Paramagnetic intermediates in oxidative coupling reactions. Molecular orbital calculations as an aid to rational organometallic synthesis

Oxidation of (η5-C5H5)Rh(PPh3)2 by silver ion results in coupling of cyclopentadienyl ligands to give fulvalene–dirhodium(II) complexes; semi-empirical MO calculation give insight into the reaction sequence and allow a rational extension to the coupling reaction of a co-ordinated allyl ligand to give a hexa-1,5-diene complex.