NEW ORGANIC NONLINEAR OPTICAL-CRYSTALS OF BENZYLIDENE-ANILINE DERIVATIVE

The benzylidene-aniline derivative with an electron-donating group at the 4-position and an electron-accepting group at the 4′-position has been suggested, by MO calculations, to have a small molecular dipole moment in spite of the large second-order hyperpolarizability, and hence to be a promising molecule in the search for new organic crystals with large second-order optical non-linearity. By modification of the molecule suggested, a series of crystals having high second-harmonic generation (SHG) activities have been discovered; one of them showed a larger powder SHG than 2-methyl-4-nitroaniline (MNA). © 1990.