Isoxazolone-based single crystals with large second harmonic generation effect

Abstract

Two nonlinear optical (NLO) crystals based on the 3-phenyl-5-isoxazolone moiety, (Z)-4-(4-(dimethylamino)benzylidene)-3-phenylisoxazol-5(4H)-one (C₁₈H₁₆N₂O₂, DLS) and (Z)-4-(4-methoxybenzylidene)-3-phenylisoxazol-5(4H)-one (C₁₇H₁₃NO₃, MLS), have been successfully grown by a slow evaporation method. The powder second-harmonic generation intensities of DLS and MLS are strong, about 2.8 and 1.5 times that of OH1, respectively. Such a large SHG effect is further elucidated by structure analyses and theoretical calculations. The optical and thermal properties of DLS and MLS have been characterized by UV-vis absorption spectroscopy, IR spectroscopy, thermal gravimetric analysis and differential scanning calorimetry.