Synthesis and Characterization of Rhodium(I) Complexes with P–N Donor Ligands and Their Catalytic Application in Transfer Hydrogenation of Carbonyl Group

Abstract

Three rhodium(I) complexes of the types [Rh(COE)Cl(η2‐L)] (1a,1b) and [RhCl(η2‐L) (η1‐L)] (1c), where L = P~N donor ligands 2‐[2‐(diphenylphosphino) ethyl]pyridine, (PPh2Etpy) (a), 2‐(diphenylphosphino)pyridine (PPh2py) (b), and 3‐(diphenylphosphino)‐1‐propylamine (PPh2(CH2)3NH2) (c), have been synthesized by reacting [Rh(coe)2Cl]2 with the respective ligands in 1:2 molar ratio for 1a, 1b and 1:4 molar ratio for 1c in DCM under refluxing condition. The complexes were characterized using different analytical techniques such as FT‐IR, ESI(+) mass spectrometry, 1H and 31P{ 1H} NMR spectrometry, conductivity measurements, and melting point determination. The synthesized complexes were found to exhibit good catalytic activity for the transfer hydrogenation of carbonyl compounds to corresponding alcohols with high conversion rate.