ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The kinetic energy releases of the photodissociation processes, CH3SH+hν (193 nm)→CH3+SH, CH3S+H, and CH2S+H2, have been measured using the time-of-flight mass spectrometric method. These measurements allow the direct determination of the dissociation energies for the CH3–SH and CH3S–H bonds at 0 K as 72.4±1.5 and 90±2 kcal/mol, respectively. The further dissociation of SH according to the process SH+hν (193 nm)→S+H has also been observed. The appearance energy (AE) of S produced in the latter process is consistent with the formation of S(3P)+H. The photoelectron–photoion coincidence (PEPICO) spectra for CH3SH+, CH3S+ (or CH2SH+), and CH2S+ from CH3SH have been measured in the wavelength range of 925–1460 A(ring). The PEPICO measurements make possible the construction of the breakdown diagram for the unimolecular decomposition of internal-energy-selected CH3SH+ in the range of 0–83 kcal/mol. The AE measured for CH2S+ is consistent with the conclusion that the activation energy is negligible for 1,2-H2 elimination from CH3SH+.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.461103
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