A study of the chemiionization reactions of Ca, Sr and Ba with O2(X 3Σ-g)
Date
1994Source Title
Chemical Physics
Print ISSN
0301-0104
Volume
179
Issue
3
Pages
455 - 462
Language
English
Type
ArticleItem Usage Stats
234
views
views
254
downloads
downloads
Abstract
Chemielectron and chemiion spectra resulting from the reactions of effusive beams of Ca, and Sr and Ba (in their ground 1S states) with ground state molecular oxygen O2(X 3Σ- g) have been recorded using electron spectroscopy and mass spectrometry. The chemielectron spectra are similar for all three reactions exhibiting a strong near-zero energy band and another band at higher electron energies. The chemiion spectra show O+ 2, M+ and M2O+ 2 as the major ions. The total ion current as well as the individual ion intensities, have been recorded as a function of the extraction potential on the reaction cell. The results obtained indicate that the metal oxide dimer ion is the primary chemiion, formed via an associative ionization reaction of a metal atom with a long-lived metal superoxide intermediate MO*2. A two state potential energy curve model is proposed for the M+MO*2 reaction to explain the shape of the experimental electron distribution. © 1994.