[1,3-bis(2-ethoxyphenyl)imidazolidin-2-ylidene]bromo(cycloocta-1,5-diene)rhodium(I)

Abstract

The title complex, [RhBr(C8H12)(C19H22N2O2)], has a distorted square-planar geometry. There are two molecules, A and B, in the asymmetric unit. The Rh-C bond distance between the N-heterocyclic ligand and the metal atom is 2.039 (2) angstrom in molecule A and 2.042 (2) angstrom in molecule B. The angle between the carbene heterocycle and the coordination plane is 87.56 (12)degrees in molecule A and 87.03 (11)degrees in molecule B. It is shown that the average Rh-C(COD) (COD is cyclooctadiene) distance is linearly dependent on the Rh-(imidazolidine)distance in this type of compound. This can be ascribed to the steric hindrance produced by the packing. The crystal structure contains intramolecular C-H center dot center dot center dot O and intermolecular C-H center dot center dot center dot Br interactions.