Synthesis, crystal structure, Cu2+ doped EPR, thermal and voltammetric studies of [Ni(isonicotinamide)(2)(H2O)(4)] center dot (sac)(2) single crystal

Abstract

The single crystal of [Ni(ina)(2)(H2O)(4)] - (sac)(2), (NINS), (ina is isonicotinamide and sac is saccharinate) complex has been prepared and its structural, spectroscopic and thermal properties have been determined. The title complex crystallizes in monoclinic system with space group P2(1)/c, Z = 2. The octahedral Ni(II) ion, which rides on a crystallographic centre of symmetry, is coordinated by two monodentate ina ligands through the ring nitrogen and four aqua ligands to form discrete [Ni(ina)(2)(H2O)(4)] unit, which captures two saccharinate ions in up and down positions, each through intermolecular hydrogen bands. The magnetic environment of copper(II) doped NINS crystal has also been identified by electron paramagnetic resonance (EPR) technique. The g and A values Of Cu2+ doped NINS single crystal were calculated from the EPR spectra recorded in three mutually perpendicular planes. These values indicated that the paramagnetic centre has a rhombic symmetry with the Cu2+ ion having distorted octahedral environment. The complex exhibits only metal centred electroactivity in the potential range of -2.00, 1.25 V versus Ag/AgCl reference electrode. (C) 2007 Elsevier Ltd. All rights reserved.