Electronic structure of phenyl cation by MC SCF ab initio calculations

Abstract

In order to investigate the mechanistic aspects of gas-phase ion-molecule reactions of phenyl cation, C 6H 5 +, formed by nuclear decay of tritiated benzene, with nucleophilic species, the electronic structure of this ion has been examined by ab initio methods. In particular, SCF and MC SCF calculations have been performed on the two most stable electronic states of phenyl cation, 1A 1 and 3B 1. The results obtained indicate that 1A 1 is the ground electronic state, 3B 1 being ≈ 5 (15) kcal mol −1 higher in the 6-31G*//STO-3G (4-31G//STO-3G) MC SCF level of calculation.