ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
In the fluorescence excitation spectrum of acetaldehyde cooled in a supersonic jet, we performed a full rotational analysis of combination bands 10011400+150n and 10011400−150n, n=0–4 in the system A˜1A″–X˜1A′. The vibrational frequency of the C–C–O bending mode is determined to be ν10′=373.163(3) cm−1. The rotational structures of combination bands 10011400+1502, 10011400−1502, 10011400+1503, and 10011400−1504 resemble the structures of 1400+1502, 1400−1502, 1400+1503, and 1400−1504, respectively, but the intense E lines observed for 1400−1503 are not found in 10011400−1503. Torsional spacings observed in the C–C–O bend series are slightly smaller than those in the pure torsional series 140+ and 140−; these result from a decreased torsional barrier due to the C–C–O bending motion. Inversion spacings exhibit a pattern similar to those in the series 140+ and 140−. Reversed abnormal torsional sublevel A/E splittings are found for states n=0–2 of the 101140− series, similar to those in the 140− series. For states n=3, the K rotational structures between the 140+ and 101140+ series and for n=4, the 140− and 101140− series are more similar than those between the pure torsion-inversion series 140+ and 140−. Hence, these experimental data imply that the interaction of the C–C–O bend with rotational structures of torsional states is smaller than that resulting from the aldehyde inversion. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1424312
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