Synthesis of Transition Metal Carbonyl Clusters with Phosphine ligands

Abstract

The chemistry of transition metal chalcogenide polynuclear clusters is a rapidly expanding area. The increasing interest is due to the search for structural models and precursors of extended inorganic solids with novel electronic, magnetic and optical properties. Our interest for the synthesis of a variety of transition –metal clusters is due to their use as a model and precursors for materials and catalyst. Synthesis and study of a variety of ligand substituted iron carbonyl cluster has been carried out to understand the reactivity features and structural variety. The main focus has been on the transition metal clusters containing chalcogens which act as bridges between different metal fragments and are helpful in cluster growth reactions and maintains the cluster integrity. A synthetic strategy has been developed to prepare a mixed metal cluster when a dichloromethane solution of [Fe3Y2(CO)6],Y=S, Se, Te and ML4 (M=Pd ,L=PPh3) was reacted at room temperature in presence of trimethylamine-N-oxide. Substitution reaction of carbonyl groups by triphenylphosphine and bis(diphenylphosphino)methane ligands results in the formation of different types of trinuclear clusters. Homo metallic cluster as well mixed metal clusters with phosphine ligands has been synthesized by a room temperature reaction and characterized by FTIR, proton and 31P NMR spectroscopy. Some of the transition metal cluster contains chelating phosphine ligands which stabilizes the cluster integrity.