Rotational spectrum of the Ar–dimethyl sulfide complex

Yoshio Tatamitani, Akinori Sato, Yoshiyuki Kawashima, Nobukimi Ohashi, James M. LoBue, Eizi Hirota

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

The rotational spectra of three isotopomers of the Ar-dimethyl sulfide (DMS) complex - normal, 34S, and 13C species - were measured in the frequency region from 3.7 up to 24.1 GHz by Fourier transform microwave spectroscopy. The normal species yielded 43 a-type and 79 c-type transitions. No Ar tunneling splitting was observed, while many transitions were split by the internal rotation of the two methyl tops of the DMS unit. In cases where the K-type splitting was close to that due to methyl internal-rotation, several forbidden transitions were observed that followed b-type selection rules. All of the observed transition frequencies were analyzed simultaneously using a phenomenological Hamiltonian also used in previously published work describing the Ar-dimethyl ether (DME) and Ne-DME complexes. The rotational and centrifugal distortion constants and the potential barrier height to methyl-top internal rotation, V3, were determined. The rotational constants were consistent with an Ar-DMS center of mass (cm) distance of 3.796 (3) Å and a S-cm-Ar angle of 104.8 (2)°. The V3 potential barrier obtained, 736.17 (32) cm-1, was 97.8% of the DMS monomer barrier. By assuming a Lennard-Jones-type potential, the dissociation energy was estimated to be 2.4 kJ mol-1, which was close to the value for Ar-DME, 2.5 kJ mol-1.

Original languageAmerican English
JournalJournal of Molecular Spectroscopy
Volume257
DOIs
StatePublished - Jan 1 2009

Keywords

  • Ar–(CH3)2S complex
  • Fourier transform microwave spectrum
  • Internal rotation
  • Molecular structure
  • Van der Waals complex

DC Disciplines

  • Chemistry

Fingerprint

Dive into the research topics of 'Rotational spectrum of the Ar–dimethyl sulfide complex'. Together they form a unique fingerprint.

Cite this