Abstract
The barriers for conformational exchange processes in pentaethylbenzenes C6Et5R (R = H, Br, COCH3, OCOCH3 and OCOPh) were determined by NMR lineshape analysis; for the latter three substances these processes include both the stepwise rotation of the ethyl groups and the 180°reorientation of the side-chain R. The experimental barriers were compared to those calculated by molecular mechanics (MM3). These results have implications in the long- standing argument about the barrier of ethyl group rotation in hexaethylbenzene (R = Et) and some of its metal complexes.
Original language | English |
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Pages (from-to) | 4003-4014 |
Number of pages | 12 |
Journal | Tetrahedron |
Volume | 55 |
Issue number | 13 |
DOIs | |
State | Published - 26 Mar 1999 |
Keywords
- Benzenes
- Conformation
- Molecular mechanics
- NMR