Heterobimetallic Iron-Rhodium Complexes. Synthesis and Characteristics of CpFe(mu-eta5:eta5-as-indacenediide)RhL2 (L2 = COD, NBD, (ethylene)2)

The heterobimetallic CpFe(eta5:eta5-as-indacenediide)RhL2 complexes (L2 = COD (2), NBD (3), (ethylene)2 (4)) have been obtained from metalation of the mononuclear lithium CpFe-(eta5-as-indacenediide) with [Rh(mu-Cl)L2]2. Mixtures of syn and anti heterobimetallic complexes were formed and fully characterized by 2D NMR spectroscopy. The reactivity at the rhodium center is greatly influenced by the presence of the ferrocenyl moiety. The voltammetric behavior and the optical spectra are in favor of the existence of significant electronic interactions between the two metals.