NONLINEAR OPTICAL MATERIAL

Abstract: A nonlinear optical material, which comprises a chalcone derivative of general for­ mula (I) or (II), wherein R₁ and R₂ each repre­ sents a halogen atom, a hydroxy group, an am­ ino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an ace­ tyl group, an alkyl group having 1 to 18 car­ bon atoms or an alkyloxy group having 1 to 22 carbon atoms, n₁ and n₂ each represents an in­ teger of 0 to 21, and m₁ and m₂ each represents an integer of 0 to 5.

Description: Field of Art : The present invention relates to a non-linear optical material comprising a derivative of chalcone. Background of Art : Non-linear optical materials are the materials exhibiting so-called non-linear optical effects, in which non-linear responses are resulted from induced polarization of electrons by the electric field created by the light incident to the materials, such effects being generally due to the second and higher order terms in the following equation of: P = κ (1) E + κ (2) E·E + κ (3) E·E·E + ------ + κ (n) E n wherein P is polarizability of a material, E is intensity of electric field, and κ (n) is non-linear sensitivity of the n-th order It has been known from "American Chemical Society Symposium Series 233 (1983)" p. 57-80 that due to a phenomenon known as the second harmonic generation (SHG) obtained by the specific utilization of the secondary effect, an incident light is converted into a light wave corresponding to the second harmonic wave and having a frequency twice as high as the frequency of the incident light or the refractive index is changed by voltage, so that the phenomenon is very conveniently utilized for performing various optical processings including conversion of wave lengths, processing of signals and modulation of laser beams, which are extremely advantageous. Although inorganic crystals, such as KH₂PO₄ (KDP), LiNbO₃, or NH₄H₂PO₄ (ADP), have hitherto been used as the non-linear optical materials, they have disadvantages that single crystals having high optical purities are very expensive, that they are so deliquescent as to be inconvenient in handling, and that the non-linear sensitivities thereof are not so high. On the other hand, since the utility of organic materials was suggested in 1983 in the symposium in the American Chemical Society, organic crystals of urea, aniline base compounds or the like were reported to be utilizable as non-linear optical materials. However, these organic compounds do not exhibit satisfactory non-linear optical effect, or the compounds which exhibit relatively high level of non-linear effect have a disadvantage that they have light absorptive terminal groups that are significantly shifted to the long wavelength range to thus limit the wavelength range of the light waves which can be processed therethrough. Soviet Journal of Quantum Electronics vol. 12, pages 214-215 (1982) describes 4'-methoxybenzalacetophenone as a non-linear optical material. Nonlinear Optical Properties of Organic Molecules and Crystals, vol. 2, page 247, describes a derivative of chalcone (4-methoxybenzalacetophenone) used as a non-linear optical material. An object of the present invention is to provide a non-linear optical material comprising a derivative of chalcone, which is excellent in transmittance and transparency and exhibits exceedingly high non-linear effect. Disclosure of the Invention : According to the present invention, there is provided a non-linear optical material comprising a derivative of chalcone represented by the following general formula (I) of: wherein R₁ is a halogen atom, a hydroxyl group, an amino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an acetyl group, an alkyl group having 1 to 18 carbon atoms or an alkyloxy group having 1 to 22 carbon atoms; n₁ is an integer of from 0 to 21; and m₁ is an integer of from 0 to 5. Also provided by the present invention is a non-linear optical material comprising a derivative of chalcone represented by the following genral formula (II) of: wherein R₂ is a halogen atom, a hydroxyl group, an amino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an acetyl group, an alkyl group having 1 to 18 carbon atoms or an alkyloxy group having 1 to 22 carbon atoms; n₂ is an integer of from 0 to 21; and m₂ is an integer of from 0 to 5. Brief Description of the Drawing : Fig. 1 is a graph showing the light