J. Electron Spectrosc. (1999)
Photofragmentation
of OCS at the S 1s edge
John J. Neville, Tolek Tyliszczak
and Adam P. Hitchcock
Department of Chemistry, McMaster
University, Hamilton, ON, Canada L8S 4M1
Abstract. The photofragmentation
of carbonyl sulphide following sulphur Is excitation has been investigated
using monochromated synchrotron radiation and ion time-of-flight mass spectroscopy.
Photoion branching ratios indicate that fragmentation to atomic ions increases
at the onset of S 1s excitation and that the yield of multiply charged
ions increases at the onset of S 1s excitation and again at the S 1s ionization
threshold. Cleavage of the carbon-sulphur bond is favoured over cleavage
of the oxygen-carbon bond both above and below the sulphur ls ionization
threshold. The multi-coincident detection of up to three photoions per
ionization event is used to identify the fragmentation channels following
S 1s®
p * excitation
and explore the fragmentation dynamics.