Three coordinated copper(I) complexes of chelating ligands derived from 2,6-diacetylpyridine and phenylalanine or tyrosine

Abstract

Copper(I) complexes of Schiff-base ligands, L1, and L2, derived from condensation of 2,6-diacetylpyridine with phenylalanine methyl ester or tyrosine ethyl ester have been prepared. On the basis of various spectroscopic data, it is proposed that these complexes in the solid-state have mononuclear structures in which the trimethine group acts as tridentate while retaining its planarity. In methanol, spectroscopic properties suggest at least partial dissociation of one-side arm leading to a two-coordinate copper(I) which then interacts with a free imino nitrogen of a second molecule of the copper(l) complex. This results in a more effective overlap of the copper(I) orbital with pπ* of the ligand and hence an increase in absorption intensities. © 1989.