Heterobinuclear s‐Indacene Rhodium Complexes: Synthesis and Characterization

The monometallic complexes [Cp*M(2,6-diethyl-4,8-dimethyl-1-hydroindacenide)] [M = Fe (1), Ru (2), Co (3)] and the bimetallic species anti-[Cp*M(2,6-diethyl-4,8-dimethyl-s-indacenediide)Rh(η4-cod)] [M = Fe (4a), Ru (5a), Co (6a)] together with syn-[Cp*Ru(2,6-diethyl-4,8-dimethyl-s-indacenediide)Rh(η4-cod)] (5b) were synthesized and characterized spectroscopically and in the case of complexes 1 and 5b by X-ray diffraction. 13C and 103Rh NMR spectroscopic studies suggest that the bonding mode of the rhodium center to the s-indacenediide ligand can be described as an intermediate between η3- and η5-coordination, but closer to an η3 bonding mode when compared to indenyl–Rh complexes. This result was confirmed by the crystal structure of 5b, as evidenced by the slippage of the rhodium atom towards the periphery of the ligand. Cyclic voltammetry studies revealed intermetallic communication through the fused-ring ligand exclusively in the cases of 5a and 6a.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)