Spectral, magnetic, thermal, molecular modelling, ESR studies and antimicrobial activity of (E)-3-(2-(2-hydroxybenzylidene)hydrazinyl)-3-oxo-n(thiazole-2-yl)propanamide complexes

(E)-3-(2-(2-hydroxybenzylidene)hydrazinyl)-3-oxo-n(thiazole-2-yl) propane-mide (H2L) has been prepared and its structure confirmed by elemental analysis, IR and (HNMR)-H-1 spectroscopy. It has been used to produce diverse complexes with Ni(II), Co(II) and Cu(II) ions. The complexes obtained have been investigated by thermal analysis, spectral studies (IR, UV-visible. ESR). and magnetic measurements. IR spectra suggest that the H2L acts as a bidentate ligand coordinating via (C=N)(1), and (OH)(phenolic) or deprotonated enolized carbonyl oxygen (=C-O-)(1). The electronic spectra of the complexes and their magnetic moments provide information about geometries. The room temperature solid state ESR spectra of the Cu(II) complexes show d(x2-y2) as a ground state, suggesting tetragonally distorted octahedral or square-planar geometries around Cu(II) centre. The molar conductance measurements proved that the complexes are non-electrolytes. The bond length, bond angle, HOMO, LUMO, dipole moment and charges on the atoms have been calculated to confirm the geometry of the ligand and the investigated complexes. Also, thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters (Ea, A, Delta H, Delta S and Delta G) of all thermal decomposition stages have been evaluated using Coats-Redfern and Horowitz-Metzger methods. Finally, the antimicrobial activity has been tested. (C) 2011 Elsevier B.V. All rights reserved.