Mechanism for the gas-phase reaction between N3 and NO2: A theoretical study

In an attempt to understand the mechanism of the reaction of azide radical with nitrogen dioxide, the singlet and triplet potential energy surfaces (PESs) for the gas-phase reaction between N3 and NO2 have been investigated by means of G3B3, CBS-QB3, and G2M(CC, MP2) levels of theory. All the pathways on the singlet PES consist of the barrierless formation of a complex as the first reaction step, followed by isomerization and dissociation to the products. Furthermore, the minimum energy crossing point (MECP) between the singlet and triplet potential energy surfaces is found with the B3LYP/6-311++G(d,p) level. The products 2NO + N2 are found to be major and predominant on both the singlet energy surface and the triplet energy surface, whereas 2N2O are expected to be minor products.