Two-dimensional treatment of the aldehydic carbonyl torsion and hydrogen wagging in gas-phase propanal
✍ Scribed by A. Vivier-Bunge; V. H. Uc; Y. G. Smeyers
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 226 KB
- Volume
- 72
- Category
- Article
- ISSN
- 0020-7608
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✦ Synopsis
The potential energy surface for the simultaneous aldehydic carbonyl torsion and hydrogen wagging in propanal has been determined at RHFrMP2 level Ž . using the 6-311G 3df, p basis set. Sixty-three energy values were fitted to an analytic form of C symmetry. With this potential, as well as with the kinetic parameters and the S Ž . electric dipole moment variations, the far infrared FIR frequencies and intensities for the aldehydic carbonyl torsion and hydrogen wagging were determined theoretically. It is found that the two-dimensional calculation for the cis conformer satisfactorily reproduces not only the asymmetric aldehyde torsion spectrum, but yields also a torsionally excited progression for the aldehydic hydrogen wagging modes. Finally, the introduction of the aldehydic hydrogen wagging mode in the calculations is seen to enhance significantly the intensities the carbonyl torsion bands.