Bimetallic Carbonyl Complexes Based on Iridium and Rhodium: Useful Tools for Hydrodefluorination Reactions

Abstract

A set of bimetallic complexes based on iridium and rhodium with bis(diphenylphosphino)methane, bis(di-iso-propylphosphino)methane, diphenyl-2-pyridylphosphine and 2-(di-iso-propylphosphino)imidazole bridging ligands was prepared. The complexes were characterized by NMR and IR spectroscopy and studied quantum-chemically using DFT methods. The bimetallic systems succeeded in catalytic hydrodefluorination reactions of lower fluorinated aryl fluorides using molecular hydrogen and sodium tert-butoxide as a base. Effects of (i) ligand variation, (ii) mono- vs bimetallic nuclearity, and (iii) Ir vs Rh metal identity were studied and rationalized en route to achieve an effective hydrodefluorination.