Asymmetry in methyl group of ethane during internal rotation:Ab initio study
✍ Scribed by Mastryukov, Vladimir S.; Samdal, Svein
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 164 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
✦ Synopsis
Computational studies of the minimum energy pathway for internal rotation of a methyl group are often made by constraining one dihedral angle at a sequence of values and optimizing all other parameters. When this is done, the methyl group adopts an asymmetric configuration at intermediate values of the torsion angle, with unequal bond lengths, bond angles, and torsion angles, even though the moiety against which it is rotating is another methyl group. The potential surface leading to this phenomenon is investigated using Hartree᎐Fock SCF calculations at the 6-31G* and 6-311G** levels and the detailed structural behavior of the methyl group during the course of the internal rotation is examined. It is shown that the nature of the constraint governs the resulting deformation of the methyl group symmetry.