106223-27-2Relevant academic research and scientific papers
Reduction-Oxidation Properties of Organotransition-metal Complexes. Part 23. Pentaphenylcyclopentadienyl Carbonyl Complexes of Cobalt and Rhodiu
Conelly, Neil G.,Raven, Stephen J.
, p. 1613 - 1618 (2007/10/02)
The reaction of or 2> with C5Ph5Br and zinc dust in tetrahydrofuran (thf) gives (1,M=Co or Rh); in the case of rhodium, the intermediate is isolable if the reaction is carried out in benzene.In the presence of +, (1,M=Rh) undergoes oxidatively-induced carbonyl substitution with ligands, L; for L=P(OPh)3, the formation of is catalytic in the oxidant.The complexes (2) are also prepared via (a) the substitution of with PPh3 or AsPh3 and subsequent reduction by , (b) reduction of (3,M=Co) in the presence of P(OMe)3 or P(OPh)3, or (c) reduction of (η-C5Ph5)> (5) in the presence of CO.Complexes (3,M=Co or Rh) are prepared from (1) and iodine in toluene-hexane at 0 deg C; the rhodium complex (3,M=Rh) is reduced by to give 2>.Compound (5) results from the addition of P(OMe)3 to 2> (4), which is the product of the reaction between (1,M=Rh) and bromine in CH2Cl2.The compounds (2) undergo two one-electron oxidations at a platinium electrode in CH2Cl2; the first is reversible and the second is irreversible.The monocations have been characterised in solution by i.r. and e.s.r. spectroscopy.Low-temperature e.s.r. spectroscopy has shown that the radical cation + is stable at -196 deg C.
