Guided Ion Beam Studies of the Dy + O → DyO + e Chemi-ionization Reaction Thermochemistry and Dysprosium Oxide, Carbide, Sulfide, Dioxide, and Sulfoxide Cation Bond Energies.

Guided ion beam tandem mass spectrometry (GIBMS) was used to measure the kinetic energy dependent product ion cross sections for reactions of the lanthanide metal dysprosium cation (Dy) with O, SO, and CO and reactions of DyO with CO, O, and Xe. DyO is formed through an exothermic process when Dy reacts with O, whereas all other processes observed are found to be endothermic. The kinetic energy dependences of these cross sections were analyzed to yield 0 K bond dissociation energies (BDEs) for DyO, DyC, DyS, DyO, and DySO. The 0 K BDE for DyO is determined to be 5.60 ± 0.02 eV from the weighted average of six independent thresholds, which are dominated by the slightly endothermic reaction of Dy with SO. Combined with the well-established Dy ionization energy (IE), this value indicates that the chemi-ionization reaction, Dy + O → DyO + e, is endothermic by 0.33 ± 0.02 eV. Theoretical BDEs for Dy-O, Dy-C, Dy-S, ODy-O, and Dy-SO were calculated at several levels of theory and basis sets for comparison with experiment with reasonable agreement achieved.