GAS-PHASE RATES OF ALKANE C-H OXIDATIVE ADDITION TO A TRANSIENT CPRH(CO) COMPLEX

The gas-phase irradiation of CpRh(CO)2 (Cp = eta-5-C5H5) was examined in order to study the rates of reaction of the 16-electron intermediates presumed to bc involved in the C-H oxidative addition of alkanes. "Naked" (unsolvated) CpRh(CO) was detected, and direct measurements of the rates of reaction of this very short-lived complex with alkane C-H bonds were made. Activation of C-H bonds occurs on almost every collision for alkanes of moderate size, and intermediates in which the alkanes are bound to the metal centers, without their C-H bonds being fully broken, are implicated as intermediates in the overall reaction.