Ion Molecule Reactions of Rollover Cyclometalated [Pt(bipy-H)](+) (bipy=2,2 '-bipyridine) with Dimethyl Ether in Comparison with Dimethyl Sulfide: An Experimental/Computational Study

The ion molecule reactions of dimethyl ether with cyclometalated [Pt(bipy-H)](+) were investigated in gas-phase experiments, complemented by DFT methods, and compared with the previously reported ion molecule reactions with its sulfur analogue. The initial step corresponds in both cases to a platinum-mediated transfer of a hydrogen atom from the ether to the (bipy-H) ligand, and three-membered oxygen- and sulfur-containing metallacycles serve as key intermediates. Oxidative C C bond coupling (dehydrosulfurization), which dominates the gas-phase ion chemistry of the [Pt(bipy H)](+) ion with dimethyl sulfide, is practically absent for dimethyl ether. The competition in the formation of C2H4 and CH2X (X=O, S) in the reactions of [Pt(bipy H)] + with (CH3)(2)X (X=O, S) as well as the extensive HID exchange observed in the [Pt(bipy-H)](+)/(CH3)(2)O system are explained in terms of the corresponding potential-energy surfaces.