absorption spectrum of a purified product of 4-methylthiochalcone which is one of the non-linear optical materials of this invention and the light absorption spectrum of a known non-linear optical material; and Fig. 2 is a graph showing the light absorption spectrum of a purified product of 3-bromo-4′-methylthiochalcone which is one of the non-linear optical materials of this invention and the light absorption spectrum of a known non-linear optical material. Preferred Embodiments to Practise the Invention : The present invention will be described in detail below. In the following general formula (I) of: used in the present invention, R₁ is a halogen atom, a hydroxyl group, an amino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an acetyl group, an alkyl group having 1 to 18 carbon atoms or an alkyloxy group having 1 to 22 carbon atoms; n₁ is an integer of from 0 to 21; and m₁ is an integer of from 0 to 5. In the following general formula (I) of: used in the present invention, R₂ is a halogen atom, a hydroxyl group, an amino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an acetyl group, an alkyl group having 1 to 18 carbon atoms or an alkyloxy group having 1 to 22 carbon atoms; n₂ is an integer of from 0 to 21; and m₂ is an integer of from 0 to 5. Compounds represented by the formulae wherein n₁ and n₂ are not less than 22 cannot be used because of the difficulty in production thereof; and compounds represented by the formulae wherein R₁ and R₂ are alkyl groups each having not less than 19 carbon atoms or alkyloxy groups each having not less than 23 carbon atoms cannot be used likewise because of the difficulty in production thereof. The derivatives of chalcone used in the present invention as the non-linear optical materials and represented by the general formula (I) or (II) set forth above may be prepared through condensation reactions in the presence of a basic or acidic catalyst, for example, by reacting derivatives of thiobenzaldehyde, such as 4-methylthiobenzaldehyde, 4-ethylthiobenzaldehyde or 4-propylthiobenzaldehyde, with acetophenone or derivatives thereof for the compounds represented by the general formula (I), and by reacting derivatives of thioacetophenone such as 4-methylthioacetophenone, 4-ethylthioacetophenone or 4-propylthioacetophenone, with benzaldehyde or derivatives thereof for the compounds represented by the general formula (II). For example, sodium hydroxide, potassium hydroxide and various quaternary ammonium salts may be used as the basic catalysts, and boron trifluoride, phosphorus oxychloride and boron trifluoride etherate may be used as the acidic catalysts. In addition, it is preferred that a proper solvent, for example alcohols such as methanol or ethanol may be used to proceed the condensation reaction at a temperature range within 0 to 50°C for 30 minutes to 10 hours. When the reaction temperature becomes higher than 50°C during the reaction, various side-reactions take place and when the reaction temperature becomes lower than 0°C, the reaction time is exceedingly prolonged, both being considered to be undesirable. Preferred derivatives of chalcone obtained according to this invention and represented by the general formula (I) include, for example, 4-methylthiochalcone, 4-methylthio-4′-chlorochalcone, 4-methylthio-4′-bromochalcone, 4-methylthio-4′-hydroxychalcone, 4-methylthio-4′-nitrochalcone, 4-methylthio-4′-aminochalcone, 4-methylthio-4′-dimethylaminochalcone, 4-methylthio-4′-methylchalcone, 4-methylthio-4′-ethylchalcone, 4-methylthio-4′-butylchalcone, 4-methylthio-4′-hexylchalcone, 4-methylthio-4′-octylchalcone, 4-methylthio-4′-decylchalcone, 4-methylthio-4′-dodecylchalcone, 4-methylthio-4′-tetradecylchalcone, 4-methylthio-4′-hexadecylchalcone, 4-methylthio-4′-octadecylchalcone, 4-methylthio-4′-methoxychalcone, 4-methylthio-4′-ethoxychalcone, 4-methylthio-4′-butoxychalcone, 4-methylthio-4′-hexyloxychalcone, 4-methylthio-4′-octyloxychalcone, 4-methylthio-4′-decyloxychalcone, 4-methylthio-4′-dodecyloxychalcone, 4-methylthio-4′-tetradecyloxychalcone, 4-methylthio-4′-hexadecyloxychalcone, 4-methylthio-4′-octadecyloxychalcone, 4-methylthio-3′-chlorochalcone, 4-methylthio-3′-bromochalcone, 4-methylthio-3′-hydroxychalcone, 4-methylthio-3′-nitrochalcone, 4-methylthio-3′-aminochalcone, 4-methylthio-3′-dimethylaminochalcone, 4-methylthio-3′-methylchalcone, 4-methylthio-3′-ethylchalcone, 