Dinuclear, tetranuclear and polymeric complexes in copper(II) perchlorate/pyridine-2,6-diamidoxime chemistry: synthetic, structural and magnetic studies

Abstract

The initial use of pyridine-2,6-diamidoxime (pdamoH2) in metal cluster and polymer chemistry is described. Depending on the reaction conditions employed, the Cu(ClO4)2·6H2O/pdamoH2 system has provided access to the dinuclear compound [Cu2(pdamoH)2(ClO4)2(MeOH)2] (1), the chain-like polymer [Cu2(pdamoH)2]n(ClO4)2n (2) and to the tetranuclear cluster [Cu4(pdamo)2(pdamoH)2](ClO4)2 (3). Single-crystal, X-ray crystallography reveals different coordination modes for the pdamoH- ligand in each compound, providing the first evidence for the flexibility and versatility of the anionic forms of pdamoH2. Variable-temperature magnetic susceptibility studies indicate very strong antiferromagnetic coupling in the three complexes, attributable to the double oximato bridges which link the CuII spin carriers.