Motonobu Morioka

Second-Harmonic Generation from Single Crystals of N-Substituted 4-Nitroanilines

Six N-substituted derivatives of 2-methyl-4-nitroaniline (MNA) and two N-substituted derivatives of 4-nitroaniline were synthesized and their physical and optical properties were examined in the search for nonlinear optical materials with a sufficiently large second harmonic (SH) activity and applicability to practical use. Some derivatives produced single crystals and their structures were determined by X-ray crystallography. The trends of the SH intensity of these materials could be qualitatively explained based on the b tensor (the effective molecular hyperpolarizability in the crystal). Amongst the derivatives examined in this investigation, N-benzyl-MNA showed the highest SH activity (up to twice that of MNA), thermostability and phase-matching ability.

Chemical actinometer with 2-hydroxy-4′-dimethylaminochalcone

Abstract The quantum yield of photochemical conversion of 2-hydroxy-4′-dimethylaminochalcone into 4′-dimethylaminoflavylium ion is approximately 0.23 in tetrahydrofuran solution in the presence of 5 mM p -toluenesulphonic acid on irradiation with UV light. The quantum yield is essentially constant as a function of the reaction conditions, such as the reaction time, temperature, substrate concentration and light intensity, but the absorption spectra of the reactant and product are well separated. These features are favourable for use as a chemical actinometer.