4-methylthio-3′-butylchalcone, 4-methylthio-3′-hexylchalcone, 4-methylthio-3′-octylchalcone, 4-methylthio-3′-decylchalcone, 4-methylthio-3′-dodecylchalcone, 4-methylthio-3′-tetradecylchalcone, 4-methylthio-3′-hexadecylchalcone, 4-methylthio-3′-octadecylchalcone, 4-methylthio-3′-methoxychalcone, 4-methylthio-3′-ethoxychalcone, 4-methylthio-3′-butoxychalcone, 4-methylthio-3′-hexyloxychalcone, 4-methylthio-3′-octyloxychalcone, 4-methylthio-3′-decyloxychalcone, 4-methylthio-3′-dodecyloxychalcone, 4-methylthio-3′-tetradecyloxychalcone, 4-methylthio-3′-hexadecyloxychalcone, 4-methylthio-3′-octadecyloxychalcone, 4-methylthio-4′-fluorochalcone, 4-methylthio-3′,4′-dichlorochalcone, 4-methylthio-4′-nonylchalcone, 4-methylthio-4′-t-butylchalcone, 4-methylthio-4′-fluorochalcone, 4-ethylthio-4′-chlorochalcone, 4-ethylthio-4′-bromochalcone, 4-ethylthio-3′-bromochalcone, 4-ethylthio-4′-iodochalcone, 4-butylthio-4′-bromochalcone, 4-butylthio-4′-iodochalcone, 4-octylthio-4′-chlorochalcone and 4-octadecylthio-4′-bromochalcone. Preferred derivatives of chalcone obtained according to this invention and represented by the general formula (II) includes, for example, 4′-methylthiochalcone, 3-methyl-4′-methylthiochalcone, 4-chloro-4′-methylthiochalcone, 2,4-dichloro-4′-methylthiochalcone, 2,5-dichloro-4′-methylthiochalcone, 3,4-dichloro-4′-methylthiochalcone, 2,3,4-trichloro-4′-methylthiochalcone, 3,4,5-trichloro-4′-methylthiochalcone, 2,4,6-trichloro-4′-methylthiochalcone, 2,3,4,5-tetrachloro-4′-methylthiochalcone, 2,3,4,5,6-pentachloro-4′-methylthiochalcone, 2-fluoro-4′-methylthiochalcone, 3-fluoro-4′-methylthiochalcone, 4-fluoro-4′-methylthiochalcone, 2,3-difluoro-4′-methylthiochalcone, 3,4-difluoro-4′-methylthiochalcone, 2,5-difluoro-4′-methylthiochalcone, 3,5-difluoro-4′-methylthiochalcone, 2,4-difluoro-4′-methylthiochalcone, 2,6-difluoro-4′-methylthiochalcone, 2,3,4-trifluoro-4′-methylthiochalcone, 3,4,5-trifluoro-4′-methylthiochalcone, 2,4,6-trifluoro-4′-methylthiochalcone, 2,3,5-trifluoro-4′-methylthiochalcone, 2,3,6-trifluoro-4′-methylthiochalcone, 2,3,4,5-tetrafluoro-4′-methylthiochalcone, 2,3,4,6-tetrafluoro-4′-methylthiochalcone, 2,3,5,6-tetrafluoro-4′-methylthiochalcone, 2,3,4,5,6-pentafluoro-4′-methylthiochalcone, 2-bromo-4′-methylthiochalcone, 3-bromo-4′-methylthiochalcone, 4-bromo-4′-methylthiochalcone, 2,4-dibromo-4′-methylthiochalcone, 2,5-dibromo-4′-methylthiochalcone, 3,4-dibromo-4′-methylthiochalcone, 2,3,4-tribromo-4′-methylthiochalcone, 3,4,5-tribromo-4′-methylthiochalcone, 2,4,6-tribromo-4′-methylthiochalcone, 2,3,4,5-pentabromo-4′-methylthiochalcone, 2-iodo-4′-methylthiochalcone, 3-iodo-4′-methylthiochalcone 4-iodo-4′-methylthiochalcone, 2,3-diiodo-4′-methylthiochalcone, 2,4-diiodo-4′-methylthiochalcone, 3,4-diiodo-4′-methylthiochalcone, 3,5-diiodo-4′-methylthiochalcone, 2,3,4-triiodo-4′-methylthiochalcone, 3,4,5-triiodo-4′-methylthiochalcone, 2,4,6-triiodo-4′-methylthiochalcone, 3-hydroxy-4′-methylthiochalcone, 4-hydroxy-4′-methylthiochalcone, 2,3-dihydroxy-4′-methylthiochalcone, 2,4-dihydroxy-4′-methylthiochalcone, 2,5-dihydroxy-4′-methylthiochalcone, 2,6-dihydroxy-4′-methylthiochalcone, 3,4-dihydroxy-4′-methylthiochalcone, 2,3,4-trihydroxy-4′-methylthiochalcone, 2,3,5-trihydroxy-4′-methylthiochalcone, 2,3,6-trihydroxy-4′-methylthiochalcone, 2,4,5-trihydroxy-4′-methylthiochalcone, 2,4,6-trihydroxy-4′-methylthiochalcone, 3,4,5-trihydroxy-4′-methylthiochalcone, 2,3,4,5-tetrahydroxy-4′-methylthiochalcone, 2,3,4,6-tetrahydroxy-4′-methylthiochalcone, 2,3,5,6-tetrahydroxy-4′-methylthiochalcone, 2,3,4,5,6-pentahydroxy-4′-methylthiochalcone, 3-methoxy-4′-ethylthiochalcone, 3-dimethylamino-4′-methylthiochalcone, 3-octadecyl-4′-methylthiochalcone, 2,6-dimethoxy-4′-methylthiochalcone, 3-cyano-4′-methylthiochalcone, 3-methyl-4′-methylthiochalcone, 2,3-dimethyl-4′-ethylthiochalcone, 2,4-dimethyl-4′-ethylthiochalcone, 2,5-dimethyl-4′-ethylthiochalcone, 2,6-dimethyl-4′-ethylthiochalcone, 3,4-dimethyl-4′-ethylthiochalcone, 3,5-dimethyl-4′-ethylthiochalcone, 2,3,4-trimethyl-4′-ethylthiochalcone, 2,3,5-trimethyl-4′-ethylthiochalcone, 2,4,5-trimethyl-4′-ethylthiochalcone, 2,4,6-trimethyl-4′-ethylthiochalcone, 2,3,4,5-tetramethyl-4′-ethylthiochalcone, 2-ethyl-4′-ethylthiochalcone, 3-ethyl-4′-ethylthiochalcone, 4-ethyl-4′-ethylthiochalcone, 2,3-diethyl-4′-ethylthiochalcone, 2,4-diethyl-4′-ethylthiochalcone, 