Crystal structure of di-µ-carbonyl-nonacarbonyl-(π-cyclopentadienyl-rhodio)tri-iron(3Rh–Fe)(3Fe–Fe), (π-C5H5)RhFe3(CO)11

Abstract

The crystal and molecular structure of the title compound has been elucidated. The compound crystallizes in the centrosymmetric monoclinic space group P2₁/n(C_2h⁵, No. 14) with a= 12·298(9), b= 11·928(15), c= 13·341(17)Å, β= 95·9 (0·1)° and Z= 4. The structure was solved by a full three-dimensional X-ray diffraction study, using counter data and all non-hydrogen atoms were located. The structure has been refined by least-squares techniques to R 6·98% for 1227 independent non-zero reflections. To a first approximation the molecule consists of three Fe(CO)₃ groups and a (π-C₅H₅)Rh moiety which are mutually connected via metal–metal bonds [Fe–Fe 2·553(3)–2·594(3) and Fe–Rh 2·568(3)–2·615(3)Å] along with two bridging [Rh–(CO)–Fe] carbonyl groups. However, crowding of ligands around the surface of the tetrahedral metal cluster results in further metal–carbonyl contacts which appear to be of a bonding nature.