Reactions of N+ ions with ethylene a theoretical study on the addition mechanism into the olefin double band

The potential energy surface of the reaction between ethylene molecules and N+ ions is investigated by using the DFT hybrid functional B3LYP with the 6-31G* basis set. The addition channel leading to the intermediate C2NH4+ is considered. We study eighteen structures of the triplet C2NH4+ cations and the transition states for their isomerizations. Then, we consider the release of a H atom to form the doublet C2NH3+ cations. To obtain more accurate values of reaction energetics and barrier heights, coupled cluster CCSD(T) calculations with the 6-311G** basis set are performed on the B3LYP/6-31G* optimized geometries. The addition of N+ into C2H4 is computed as a barrierless process leading to the triplet 1-aziridynil cation which, by ring opening, can easily evolve into the 2-azaallyl isomer. This species can then release a hydrogen atom to form the 2-azaallene cation, process that is computed to be the most likely channel.