2,5-diethyl-4′-ethylthiochalcone, 3,4-diethyl-4′-ethylthiochalcone, 3,5-diethyl-4′-ethylthiochalcone, 2,3,4-triethyl-4′-ethylthiochalcone, 2,3,5-triethyl-4′-ethylthiochalcone, 3,4,5-triethyl-4′-ethylthiochalcone, 2-propyl-4′-ethylthiochalcone, 3-propyl-4′-ethylthiochalcone, 4-propyl-4′-ethylthiochalcone, 2,3-dipropyl-4′-ethylthiochalcone, 2,4-dipropyl-4′-ethylthiochalcone, 3,5-dipropyl-4′-ethylthiochalcone, 3,4,5-tripropyl-4′-ethylthiochalcone, 2-butyl-4′-ethylthiochalcone, 3-butyl-4′-ethylthiochalcone, 4-butyl-4′-ethylthiochalcone, 3,4-dibutyl-4′-ethylthiochalcone, 2-pentyl-4′-ethylthiochalcone, 3-pentyl-4′-ethylthiochalcone, 4-pentyl-4′-ethylthiochalcone, 2-hexyl-4′-ethylthiochalcone, 3-hexyl-4′-ethylthiochalcone, 4-hexyl-4′-ethylthiochalcone, 2-amino-4′-ethylthiochalcone, 3-amino-4′-ethylthiochalcone, 3,4-diamino-4′-ethylthiochalcone, 3,5-diamino-4′-ethylthiochalcone, 2-dimethylamino-4′-ethylthiochalcone, 3-dimethylamino-4′-ethylthiochalcone, 3,5-bis(dimethylamino)-4′-ethylthiochalcone, 3-bromo-4′-ethylthiochalcone, 3-nitro-4′-ethylthiochalcone, 3,5-dinitro-4′-ethylthiochalcone, 2-cyano-4′-ethylthiochalcone, 3-cyano-4′-ethylthiochalcone, 4-cyano-4′-ethylthiochalcone, 2,4-dicyano-4′-ethylthiochalcone, 3,4-dicyano-4′-ethylthiochalcone, 3-phenyl-4′-ethylthiochalcone, 4-phenyl-4′-ethylthiochalcone, 3,5-biphenyl-4′-ethylthiochalcone, 3-acetyl-4′-ethylthiochalcone, 4-acetyl-4′-ethylthiochalcone, 3,5-diacetyl-4′-ethylthiochalcone, 3-methoxy-4′-ethylthiochalcone, 2,3-dimethoxy-4′-ethylthiochalcone, 2,4-methoxy-4′-ethylthiochalcone, 2,5-dimethoxy-4′-ethylthiochalcone, 2,6-dimethoxy-4′-ethylthiochalcone, 3,4-dimethoxy-4′-ethylthiochalcone, 3,5-dimethoxy-4′-ethylthiochalcone, 2,3,4-trimethoxy-4′-ethylthiochalcone, 2,3,5-trimethoxy-4′-ethylthiochalcone, 2,3,6-trimethoxy-4′-ethylthiochalcone, 2,4,5-trimethoxy-4′-ethylthiochalcone, 2,4,6-trimethoxy-4′-ethylthiochalcone, 3,4,5-trimethoxy-4′-ethylthiochalcone, 2,3,4,5-tetramethoxy-4′-ethylthiochalcone, 2,3,4,6-tetramethoxy-4′-ethylthiochalcone, 2,3,5,6-tetramethoxy-4′-ethylthiochalcone, 2,3,4,5,6-pentamethoxy-4′-ethylthiochalcone, 2-ethoxy-4′-ethylthiochalcone, 3-ethoxy-4′-propylthiochalcone, 4-ethoxy-4′-propylthiochalcone, 2,3-diethoxy-4′-propylthiochalcone, 2,4-diethoxy-4′-propylthiochalcone, 2,5-diethoxy-4′-propylthiochalcone, 2,6-diethoxy-4′-propylthiochalcone, 2,3,4-triethoxy-4′-propylthiochalcone, 2,3,5-triethoxy-4′-propylthiochalcone, 2,4,5-triethoxy-4′-propylthiochalcone, 2-propyloxy-4′-propylthiochalcone, 3-propyloxy-4′-propylthiochalcone, 4-propyloxy-4′-propylthiochalcone, 3,4-dipropyloxy-4′-propylthiochalcone, 3,5-dipropyloxy-4′-propylthiochalcone, 3,4,5-tripropyloxy-4′-propylthiochalcone, 2-butoxy-4′-propylthiochalcone, 3-butoxy-4′-propylthiochalcone, 4-butoxy-4′-propylthiochalcone, 3,4-dibutoxy-4′-propylthiochalcone, 3,5-dibutoxy-4′-propylthiochalcone, 3,4,5-tributoxy-4′-propylthiochalcone, 2-pentyloxy-4′-propylthiochalcone, 3-pentyloxy-4′-propylthiochalcone, 4-pentyloxy-4′-propylthiochalcone, 3,4-dipentyloxy-4′-propylthiochalcone, 3,5-dipentyloxy-4′-propylthiochalcone, 3,4,5-tripentyloxy-4′-propylthiochalcone, 2-hexyloxy-4′-propylthiochalcone, 3-hexyloxy-4′-propylthiochalcone, 4-hexyloxy-4′-propylthiochalcone, 3,4-dihexyloxy-4′-propylthiochalcone, 3,5-dihexyloxy-4′-propylthiochalcone, 3,4,5-trihexyloxy-4′-propylthiochalcone, 2-heptyloxy-4′-propylthiochalcone, 3-heptyloxy-4′-propylthiochalcone, 4-heptyloxy-4′-propylthiochalcone, 3,4-diheptyloxy-4′-propylthiochalcone, 3,5-diheptyloxy-4′-propylthiochalcone, 3,4,5-triheptyloxy-4′-propylthiochalcone, 2-octyloxy-4′-propylthiochalcone, 3-octyloxy-4′-propylthiochalcone, 4-octyloxy-4′-propylthiochalcone, 3,4-dioctyloxy-4′-propylthiochalcone, 3,5-dioctyloxy-4′-propylthiochalcone, 3,4,5-trioctyloxy-4′-propylthiochalcone, 2-nonyloxy-4′-propylthiochalcone, 3-nonyloxy-4′-propylthiochalcone, 4-nonyloxy-4′-propylthiochalcone, 3,4-dinonyloxy-4′-propylthiochalcone, 3,5-dinonyloxy-4′-propylthiochalcone, 3,4,5-trinonyloxy-4′-propylthiochalcone, 2-decyloxy-4′-propylthiochalcone, 3-decyloxy-4′-propylthiochalcone, 4-decyloxy-4′-propylthiochalcone, 3,4-didecyloxy-4′-propylthiochalcone, 3,5-didecyloxy-4′-propylthiochalcone, 3,4,5-tridecyloxy-4′-propylthiochalcone, 2-dodecyloxy-4′-propylthiochalcone, 3-dodecyloxy-4′-propylthiochalcone, 4-dodecyloxy-4′-propylthiochalcone, 3,4-didodecyloxy-4′-propylthiochalcone, 3,5-didodecyloxy-4′-propylthiochalcone, 