Synthesis of A Novel Metal-Complex and its Polyoxometalate Based Hybrid by Solvothermal Method: Characterization and Study of their Catalytic Activity

Abstract

A novel ruthenium metalated complex has been synthesized by co-ordinating bipyridyl molecules and 4-aryl substituted thiosemicarbazide N-(4-nitrophenyl)hydrazinecarbothioamide ligand to ruthenium(II) metal center.Phosphotungstic acid (H3PW12O40) was used to immobilize the ruthenium complex [Ru(bpy)2(4-(p-NO2)C6H4TA)](ClO4)2 by solvothermal method, thus producing an organic-inorganic hybrid. The [Ru(bpy)2(4-(p-NO2)C6H4TA)](ClO4)2 and organic-inorganic hybrid [Ru(bpy)2(4-(p-NO2)C6H4TA)][HPW12O40] were characterized by elemental analysis, FT-IR,powder-XRD and DRUV-Vis. The change in surface morphology after the formation of hybrid from metal complex was investigated by SEM images. EDX analysis of hybrid [Ru(bpy)2(4-(p-NO2)C6H4TA)][HPW12O40] has shown that the monomeric unit of [Ru(bpy)2(4-(p-NO2)C6H4TA)](ClO4)2 has combined with [H3PW12O40] Keggin unit. Molecular formula of the hybrid was auxiliary confirmed by Inductively Coupled Plasma (ICP) technique. Both the metal complex and the hybrid are studied for oxidative catalytic conversion of alkyl aromatic and cycloalcohols. [Ru(bpy)2(4-(p-NO2)C6H4TA)][HPW12O40] has exhibited better catalytic activity in terms of selectivity and conversion percentage as compared to [Ru(bpy)2(4-(p-NO2)C6H4TA)](ClO4)2. Ru(bpy)2 (4-(p-NO2)C6H4TA)][HPW12O40] was reused multiple times. The products formed during catalysis were identified by mass spectroscopy and gas chromatography.