Abstract
Ab initio (6-31G* and MP3/6-31G*//6-31G*) calculations show that vinyl cations substituted with α-CN, α-CHO and α-CF
3 groups are by 15–18 kcal/mol less stable than their saturated analogues and are among the least stable carbenium ions generated to date via solvolysis.
Theoretical calculations up to the MP3/6-31G*//6-31G* level have been used to delineate the destabilization of cations
1 and
2 by electron-withdrawing groups (EWG: Cl, F, CN, CHO and CF
3).