Synthesis and Structural Features of Rhodium Complexes of Expanded Ring N‐Heterocyclic Carbenes

Abstract

Abstract The rhodium complexes [Rh(NHC)(COD)Cl] and cis ‐[Rh(NHC)(CO) 2 Cl] of seven‐membered N‐heterocyclic carbenes (NHC) bearing aromatic N‐substituents (mesityl, xylyl and o ‐tolyl) were synthesised, and a comparison of their steric and electronic properties with those of the analogous five‐ and six‐membered NHC complexes was made on the basis of infrared and solid‐state data. The X‐ray structures for the complexes Rh(6‐Mes)(COD)Cl, Rh(7‐Mes)(COD)Cl and Rh(7‐ o Tol)(COD)Cl were determined.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)