3,4,5-tridodecyloxy-4′-propylthiochalcone, 2-tridecyloxy-4′-propylthiochalcone, 3-tridecyloxy-4′-propylthiochalcone, 4-tridecyloxy-4′-propylthiochalcone, 3,4-di(tridecyloxy)-4′-propylthiochalcone, 3,5-di(tridecyloxy)-4′-propylthiochalcone, 3,4,5-tri(tridecyloxy)-4′-propylthiochalcone, 2-tetradecyloxy-4′-propylthiochalcone, 3-tetradecyloxy-4′-propylthiochalcone, 4-tetradecyloxy-4′-propylthiochalcone, 3,4-di(tetradecyloxy)-4′-propylthiochalcone, 3,5-di(tetradecyloxy)-4′-propylthiochalcone, 3,4,5-tri(tetradecyloxy)-4′-propylthiochalcone, 2-pentadecyloxy-4′-propylthiochalcone, 3-pentadecyloxy-4′-propylthiochalcone, 4-pentadecyloxy-4′-propylthiochalcone, 3,4-di(pentadecyloxy)-4′-propylthiochalcone, 3,5-di(pentadecyloxy)-4′-propylthiochalcone, 3,4,5-tri(pentadecyloxy)-4′-propylthiochalcone, 2-hexadecyloxy-4′-propylthiochalcone, 3-hexadecyloxy-4′-propylthiochalcone, 4-hexadecyloxy-4′-propylthiochalcone, 3,4-di(hexadecyloxy)-4′-propylthiochalcone, 3,5-di(hexadecyloxy)-4′-propylthiochalcone, 3,4,5-tri(hexadecyloxy)-4′-propylthiochalcone, 2-heptadecyloxy-4′-propylthiochalcone, 3-heptadecyloxy-4′-propylthiochalcone, 4-heptadecyloxy-4′-propylthiochalcone, 3,4-di(heptadecyloxy)-4′-propylthiochalcone, 3,5-di(heptadecyloxy)-4′-propylthiochalcone, 3,4,5-tri(heptadecyloxy)-4′-propylthiochalcone, 2-octadecyloxy-4′-propylthiochalcone, 3-octadecyloxy-4′-propylthiochalcone, 4-octadecyloxy-4′-propylthiochalcone, 3,4-di(octadecyloxy)-4′-propylthiochalcone, 3,5-di(octadecyloxy)-4′-propylthiochalcone, 3,4,5-tri(octadecyloxy)-4′-propylthiochalcone, 3-nonadecyloxy-4′-propylthiochalcone, 4-nonadecyloxy-4′-propylthiochalcone, 3,4-di(nonadecyloxy)-4′-propylthiochalcone, 3,5-di(nonadecyloxy)-4′-propylthiochalcone, 3-eicosyloxy-4′-propylthiochalcone, 4-eicosyloxy-4′-propylthiochalcone, 3,4-di(eicosyloxy)-4′-propylthiochalcone, 3,5-di(eicosyloxy)-4′-propylthiochalcone, 3-heneicosyloxy-4′-propylthiochalcone, 4-heneicosyloxy-4′-propylthiochalcone, 3,5-di(heneicosyloxy)-4′-propylthiochalcone, 3-docosyloxy-4′-propylthiochalcone, 4-docosyloxy-4′-propylthiochalcone, 3,5-di(docosyloxy)-4′-propylthiochalcone, 3-dimethylamino-4′-methylthiochalcone, 3-cyano-4′-methylthiochalcone, 4-methoxy-4′-butylthiochalcone, 4-chloro-4′-octylthiochalcone, 3-bromo-4′-ethylthiochalcone and 4-bromo-4′-octadecylthiochalcone. As has been described hereinabove, the chalcone derivatives of the invention as represented by the general formulae (I) and (II) exhibit exceedingly high non-linear optical effects, extremely high transmittances and superior transparencies, so that it is possible to provide various optical materials by the present invention. Examples : The present invetion will be described more in detail with reference to Examples and Comparative Examples, but it should be noted here that the invention is not limited to the Examples set forth below. Example 1 Into a reaction vessel charged were 1.52g (0.01 mol) of 4-methylthiobenzaldhyde and 1.20g (0.01 mol) of acetophenone together with 20 ml of ethanol, and a mixed solution of 1g of a 40% aqueous solution of sodium hydroxide and 10 ml of ethanol was dropwisely added at 25°C under agitation. After the completion of dropwise addition, the reaction proceeded for 30 minutes while maintaining the temperature at 25°C. After the reaction, 20 ml of a 0.5N aqueous hydrochloric acid solution was added and agitated to cease the reaction. A separated solid was filtered, rinsed with water for several times and dried to obtain a crude product. The crude product was recrystallized from ethanol to obtain 1.48g of a purified product of 4-methylthiochalcone. The yield was 58%. The melting point was 83°C. The absorption spectrum of the purified 4-methylthiochalcone is shown in Fig. 1. Example 2 Into a reaction vessel charged were 1.52g (0.01 mol) of 4-methylthiobenzaldhyde and 1.55g (0.01 mol) of 4′-chloroacetophenone together with 30 ml of ethanol to proceed the reaction at 30°C for an hour. Then, 20 ml of a 0.5N aqueous hydrochloric acid solution was added followed by agitation to cease the reaction, and a separated solid was filtered and rinsed with water for several times. The crude product was recrystallized from ethanol to obtain 1.30g of a purified product of 4-methylthio-4′-chlorochalcone. The yield was 45%. The melting point was 149°C. Example 3 Following the procedure as described in Example 2, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.99g (0.01 mol) of 4′-bromoacetophenone were charged, reacted and purified similarly, whereby 1.40g of purified 4-methylthio-4′-bromochalcone was obtained. The yield was 42%. And the melting point was 161°C. Example 4 Following the procedure described in Example 2, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.36g (0.01 mol) of 4′-hydroxyacetophenone were charged, reacted and purified similarly, whereby 0.64g of purified 4-methylthio-4′-hydroxychalcone was obtained. The yield was 24%. The melting point was 171°C. Example 5 Into a reaction vessel charged were 1.52g (0.01 mol) of 4-methylthiobenzaldhyde and 1.35g (0.01 mol) of 4′-aminoacetophenone together with 30 ml of ethanol, and a mixed solution of 1g of a 40% aqueous solution of sodium hydroxide and 10 ml of ethanol was dropwisely added at 25°C under agitation. After the completion of dropwise addition, the reaction proceeded for 30 minutes while maintaining the temperature at 25°C. After the reaction, 50 ml of water was added and agitated, and a separated solid was filtered, rinsed with water for several times and dried. The crude product was recrystallized from a mixed solvent of ethanol/benzene = 1/1 to obtain 1.15g of a purified product of 4-methylthio-4′-aminochalcone. The yield was 43%. The melting point was 168°C. Example 6 Following the procedure as described in Example 2, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.65g (0.01 mol) of 4′-nitroacetophenone were charged and reacted, followed by recrystallization from a mixed solvent of ethanol/benzene = 1/1, to obtain 1.66g of purified 4-methylthio-4′-nitrochalcone. The yield was 56%. And the melting point was 159.5°C. Example 7 Following the procedure as described in Example 5, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.63g (0.01 mol) of 4′-dimethylacetophenone were charged, reacted and purified similarly, whereby 1.28g of purified 4-methylthio-4′-dimethylaminochalcone was obtained. The yield was 43%. And the melting point was 150.5°C. Example 8 Following the procedure as described in Example 2, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.50g (0.01 mol) of 4′-methoxyacetophenone were charged, reacted and purified similarly to obtain 1.18g of purified 4-methylthio-4′-methoxychalcone. The yield was 42%. And the melting point was 112.5°C. Example 9 Following the procedure as described in Example 2, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.64g (0.01 mol) of 4′-ethoxyacetophenone were charged, reacted and purified similarly to obtain 1.31g of purified 4-methylthio-4′-ethoxychalcone. The yield was 44%. And the melting point was 107.5°C. Example 10 Into a reaction vessel charged were 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 3.88g (0.01 mol) of 4′-octadecyloxyacetophenone together with 40 ml of ethanol, and agitated at 50°C to dissolve the materials to be reacted thoroughly. A mixed solution of 1g of a 40% aqueous sodium hydroxide solution and 10 ml of ethanol was dropwisely added into the reaction vessel, and then the admixture was allowed to react at a temperature of 40°C for 8 hours. 20 ml of a 0.5N aqueous hydrochloric acid solution was then added, followed by agitation, to cease the reaction. A separated solid was filtered, rinsed with water for several times and dried to obtain a crude product. The crude product obtained was recrystallized from an ethanol solvent to obtain 4.00g of purified 4-methylthio-4′-octadecyloxychalcone. The yield was 77%. And the melting point was 104°C. Example 11 Following the procedure as described in Example 2, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.99g (0.01 mol) of 3′-bromoacetophenone were charged, reacted and purified similarly to obtain 1.50g of purified 4-methylthio-3′-bromochalcone. The yield was 45%. And the melting point was 148°C. Example 12 Following the procedure as described in Example 6, 1.52g (0.01 mol) of 4-methylthiobenzaldehyde and 1.65g (0.01 mol) of 3′-nitroacetophenone were charged, reacted and purified similarly to obtain 1.75g of purified 4-methylthio-3′-nitrochalcone. The yield was 59%. And the melting point was 150°C. Examples 13 to 26 Compounds of Examples 13 to 26 as set forth below were synthesized following the procedure as described in Example 1 except that different derivatives of thiobenzaldehyde and/or derivatives of acetophenone were used