Theoretical characterization of the intrinsic barrier for cationic SN2 methyl transfer between oxygen centers
✍ Scribed by Z.D. Hamou-Tahra; E. Kassab; M. Allavena; E.M. Evleth
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- English
- Weight
- 482 KB
- Volume
- 150
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
The ion-molecule surface for the interaction of water with protonated methanol is theoretically characterized using both ab initio and semi-empirical methods. The SN2 transition state of the water exchange reaction ( H20--CH3--OH2)+, is determined.
We estimate the intrinsic barrier for cationic methyl transfer between two oxygen centers to be about 9 kcal/mol, less than half the value found in comparative anionic transfers. Marcus theory is used to estimate the energy of the critical transition state in the gas-phase reaction of protonated methanol with methanol to give protonated dimethyl ether and water.