Preparation and characterization of the seven coordinate cadmium(II) complex [Cd(3,4-H2dhb)2(H2O) 3]·HCl·(3,4-H3dhb)·2.5H2O; the first structural determination of a complex containing the 3,4-dihydroxybenzoato(-1)(3,4-H2dhb-) ligand

Abstract

The 1:2:1 reaction of CdCl2·2.5H2O with 3,4-dihydroxybenzoic acid (3,4-H3dhb) and KOH in PrnOH-H2O gave the unique, seven-coordinate cadmium(II) complex [Cd(3,4-H2dhb)2(H2O) 3]·HCl·(3,4-H3dhb)·2.5H2O as one of the products. Crystal structure and 13Cd NMR studies showed that 3,4-H2dhb- behaves as a bidentate chelate with ligated atoms being the carboxylate oxygens, but that seven-coordination is not retained in aqueous solution. Copyright © 1997 Elsevier Science Ltd