Stimulated emission pumping spectroscopy of CH[sub 3]O ([ital [tilde X]] [sup 2][ital E], [nu][sub 6]): New observations on the Jahn--Teller effect

Journal Article · Mon Mar 01 00:00:00 EST 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465036· OSTI ID:7014282

Geers, A; Kappert, J; Temps, F ^[1]; Sears, T J ^[2]

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1. Max-Planck-Institut fuer Stroemungsforschung, Bunsenstrasse 10, 3400 Goettingen (Germany)
2. Brookhaven National Laboratory, Upton, New York 11973 (United States)

Experiments have been carried out using hot band laser induced fluorescence (LIF) excitation and stimulated emission pumping (SEP) spectroscopy to characterize the excited doubly degenerate [nu][sub 6] vibrational mode of CH[sub 3]O ([ital [tilde X]] [sup 2][ital E]) which is of interest with respect to the Jahn--Teller effect in the molecule. Rotationally resolved spectra were recorded for the [ital [tilde A]] [sup 2][ital A][sub 1][leftrightarrow][ital [tilde X]] [sup 2][ital E], 6[sub 1][sup 0] and 3[sub 1][sup 0]6[sub 1][sup 0] bands. The observed line structures indicate that these bands must be assigned to [Delta][ital j]=3/2 parallel ([Delta][ital K]=0) vibronic bands. No evidence could yet be obtained for the corresponding [Delta][ital j]=1/2 vibronic transitions assumed previously. The results imply that the linear Jahn--Teller effect for [nu][sub 6] is very small. Instead, coupling between the [ital [tilde A]] [sup 2][ital A][sub 1] and the [ital [tilde X]] [sup 2][ital E] states by a pseudo-Jahn--Teller interaction operator is suggested as a plausible mechanism for the observation of the forbidden transitions.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7014282
• Journal Information: Journal of Chemical Physics; (United States), Vol. 98:5; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
METHYL RADICALS
FORBIDDEN TRANSITIONS
VIBRATIONAL STATES
ORGANIC OXYGEN COMPOUNDS
FLUORESCENCE
JAHN-TELLER EFFECT
LASER SPECTROSCOPY
OPTICAL PUMPING
RESOLUTION
ROTATIONAL STATES
SPECTROSCOPY
STIMULATED EMISSION
ALKYL RADICALS
EMISSION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
LUMINESCENCE
ORGANIC COMPOUNDS
PUMPING
RADICALS
664200* - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)