SPECTROSCOPIC AND MAGNETIC STUDIES ON SOME COPPER(II) COMPLEXES OF ANTIPYRINE SCHIFF-BASE DERIVATIVES

A new series of copper(II) complexes derived from 4-(2-thienyl-methyli dene amino) antipyrine (TAAP) and 4-furfurylidene amino antipyrine (FA AP) have been synthesized. The complexes are formulated as [(TAAP)Cu]( ClO4)(2), [(FAAP)(2)Cu](ClO4)(2), [(FAAP)Cu(OH)Br], [L2CuX2]. nH(2)O a nd [L2Cu(NO3)(2)], L = TAAP or FAAP, X = Cl or Br and n = 2 or 1, base d on their elemental analyses and infrared spectral data. The infrared data indicate the bidentate nature of both ligands in all complexes e xcept in [(TAAP) Cu](ClO4)(2) when the ligand acts as a tridentate che lating agent. The electronic and EPR spectral data are used to interpr et the nature of bonding of the ligands with the copper(II) ion, groun d state and ligand held strength. The room temperature magnetic moment s indicate polymeric structure for [(TAAP)CuX2]. nH(2)O, [(TAAP)Cu](Cl O4)(2) and [(FAAP)Cu(OH)Br] and monomeric structure for the rest of th e complexes. The biological activity studies of the complexes and the free ligands towards three gram-positive, seven gramnegative bacteria and three fungal species have been studied and the potential is relate d to the nature and structure of the complexes. (C) 1997 Elsevier Scie nce Ltd.