HYDRAZONE DERIVATIVES, AN EFFICIENT CLASS OF CRYSTALLINE MATERIALS FOR NONLINEAR OPTICS

We report on the synthesis and optical characterization of hydrazone d erivatives developed for second-order nonlinear optics. Electric-field -induced second harmonic generation (EFISH) as well as semiempirical q uantum-chemical computations have been carried out to investigate and explain the nonlinear optical properties of these molecules. We obtain ed values of up to 220 x 10(-40) m(4)/V for the molecular hyperpolariz ability beta at lambda = 1907 nm. The investigation of a series of 39 hydrazone derivatives with the second harmonic generation powder test according to Kurtz and Ferry revealed that an extraordinarily large fr action of these hydrazones show efficient second-order nonlinear activ ity. Among them, dimethylamino)-benzaldehyde-4-nitrophenylhydrazone (D ANPH) and zacycloheptyl)-benzaldehyde-4-nitrophenylhydrazone (ACNPH) w ere selected for more detailed investigations. Their crystalline struc tures are presented, and the role played by hydrogen bonds in their mo lecular packing is emphasized. Finally, preliminary linear and nonline ar optical data of DANPH crystals are reported.