Reactions of N+ ions with benzene: a theoretical study on the C6NH6+ potential energy surface

The nitrenium ions of formula C6NH6+ arising from the reaction between benzene molecules and atomic nitrogen ions, N+(3P), are investigated by means of theoretical methods so that their structures and relative stabilities are calculated. Our study is carried out by utilizing the DFT hybrid functional B3LYP in conjunction with the split valence 6-31G* basis set. Both the triplet and the singlet state C6NH6+ cations are considered. The electron deficient N+ ions attack the π electron density of benzene and yield the cation labelled T1 in which the nitrogen interacts with the edge of benzene. This addition is exothermic by 7.69 eV and barrierless. From T1, the insertion of N+ into the benzene CC bond gives the triplet azepine nitrenium cation, T5, whilst its insertion into the CH bond yields the triplet phenylnitrenium cation, T6, via the intermediate T3. However, further C6NH6+ structures and isomerization pathways are investigated in order to obtain a comprehensive analysis of the potential energy surface under study