Dynamic NMR study of trans-cyclodecene
- Jackson State Univ., MS (United States)
The slow-exchange {sup 13}C spectrum of trans-cyclodecene at -154.9{degree}C shows eight peaks of the olefinic carbons, and these are interpreted in terms of five conformations. Three of the conformations are of C{sub 1} symmetry, and two are of C{sub 2} symmetry. Further evidence for the number of conformations and their symmetries came from a proton NMR spectrum of the olefinic hydrogens taken at -154.9{degree}C with decoupling the allylic hydrogens. Populations ranged from 3.0% to 37.6% with the least-populated conformation having a free energy of 0.59 kcal/mol, relative to the most stable conformer. The conformations studied by Saunders and Jimenez-Vazquez using Allinger`s MM3 force field are described, and the calculated strain energies and populations are discussed. Energies for six conformations were also obtained from ab initio calculations at the HF/6-311G{sup *} level. 22 refs., 4 figs., 3 tabs.
- DOE Contract Number:
- FG05-86ER75274
- OSTI ID:
- 437412
- Journal Information:
- Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 50 Vol. 118; ISSN JACSAT; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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