Thermochemistry and Reactivity of Metals Engaged in Chemiionization
Abstract
The exothermicity of the chemi-ionization reaction Sm + O -> SmO+ + e has been re evaluated. Guided ion beam tandem mass spectrometry (GIBMS) has been used to determine a value for the bond dissociation energy of SmO+ of 5.73 +/- 0.07 eV, as determined by the observed reactivity of Sm+ and SmO+ with several species. Combined with the established Sm ionization energy, this value indicates an exothermicity of the chemi-ionization reaction of 0.08 +/- 0.07 eV, ~0.2 eV smaller than previous literature determinations. This value agrees well with 0.14 +/- 0.17eV, independently determined from a new measurement of the ionization energy of SmO using resonantly enhanced two-photon ionization (REMPI) and pulsed-field ionization zero kinetic energy (PFI-ZEKE) photoelectron spectroscopy, 5.7427 +/- 0.0006 eV, combined with literature bond energies of SmO. The evaluated thermochemistry also suggests that D0(SmO) = 5.83 +/- 0.07 eV, consistent with but more precise than literature values. Implications of these results for interpretation of chemical release experiments in the thermosphere were evaluated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 03, 2015
- Accession Number
- AD1000769
Entities
People
- Peter B. Armentrout
Organizations
- University of Utah