Reaction of Sc+, Ti+, and V+ with CO. MC+ and MO+ bond energies

Abstract

The reactions of Sc+, Ti+, and V+ with CO are studied as a function of translational energy in a guided-ion-beam tandem mass spectrometer. Formation of both metal-carbide and metal-oxide ions are observed and rationalized by a direct atom abstraction mechanism. At high energies, the ScC+ and ScO+ cross sections exhibit additional features that are unusual but can be explained by an impulsive pairwise mechanism and formation of excited-state product ions, respectively. Thresholds of the reaction cross sections are interpreted to give the O K bond energies (in eV) D0(ScC+) = 3.34 ± 0.06, D 0(TiC+) = 4.05 ± 0.24, D0(VC +) = 3.87 ± 0.14, D0(ScO+) = 7.11 ± 0.08, D0(TiO+) = 6.88 ± 0.07, and D 0(VO+) = 5.81 ± 0.17. Additional studies are used to help verify the bond energy for ScO+ and yield a recommended value of 7.14 ± 0.11 eV. The nature of the bonding in MO+ and MC+ is discussed and compared for these three metal ions. © 1991 American Institute of Physics.