THE STABLE RADICAL-CATION [MO-2(MU-C(8)ME(8))(ETA-C5H5)(2)](- AN INTERMEDIATE IN THE REDOX ACTIVATION OF AN ALKYL C-H BOND AND A PROBE OF METAL-ALKENE BONDING() )

An X-ray structure determination has shown;that oxidation of [Mo-2(mu- C(8)Me(8))(eta-C5H5)(2)] 1 to [Mo-2(mu-C(8)Me(8))(eta-C5H5)(2)](+)1(+) results in geometric changes consistent with the presence of a three- electron metal-alkene interaction; cation 1(+) undergoes:both H-atom a bstraction (with the CPh(3) radical) and oxidative deprotonation {on a ddition of [Fe(eta-C5H5)2](+)} to give [Mo-2(mu-C(8)Me(7)CH(2))(eta-C5 H5)(2)](+)2(+) showing that the mechanism of the redox-activation of o ne C-H bond of 1 (EC or EEC) is critically dependent on the nature of the chemical oxidant.