Photoionization mass spectrometry of CH/sub 3/SH, CD/sub 3/SH, and CH/sub 3/SD: Heats of formation ofCH/sub 3/S/sup +/(CH/sub 2/SH/sup +/), CH/sub 2/S/sup +/, CH/sub 2/S, and HCS/sup +/

Journal Article · Wed Dec 01 00:00:00 EST 1982 · J. Chem. Phys.; (United States)

OSTI ID:6715951

Kutina, R E; Edwards, A K; Goodman, G L; Berkowitz, J

Photoionization yield curves have been obtained for the major ions from CH/sub 3/SH. Auxiliary studies with selectively deuterated species reveal that CD/sub 3/S/sup +/ has a slightly lower threshold than CD/sub 2/SH/sup +/ from CD/sub 3/SH; but CH/sub 2/SD/sup +/ has a lower threshold than CH/sub 3/S/sup +/ from CH/sub 3/SD. An analysis of alternative interpretations is presented. The isotopic studies also imply that CH/sub 2/S/sup +/ is more stable than HCSH/sup +/, and HCS/sup +/ is more stable than CSH/sup +/. The value ..delta..H/sup 0//sub f/,0(HCS/sup +/)< or =259.2 +- 0.9 kcal/mol obtained in this study is in good agreement with a bracketed proton affinity for CS, but differs significantly from a recent ab initio calculation. This result confirms the view that HCS/sup +/ can be formed in interstellar clouds by exothermic reactions. The reaction CH/sub 3/S/sup +//CH/sub 2/SH/sup +/..-->..HCS/sup +/+H/sub 2/ proceeds weakly at threshold, and much more strongly after overcoming an activation barrier of approx.0.9 eV.

• Research Organization: Argonne National Laboratory, Argonne, Illinois 60439
• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 6715951
• Journal Information: J. Chem. Phys.; (United States), Vol. 77:11
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ORGANIC SULFUR COMPOUNDS
FORMATION HEAT
MASS SPECTROSCOPY
PHOTOIONIZATION
MOLECULAR IONS
THERMODYNAMIC PROPERTIES
CHARGED PARTICLES
ENTHALPY
IONIZATION
IONS
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
REACTION HEAT
SPECTROSCOPY
640302* - Atomic
Molecular &amp; Chemical Physics- Atomic &amp; Molecular Properties &amp; Theory