Platinum-mediated coupling of methane and small nucleophiles (H2O, PH3, H2S, CH3NH2) as a model for C-N, C-O, C-P, and C-S bond formation in the gas phase

The reactions of Pt+ and PtCH2+ with the nucleophiles H2O, PH3, H2S, HCl, CH3NH2, and CH3OH are studied by Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometry. In the reactions of PtCH2+, carbon-heteroatom bond formation can be accomplished for all substrates except CH3OH and HCl. The reaction of PtCH2+ with two molecules of water yields Pt(CO)(H2O)(+) and constitutes a gas-phase model for the platinum-mediated generation of water gas according to CH4 + H2O - CO + 3H(2). In the reactions with PH3 and H2S, carbon-phosphorus and carbon-sulfur bond formation to PtCPH+ and PtCS+ competes with demethanation and dehydrogenation of the substrates to yield PtSn+ (n = 1-4) and PtPnHm+ (n = 1-6; m = 0-3) compounds, respectively. For organic nucleophiles such as CH3NH2 and CH3OH, C-N and C-O coupling is much less efficient than platinum-mediated C-H bond activation of the substrates.