Diminished cage effect in solid p-H2: Infrared absorption of CH3 S observed from photolysis in situ of CH3 SH, CH 3 SCH3, or CH3 SSCH3 isolated in p-H2 matrices

Mohammed Bahou, Yuan-Pern Lee*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


We report the infrared absorption spectrum of the methylthio (or thiomethoxy) radical, CH3 S (X E2 3/2), produced via photodissociation in situ of three precursors CH3 SH, CH3 SCH3, and CH3 SSCH3 isolated in solid p -H 2. The common absorption features observed with similar intensity ratios in each experiment are assigned to CH3 S. The wavenumbers of these features agree satisfactorily with those predicted with a spin-vibronic Hamiltonian accounting for the anharmonic effects and the Jahn-Teller effects to the quartic term [A. V. Marenich and J. E. Boggs, J. Chem. Theory Comput. 1, 1162 (2005)]. In addition to an absorption line at 724.2 cm-1, corresponding to a transition of 31 previously determined to be 727 cm -1 from fluorescence spectra of gaseous CH3 S, we identified fundamental transitions 61 (a1) at 771.1, 61 (e) at 1056.6, 51 (a1) at 1400.0, 41 (a1) at 2898.4 cm -1, and several combination and overtone transitions. In contrast, photolysis of CH3 SSCH3 isolated in solid Ar produces mainly H2 CS, CH3 SH, and CS2, but no CH 3 S. These results demonstrate the feasibility of using photolysis in situ of precursors isolated in solid p -H2 to produce free radicals by taking advantage of the diminished cage effect of the matrix.

Original languageEnglish
Article number164316
JournalJournal of Chemical Physics
Issue number16
StatePublished - 28 Oct 2010

Fingerprint Dive into the research topics of 'Diminished cage effect in solid p-H<sub>2</sub>: Infrared absorption of CH<sub>3</sub> S observed from photolysis in situ of CH<sub>3</sub> SH, CH <sub>3</sub> SCH<sub>3</sub>, or CH<sub>3</sub> SSCH<sub>3</sub> isolated in p-H<sub>2</sub> matrices'. Together they form a unique fingerprint.

Cite this