Crystal structure of chlorido-bis-[(1,2,5,6-η)-cyclo-octa-1,5-diene]iridium(I).

The title complex, [IrCl(CH)], was synthesized directly from the reaction of IrCl·3HO with a large excess of cod (cod = cyclo-octa-1,5-diene) in alcoholic solvent. Large yellow needles were obtained by the slow cooling of a hot solution. Based on the positions of the chloride ligand and the mid-points of the four C=C bonds, the mol-ecule adopts a five-coordinate geometry that is midway between square pyramidal and trigonal bipyramidal. The material crystallizes in the ortho-rhom-bic space group with one mol-ecule per asymmetric unit in a general position and shows no significant inter-molecular inter-actions. Individual mol-ecules are aligned along [010], and these rows form a pseudo-hexa-gonal packing arrangement.