as the starting materials. Example 13 4-methylthio-4′-fluorochalcone Example 14 4-methylthio-3′-chlorochalcone Example 15 4-methylthio-3′,4′-dichlorochalcone Example 16 4-methylthio-4′-nonylchalcone Example 17 4-methylthio-4′-t-butylchalcone Example 18 4-ethylthio-4′-fluorochalcone Example 19 4-ethylthio-4′-chlorochalcone Example 20 4-ethylthio-4′-bromochalcone Example 21 4-ethylthio-3′-bromochalcone Example 22 4-ethylthio-4′-iodochalcone Example 23 4-butylthio-4′-bromochalcone Example 24 4-butylthio-4′-iodochalcone Example 25 4-octylthio-4′-chlorochalcone Example 26 4-octadecylthio-4′-bromochalcone Example 27 Second harmonic generations (SHG) of the derivatives of chalcone synthesized in Examples 1 to 26 and the derivatives of chalcone synthesized by the similar processes were measured. The measuring method used involved the steps of putting each granulated sample having a diameter of 50 to 150 µm between slide glass plates, subjecting the sample to pulses of 15 nsec. from a Nd-YAG laser source (Wavelength: 1064 nm) fitted with a Q switch, and measuring the second harmonic wave generated from the sample. The standard sample used was urea which had been granulated similarly, and the SHG intensity ratio of each sample was determined when the SHG intensity of urea was set to 1. This measuring method has been well known to a person having ordinary skill in the art, and reference may be had, for example, to Journal of Applied Physics, vol. 36, pp 3798 to 3813 (1968). The SHG intensity ratios of the derivatives of chalcone, according to the present invention, measured by the method described above are shown in Table 1. Comparative Example 1 Using 2-methyl-4-nitroaniline which was a known non-linear optical material, the light absorption spectrum was measured. The results are shown in Fig. 1. As will be apparent from Fig. 1, the chalcone derivatives had substantially 100% transmissions for visible lights having wavelengths of not less than 400 nm to reveal that they were essentially transparent. On the contrary, 2-methyl-4-nitroaniline, the known non-linear optical material, absorbed visible lights having wavelengths of not more than 500 nm to hinder transmission of the light. Example 28 Into a reaction vessel charged were 1.66g (0.01 mol) of 4′-methylthioacetophenone and 1.85g (0.01 mol) of 3-bromobenzaldehyde together with 20 ml of ethanol, and uder agitation added dropwisely was a mixed solution of 1g of a 40% aqueous solution of sodium hydroxide and 10 ml of ethanol at 20°C. After the completion of dropwise addition, the reaction proceeded for 30 minutes while maintaining the temperature at 20°C. Then, 20 ml of a 0.5N aqueous hydrochloric acid solution was added and agitated to cease the reaction, and then a separated solid was filtered to obtain a solid material which was rinsed with water for several times and dried to obtain a crude product. The crude product was recrystallized from an ethanol solvent to obtain 2.36g of a purified product of 3-bromo-4′-methylthiochalcone. The yield was 71%. The melting point was 180°C. The absorption spectrum of the aforementioned purified 3-bromo-4′-methylthiochalcone is shown in Fig. 2. Examples 29 to 42 Compounds of Examples 29 to 42 as set forth below were synthesized following the procedure as described in Example 1 except that different derivatives of thioacetophenone and/or derivatives of benzaldehyde were used as the starting materials. Example 29 3-methoxy-4′-methylthiochalcone Example 30 4-methylthiochalcone Example 31 3-dimethylamino-4′-methylthiochalcone Example 32 4-bromo-4′-methylthiochalcone Example 33 3-chloro-4′-methylthiochalcone Example 34 3-octadecyl-4′-methylthiochalcone Example 35 3-fluoro-4′-methylthiochalcone Example 36 3-methyl-4′-methylthiochalcone Example 37 2,6-dimethoxy-4′-methylthiochalcone Example 38 3-cyano-4′-methylthiochalcone Example 39 3-bromo-4′-ethylthiochalcone Example 40 4-methoxy-4′-butylthiochalcone Example 41 4-chloro-4′-octylthiochalcone Example 42 4-bromo-4′-octadecylthiochalcone Example 43 Second harmonic generations (SHG) of the derivatives of chalcone synthesized in Examples 28 to 42 were measured similaraly as in Example 27. The results are shown in Table 2. Comparative Example 2 Using 2-methyl-4-nitroaniline which was a known non-linear optical material, the light absorption spectrum was measured. The result is shown in Fig. 2.

