Synthesis and structure of aqua-2,2-(2,6-pyridindiyldiethylidene) dioxamohydrazide-copper(II) hydrate

Abstract

In a template synthesis from copper(II) acetate, 2,6-diacetylpyridine, and semioxamazide (NH2CO CONHNH2), two new copper(II) complexes, [Cu(dapsox)(H2O)]. H2O and [Cu(Hdapsox)(H2O)]ClO4, (where H(2)dapsox = 2,2-(2,6-pyridindiyldiethylidene)dioxamohydrazide) were obtained and characterized. The structure of the former complex was determined by a single-crystal X-ray analysis. Cu-II is located in a square pyramidal environment. The polydentate ligand, dapsox(2-), is coordinated in dianionic form, as an unsymmetrical quadridentate planar system forming one six-membered and two five-membered metal-chelate rings. The fifth coordination site is occupied by a water molecule. (C) 1997 Elsevier Science Ltd.