules in the bulk structure and breaking the central symmetry, even greater optical nonlinearity can be developed.

The cyclobutenedione derivative represented by the above general formula (I) of the present invention can be easily synthesized in good yield according to the reaction formula shown below.

That is, the cyclobutenedione derivative represented by the general formula (II) is suspended or dissolved in a solvent such as acetone, tetrahydrofuran, methanol, ethanol, etc., and then (II) (III) is dissolved in the resulting suspension or solution. ) (I) (wherein, X represents a chlorine atom, a bromine atom, a methoxy group or an ethoxy group, R1 and R2 represent an alkyl group, and R
3 represents one of the following formulas) C23C*HCH20H
To 1 H CH3C*HCH2- , an amount of the amino acid derivative represented by the general formula (III) in an amount greater than the amount of light relative to the cyclobutenedione derivative is gradually added with stirring to react. The reaction usually proceeds rapidly, but it is possible to heat the reaction if necessary. If the product precipitates as the reaction progresses,
Filter, and if the product does not precipitate, concentrate it or add a suitable poor solvent to precipitate it.
. The obtained crystals are recrystallized from a solvent such as alcohol or acetone, or purified by sublimation, if necessary.

Instead of the amino acid derivative represented by the above general formula (III), acid addition salts thereof, such as hydrochloride, bromate, p
- Using toluenesulfonate as a raw material, react with a cyclobutenedione derivative represented by general formula (II) in the presence of a basic compound such as triethylamine or N-methylmorpholine in the same manner as above. It is also possible to synthesize by

The cyclobutenedione derivative represented by the above general formula (II) can be prepared by, for example, treating 1,2-dimethoxybenzene and dichlorocyclobutenedione with a Friedel-Crach solvent (e.g. carbon disulfide, nitrobenzene, chloride) in the presence of aluminum chloride. A method for obtaining chlorocyclobutenedione derivatives by mixing and stirring in methylene, etc.),
Alternatively, a dialkoxycyclobutenedione can be combined with a trialkyloxonium salt and a halogenated solvent in a 1,2
- A method of reacting with dimethoxybenzene to obtain an alkoxycyclobutenedione derivative, etc.

(Example 1) 1-(3',4'-dimethoxyphenyl)-2-(1'
-Hydroxymethyl-2'-phenylethylamino)-
Synthesis of cyclobutene-3,4-dione 0.6 g (2
, 4 mmol) in acetone was added 1 g of D-phenylalaninol, and stirring was continued for about 2 hours.

After the reaction was completed, 40 ml of water was added as a poor solvent, and the mixture was left standing in a refrigerator. Thereafter, by collecting the precipitated yellow crystals, 1-(3'
, 4'-dimethoxyphenyl)-2-(1-hydroxymethyl-2'-phenylethylamino)-cyclobutene-3,4-dione 0.5 g (1.4 mmol) was obtained as yellow crystals. The yield was 58%.

Melting point: 192°C Extreme absorption wavelength (λmax) + 358nm (CH2C
12) Elemental analysis HN Calculated value 68.65 5.76 3.81 Measured value 68.46 5.40 3.92 Examples (2 to 4) As the raw material, the column of general formula (II) in Table 1 The general formula in Table 1 was prepared in the same manner as described in Example 1, except that the cyclobutenedione derivative described in Table 1 and the amino acid derivative described in the column of general formula (III) were used. (I
) was synthesized.

Regarding the obtained product, elemental analysis values, maximum absorption wavelength (
λmax in CH2Cl2) and melting point were measured.

The results are shown in Table 2.

(Application example) A powder sample filled with the compound represented by the above structural formula (I-1) described in Example 1 in a glass cell was added
:YAG laser (wavelength 1.064μm, output 180mJ)
/pulse), 532 nm caused by SHG
Strong green scattered light was efficiently generated.

(Effects of the Invention) The cyclobutenedione derivative represented by the above general formula of the present invention is a novel compound, exhibits high nonlinearity, and has excellent heat resistance, light resistance, storage stability, and processability. Since it is a substance, it can be used to fabricate nonlinear optical elements such as optical wavelength conversion elements, optical shutters, high-speed optical switching elements, optical logic gates, optical transistors, etc.

Claims (3)

[Claims] (1) A cyclobutenedione derivative represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 and R_2 represent an alkyl group, and R_3
represents one of the following formulas, and C^* represents an asymmetric carbon atom) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (2) Cyclobutenedione according to claim 1, characterized in that a cyclobutenedione derivative represented by the following general formula (II) is reacted with an amino acid derivative represented by the following general formula (III). Method for producing derivatives. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, X represents a chlorine atom, bromine atom, methoxy group, or ethoxy group, and R_1 and R_2 represent an alkyl group) NH_2R_3(III) (In the formula, R_3 represents one of the following formulas, and C^* represents an asymmetric carbon atom) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (3) A patent characterized in that the cyclobutenedione derivative represented by the general formula (II) and the acid addition salt of the amino acid derivative represented by the general formula (III) are reacted in the presence of a basic compound. A method for producing a cyclobutenedione derivative according to claim 1.