DFT Modeling of Chemical Interactions of the Ethylene Molecule with Nitrogen Oxides

Abstract The quantum chemistry calculations of the systems “ethylene – nitrogen oxides (NO x )” were conducted using electron density functional method B3LYP/6-31G** with correlation-consistent cc-pVTZ basis set and pure non-empirical second-order Moeller–Plesset (MP2) perturbation theory approach with the same basis set in order to estimate the possibilities of the chemical interactions between the components in gas phase and low temperature co-condensates and to reveal the dominating features. Among nitrogen oxides (NO x ) we have considered the following molecules NO, NO 2 and N 2 O 4, and all the calculations were made for 1 : 1 systems. The both approaches exhibit quite satisfactory agreement with each other for the C 2 H 4 –NO system The sets of stationary points (minimum, saddle point) and the relative values of their energies due to the reaction coordinate were obtained. For each of the offered reaction mechanisms full reaction path were suggested and so the found stationary points are connected by reaction coordinate according to IRC procedure and the energetic profiles have been constructed. It was shown that chemical interactions are the mostly likely for “C 2 H 4 –NO 2 ” system, where two first potential barriers were relatively low and were equal to 12.7 and 16.3 kcal/mol. This fact is exceptionally important for the reactions in low temperature condensates of the components.