Synthesis of a rhodium(I) carbonyl complex with a chiral aminodiphosphine ligand and its immobilization onto aminopropyl functionalized silica gel

Abstract

The reaction of [Rh(CO)2(µ-Cl)]2 with two molar equivalents of a chiral ligand, (R)-N,N-bis(2-diphenylphosphinoethyl)-1-phenylethylamine(PNP*) yield a mono-carbonyl complex, [Rh(CO)Cl(η2-P,P-PNP*)] (1), in which the potentially tridentate PNP* ligand coordinates in a bidentate fashion through P,P bonding. The complex was characterized by elemental analysis, FAB mass, IR, UV-Vis, 1H- and 31P{1H}-NMR spectroscopy. Variable temperature (223–298 K) 31P{1H}-,NMR spectra of 1 showed a mixture of cis and trans isomers in the solution with the trans predominating at room temperature and the cis at lower temperature. Complex 1 was immobilized on silica through axial coordination of amine from 3-aminopropyltriethoxysilane functionalized silica. The immobilized materials were characterized by elemental analysis (N2), FTIR, DTA–TGA, N2-adsorption, XRD, and SEM analysis.