New Schiff base zinc(ii) complexes exhibiting second harmonic generation

Abstract

Four bis(salicylaldiminato)zinc(II) complexes have been synthesized from four Schiff bases obtained by the condensation of chiral (R)-(+)-1-phenylethylamine with salicylaldehyde (1), 5-nitrosalicylaldehyde (2), 3,5-dichlorosalicylaldehyde (3) and 5-methoxysalicylaldehyde (4). The complexes crystallize in the noncentrosymmetric space groups P2₁2₁2₁ (1), P2₁ (2), and C2 (3, 4). The geometry around the zinc(II) metal center is pseudo-tetrahedral with two oxygen and two nitrogen atoms from the ligands and has the Λ absolute configuration. Powders of the four compounds exhibit second harmonic generation (SHG) of intensity between that of 3-methyl-4-nitropyridine-1-oxide (POM) and N-(4-nitrophenyl)-(S)-prolinol (NPP).