Rhodium carbonyl complexes featuring carbodiphosphorane-based pincer ligands

Abstract

The coordination of a pincer ligand with a protonated carbodiphosphorane (CDP) as central donor group, [(dppm)2CH]+ (1), in the rhodium(I) complex [({dppm}2CH)RhCl(CO)]+ (2) is reported (dppm = 1,1-bis(diphenylphosphino)methane). In contrast to related iridium(I) precursors, no C-H-oxidative addition is observed with [RhCl(CO)2]2 in this reaction. The different reactivity of rhodium(I) and iridium(I) precursors is investigated by means of density functional theory (DFT). Finally, the CDP-based pincer-type complex [({dppm}2C)Rh(CO)]+ (3) was obtained by deprotonation of complex 2.