Approximate Selection Rules for |K| = 1–0 and 1–1 Tunneling–Rotation Transitions in the Methanol Dimer

✍ Scribed by Nobukimi Ohashi; Jon T. Hougen

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 129 KB
• Volume: 203
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2000.8153

✦ Synopsis

Approximate K ϭ 0 and ͉K͉ ϭ 1 tunneling-rotation eigenfunctions for the four A, four E, and one G symmetry species present in the methanol dimer, derived from molecular parameters obtained previously from a least-squares fit to transition frequencies involving K ϭ 0 and 1 levels, are used to clarify some apparent contradictions associated with traditional b-and c-type transition designations in the E and G tunneling-rotational states of this dimer. These approximate eigenfunctions also predict strong and weak line intensities which are consistent with the pattern of strong a-, b-, and c-type transitions observed, thus supporting our previous separate K-state analysis based only on energy level differences. Some of the predicted weaker ͉K͉ ϭ 1 a-type transitions should be experimentally observable with more signal averaging.