Activation of O2, CO, and CO2 by Pt+:: The thermochemistry of PtO+

Reactions of Pt+ with O-2, CO, and CO2 have been studied as a function of kinetic energy using guided ion beam tandem mass spectrometry in order to elucidate the bond energy of the PtO+ product. To further characterize the reaction Of Pt+ With CO2, the reverse reaction of PtO+ with CO, and the collision-induced dissociation Of PtCO2+ with Xe and Ar are also studied. In all cases, the kinetic energy dependences for these reactions show endothermic behavior except for PtO+ CO --> Pt+ + CO2 and PtCO2+ + Xe --> PtXe+ + CO2. Analyses of the endothermic reaction cross sections yield the 0 K bond dissociation energies (BDEs) in eV (kJ/mol) of D-0(Pt+-O) = 3.26 +/- 0.07 (315 +/- 7), D-0(Pt+-CO) = 2.28 +/- 0.05 (220 +/- 5), D-0(Pt+-CO2) - 0.62 +/- 0.05 (60 +/- 5), and D-0(Pt+-C) = 5.46 +/- 0.05 (527 +/- 5), reasonably consistent with available theoretical values. Combining the PtO+ BIDE measured here with literature data also yields the ionization energy of PtO as 9.52 +/- 0.25 eV. These data, along with ab initio calculations at the B3LYP/6-311 +G(3df) level, enable the potential energy surfaces for the activation of CO, by Pt+ to be mapped out in some detail. Evidence that PtCO2+ has stable forms of both O-Pt+-CO and Pt+.CO2 are presented.