Cu(II)-Na(I) heterometallic coordination compounds as photocatalyst for degradation of methylene blue

Abstract Two new Cu(II)/Na(I) coordination polymers, namely, {[(Cu(L1)Na)2(ox)(ClO4)2]∙dmf}n (1) and {[(Cu(L2)Na)2(nph)]∙H2O}n (2) were synthesized by using the Schiff base N-(2-hydroxyethoxy)ethyl-iminomethyl-phenol (H2L1) with oxalate (ox) and (3-methoxy-2-hydroxybenzylidene)propanoic acid (H2L2) with naphthalene-2,6-dicarboxylateanions (nph), respectively. Both the complexes were characterized using elemental analysis, FT-IR, UV-vis spectroscopic analysis. The solid state structures of complexes 1-2 were determined using single crystal X-ray crystallography that revealed for 1 the presence of dinuclear copper(II) species, [(L1)Cu(ox)Cu(L1)], while 2 consists of stair-like 1D -[CuL2]2-(nph)]n- polymers. Both these fragments are further connected by Na(I) cations to form 2D supramolecular assemblies. In both the compounds the copper and sodium atoms exhibit a square pyramidal and a distorted octahedral coordination geometry, respectively. The catalytic activity of complexes 1-2 for the degradation of methylene blue (MB) was investigated under UV irradiation and in the presence of very small amount of H2O2. Both the compounds were found to be photo-catalytically active, and the mechanism of photocatalysis has been discussed in detail.