Claims: A non-linear optical material comprising a derivative of chalcone represented by the following general formula (I) of: wherein R₁ is a halogen atom, a hydroxyl group, an amino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an acetyl group, an alkyl group having 1 to 18 carbon atoms or an alkyloxy group having 1 to 22 carbon atoms; n₁ is an integer of from 0 to 21; and m₁ is an integer of from 0 to 5. The non-linear optical material as claimed in claim 1, wherein said derivative of chalcone is selected from the group consisting of 4-methylthiochalcone, 4-methylthio-4'-chlorochalcone, 4-methylthio-4'-bromochalcone, 4-methylthio-4'-hydroxychalcone, 4-methylthio-4'-aminochalcone, 4-methylthio-4'-nitrochalcone, 4-methylthio-4'-dimethylaminochalcone, 4-methylthio-4'-methoxychalcone, 4-methylthio-4'-ethoxychalcone, 4-methylthio-4'-octadecyloxychalcone, 4-methylthio-3'-bromochalcone, 4-methylthio-3'-nitrochalcone, 4-methylthio-4'-fluorochalcone, 4-methylthio-3'-chlorochalcone, 4-methylthio-3',4'-dichlorochalcone, 4-methylthio-4'-nonylchalcone, 4-methylthio-4'-t-butylchalcone, 4-ethylthio-4'-fluorochalcone, 4-ethylthio-4'-chlorochalcone, 4-ethylthio-4'-bromochalcone, 4-ethylthio-3'-bromochalcone, 4-ethylthio-4'-iodochalcone, 4-butylthio-4'-bromochalcone, 4-butylthio-4'-iodochalcone, 4-octylthio-4'-chlorochalcone and 4-octadecylthio-4'-bromochalcone. A non-linear optical material comprising a derivative of chalcone represented by the following general formula (II) of: wherein R₂ is a halogen atom, a hydroxyl group, an amino group, a dimethylamino group, a nitro group, a cyano group, a phenyl group, an acetyl group, an alkyl group having 1 to 18 carbon atoms or an alkyloxy group having 1 to 22 carbon atoms; n₂ is an integer of from 0 to 21; and m₂ is an integer of from 0 to 5. The non-linear optical material as claimed in claim 3, wherein said derivative of chalcone represented by the general formula (II) is selected from the group consisting of 3-bromo-4'-methylthiochalcone, 3-methoxy-4'-methylthiochalcone, 4'-methylthiochalcone, 3-dimethylamino-4'-methylthiochalcone, 4-bromo-4'-methylthiochalcone, 3-chloro-4'-methylthiochalcone, 3-octadecyl-4'-methylthiochalcone, 3-fluoro-4'-methylthiochalcone, 3-methyl-4'-methylthiochalcone, 2,6-dimethoxy-4'-methylthiochalcone, 3-cyano-4'-methylthiochalcone, 3-bromo-4'-ethylthiochalcone, 4-methoxy-4'-butylthiochalcone, 4-chloro-4'-octylthiochalcone and 4-bromo-4'-octadecylthiochalcone.

Inventors: GOTO YOSHITAKA, HAYASHI AKIO, MIYATA SEIZO, NAKAYAMA MASAHARU, WATANABE TOSHIYUKI, GOTO, YOSHITAKA, HAYASHI, AKIO, MIYATA, SEIZO, NAKAYAMA, MASAHARU, WATANABE, TOSHIYUKI
Applicants: NIPPON OILS & FATS CO LTD, NIPPON OIL AND FATS COMPANY, LIMITED
Application year: 1988
Main classification: G02F1
IPC codes: G02F1