Methanol dimer - the experimental results on the {Delta}K = 1 spectrum and consistent assignments of K = 0 and K = 1

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:456917

Lovas, F J; Suenram, R D ^[1]; Stahl, W ^[2]

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1. National Institute of Standards and Technology, Gaithersburg, MD (United States)
2. Universitaet Kiel (Germany)

Previously at this meeting, the authors reported on the K = 0 spectrum of methanol dimer. In essence the theoretical model of Ohashi and Hougen indicates that 16 tunneling-rotational states should occur for each rigid rotor rotational level; 4 nondegenerate A levels, 4 fourfold degenerate G levels, and 8 doubly degenerate E levels. The internal motions which give rise to these tunneling states are: methyl internal rotation of two inequivalent tops, hydrogen bond interchange between donor and acceptor sub-units, and interchange of the lone-pair orbital of the acceptor oxygen atom. Two years ago, the authors reported observation of 15 of the expected 16 states for K{sub a} = 0 manifold and intensity measurements showed one transition in the E state appears to be a degenerate pair since it is twice the intensity of the other E state lines. Based on a two-top model for the internal rotation splittings from the two inequivalent methyl groups, the authors searched for b- and c-type transitions with {Delta}K = 1 in order to aid the assignment of the K{sub a} = 1 manifold observed previously. Three and four level connections (loops) of K = 0 and K{sub a} = 1 have been obtained for the four A states, four G states and four of the eight E states. The assignments and analysis with the two-top approach will be described.

• OSTI ID: 456917
• Report Number(s): CONF-9506113--
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTROSCOPY
DIMERS
METHANOL
ROTATIONAL STATES