An integrated experimental and theoretical investigation of the structural and spectroscopic properties of two nickel(II) isothiosemicarbazone complexes

Abstract

Two nickel(II) isothiosemicarbazone complexes of dianionic 5-bromosalicylaldehyde S-allyl isothiosemicarbazonehydrobromide (H 2L.HBr), [Ni(Im)L] and [Ni(2-MeIm)L] (Im: imidazole, 2-MeIm: 2-methylimidazole), were synthesized and characterized by single crystal X-ray crystallography, 1H NMR spectrometry, IR, and electronic spectroscopy. The complexes have square-planar geometry and the ligand is coordinated as a dinegative tridentate chelating agent via phenolic oxygen, isothioamide nitrogen, and azomethine nitrogen atoms. To complement the experimental data, density functional theory (DFT) and time-dependent DFT methods were used to validate the structural parameters and infrared and electronic spectra. © 2014 Taylor and Francis.