Sequential bond energies of Pt(CO)(x)(+) (x=1-4) determined by collision-induced dissociation

The sequential bond energies of Pt(CO)(x)(+) (x = 1-4) are determined by co llision-induced dissociation with Xe using guided-ion beam tandem mass spec trometry. Analysis of the kinetic energy dependent cross sections yields 0 K bond energies in eV (kJ/mol) of 2.20 +/- 0.10 (212 +/- 10), 2.00 +/- 0.10 (193 +/- 10), 1.02 +/- 0.05 (98 +/- 5), and 0.55 +/- 0.05 (53 +/- 5) for ( CO)(x-1)Pt+-CO with x = 1-4, respectively. These values are in reasonable a greement with results of density functional ab initio calculations in the l iterature. D-0(Pt+-Xe) is determined as 0.86 +/- 0.30 eV (83 +/- 29 kJ/mol) from analysis of the ligand exchange reaction with PtCO+. The trend in the se bond energies is compared with those of nickel and sodium carbonyl catio ns and discussed in terms of sda hybridization, electrostatic interactions, and ligand-ligand steric interactions.