Crystal and Molecular Structures of the Organometallic Species [Rh2(bim)2(cod)2]Cl2 ·2H2O [bim = bis-(1-imidazolyl)methane; cod = 1,5-cyclooctadiene]

The synthesis and X-ray powder diffraction data for the organometallic [Rh2(bim)2(cod)2]Cl2·2H2O species are reported. Its crystal and molecular structures were determined by simulated annealing and full-profile Rietveld refinement methods. [Rh2(bim)2(cod)2]Cl2·2H2O was found to crystallize in the orthorhombic Cmca space group. The lattice parameters were determined to be a =21.3574(6), b=10.7764(3), c=14.2795(4) Å, V=3286.5(2) Å3, for Z=4. The crystal structure was found to contain dimeric [Rh2(bim)2(cod)2]2+ cations, in which the bim ligands bridge Rh(cod) fragments with an intermetallic separation of ca. 8.90 Å. The crystal structure is completed by chloride ions and hydrogen-bonded water molecules, situated in the small cavities of the large cation substructure. The conformation of the bim ligand, lying on a crystallographic mirror plane, is rigorously Cs.