A 193 nm laser photofragmentation time-of-flight mass spectrometric study of CH sub 3 SSCH sub 3 , SSCH sub 3 , and SCH sub 3

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458295· OSTI ID:7055075

Nourbakhsh, S; Liao, C; Ng, C Y ^[1]

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1. Ames Laboratory, U. S. Department of Energy, Ames, IA (USA) Department of Chemistry, Iowa State University, Ames, IA (USA)

We have measured the time-of-flight (TOF) spectra for SCH{sub 3}, CH{sub 3}, and SSCH{sub 3} formed in the photodissociation processes, CH{sub 3}SSCH{sub 3}+{ital h}{nu}(193 nm){r arrow}2SCH{sub 3} and CH{sub 3}+SSCH{sub 3}. The dissociation energies for the CH{sub 3}S--SCH{sub 3} and CH{sub 3}SS--CH{sub 3} bonds determined at 0 K by the TOF measurements are 72.4{plus minus}1.5 and 55.0{plus minus}1.5 kcal/mol, in agreement with the literature values. The threshold value for the formation of S{sub 2} measured by the TOF spectrum for S{sub 2} is in accord with the thermochemical threshold for the process, SSCH{sub 3}+{ital h}{nu}(193 nm) {r arrow}S{sub 2}+CH{sub 3}. The threshold energy determined from the TOF spectrum for S is found to be consistent with the thermochemical threshold for the photodissociation process, SCH{sub 3}+{ital h}{nu}(193 nm) {r arrow}S({sup 1}{ital D})+CH{sub 3}, an observation supporting that S atoms are not produced in the ground S({sup 3}{ital P}) state in the 193 nm photodissociation of SCH{sub 3}. This observation is rationalized by symmetry correlation arguments applied between the S+CH{sub 3} product and SCH{sub 3} states.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 7055075
• Journal Information: Journal of Chemical Physics; (USA), Vol. 92:11; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ORGANIC SULFUR COMPOUNDS
DISSOCIATION ENERGY
PHOTOLYSIS
FAR ULTRAVIOLET RADIATION
MASS SPECTROSCOPY
TIME-OF-FLIGHT METHOD
CHEMICAL REACTIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ENERGY
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
RADIATIONS
SPECTROSCOPY
ULTRAVIOLET RADIATION
400500* - Photochemistry