Syntheses, electronic structure, and second-order optical nonlinearity of two new bidentate monoazo Schiff-base compounds

Two new bidentate salicylaldiminato Schiff-base ligands have been synthesized by condensation of carious precursor ligands and n-propylamine. The results of elemental analysis are in conformity with the suggested formula. The main bands in IR spectra, signals in H-1 NMR and electronic absorption spectra are assigned and discussed in terms of molecular structure. Semiempirical calculations of the structures and second-order nonlinear optical polarizabilities (beta) of molecules were performed. The beta value for one of these Schiff-base compounds is 134 times that of urea.