Scaled ab initio force fields of s-cis and skew conformers of methyl vinyl ether

• Published in: Journal of molecular structure 1991-06, Vol.246 (3), p.279-287
• Main Author: Ignatyev, I.S.
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Exact sciences and technology; Molecular properties and interactions with photons; Molecular spectra; Physics
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/0022-2860(91)80134-P

The ab initio 4–21G force field of the s-cis methyl vinyl ether calculated earlier was rescaled by using scale factors optimized for CH 3OCH 3 and CH 2CHF molecules. The ab initio force field in the same basis set was computed for the skew conformer and scaled by using the same factors. The theoretical shift of frequencies in going from the s-cis to the skew conformer is in keeping with observed values. Previous assignments of the observed skew form bands are revised by taking into account ab initio results. The complete optimization of geometrical parameters of the s-cis, s-trans and skew conformers was carried out in the 4–21(0*) G set and the local minimum was found at an angle of internal rotation around the CO bond equal to 149°, that is, contrary to the 4–21G optimization, close to 144° value obtained from experimental data.