Dicarbonylrhodium(I) Complexes of Bipyridine Ligands with Proximate H‐Bonding Substituents and Their Application in Methyl Acetate Carbonylation

A series of cationic cis ‐dicarbonylrhodium(I) complexes [Rh(L)(CO) 2 ]SbF 6 has been prepared containing 2,2′‐bipyridine ligands with proximate H‐bonding substituents R in the 6‐ and 6′‐position (R = OH, NH 2 , COOEt and PO(OEt) 2 ). The solid‐state structures have been determined by X‐ray crystallography for the complexes where R = OH, NH 2 and COOEt. The molecular structures have revealed metal–metal and π–π interactions between the square‐planar complexes resulting in the formation of molecular chains in the solid state. IR studies on the reaction of [Rh(bipy)(CO) 2 ]SbF 6 with MeI have shown the formation of a neutral complex [RhI(CO)(bipy)], which undergoes oxidative addition of MeI much faster than the cationic complex [Rh(bipy)(CO) 2 ] + . Although all complexes show good activities for the carbonylation of methyl acetate, this is believed to be due to their instability and the formation of [RhI 2 (CO) 2 ] – under the reaction conditions.