Synthesis and Characterisation of Poly (Vinylpyrrolidone) – Nickel (II) Complexes

Abstract

Main use of polymer - metal complexes lies in their ability to act as catalysts. In the proposed work we have selected poly (vinyl pyrrolidone) as ligand for complexing with nickel. Poly (vinyl pyrrolidone) is a water soluble polymer having a large number of consumer and environment friendly uses which are the consequences of its unique properties like biological compatibility, low toxicity, film forming ability, complexing ability, resistance to thermal degradation in solution and relatively inert behavior towards salts and acids. Nickel, being a transition metal, shows very good catalytic properties. Nickel based catalysts meet the criteria required for the catalysis of a wide range of chemical reactions. Polymer-metal complexes of poly (vinylpyrrolidone) and nickel were prepared by using aqueous solution of PVP (30K) and alcoholic solution of nickel chloride hexahydrate (NiCl2 ∙ 6H2O) at room temperature with different molar compositions. The polymer-metal complexes were obtained in crystalline form by evaporation of the solvent. They were characterized by solubility studies, FTIR, 1 H - NMR and 13 C - NMR. Procedure was repeated with aqueous solution of the salt also. The spectral analysis of the reactants and the polymer-metal complexes confirmed the formation of expected complexes. The conditions for better complexation were optimized.