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

Abstract

Theoretical studies of the transition metal-carbonyl systems MCO and M(CO)2, M=Ti, Sc, and VThe 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 metaloxide 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 0 K bond energies (in eV) DO(ScC+) = 3.34 ± 0.06, DO(TiC+) = 4.05 ± 0.24, DO(VC+) = 3.87 ± 0.14, DO(ScO+) = 7.11 ± 0.08, DO(TiO+) = 6.88 ± 0.07, and D o(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 e V. The nature of the bonding in MO + and MC + is discussed and compared for these three metal ions.

Ionization potentials and bond energies of TiO, ZrO, NbO and MoO

“…As can be seen, the agreement is excellent if the D 0 ͑TiO ϩ )ϭ6.88(7) of Clemmer et al 11 is used, confirming that measurements of D 0 (MO ϩ ) by guided beam mass spectrometry are very reliable and are probably better than the literature data on the neutral's bond energies for all metal oxides. For MoO ϩ there exists an independent determination of the bond energy by Kretzschmar et al 58 using the ion/molecule reaction bracketing technique.…”

“…11,12 Measurement of the dependence of the reaction cross sections of the M ϩ ϩO 2 and M ϩ ϩCO reaction on the ions' kinetic energy yielded the bond energies at 0 K by extrapolation ͑Table V͒. Errors in these types of measurements can be introduced through different sources.…”

“…11,12 In their studies, guided metal-ion beam reactions with CO and O 2 were used to produce YO ϩ , ZrO ϩ , NbO ϩ and MoO ϩ . From analyses of the kinetic energy dependence of the reaction cross section, the bond dissociation energies at 0 K of the molecule MO ϩ ͑M ϭ Y, Zr, Nb, and Mo͒ were obtained.…”

Intramolecular Ion-Molecule Reactions within Ti+(CH3COCH3)nHeteroclusters: Oxidation Pathway via C=O Bond Activation

“…32 The initial interaction site between the Ti + and CH3 COCH 3 molecules within the heterocluster was envisioned to be the more basic site of the oxygen atom. The bonding in the association complex has been found to involve the formation of a dative bond requiring electron donation from the CH3COCH3 molecule to the 3d orbital of the Ti + ion.…”

Electronic Spectroscopy of Diatomic VC

“…Similarly, bond energies of the cations ScC + , 50 TiC + , 50 VC + , 50,51 CoC + , 52 YC + , 53 ZrC + , 53 NbC + , 53 MoC + , 53 RuC + , 54 RhC + , 55 HfC + , 56 TaC + , 56 WC + , 56 ReC + , 57 IrC + , 58 and PtC +59,60 have been measured using guided ion beam mass spectrometry. Bond energies have also been measured for CrC + , 61 FeC + , 62 CoC + , 62 NbC + , 63 MoC + , 61 and WC +61 by photofragmentation threshold measurements.…”