Theoretical Studies on OH⁻+NH₂Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen

The S N 2 and proton transfer (PT) pathways for [Formula: see text]Cl reaction are represented by employing various electronic structure computations. Both back-side S N 2 and PT channels are exothermic and stationary points of PESs are below the reactant asymptote. Overall, the PES is similar to the C-centered S N 2 reactions. Conversely, ion-dipole complex was not found for [Formula: see text]Cl system. The N–HOH/NH–Cl hydrogen bond characterizes on either side of the reaction barrier of nitrogen complexes. Moreover, a halogen-bonded complex (HO − –ClNH 2 ) and two types of H-bond complexes (HONH 2 –Cl − and Cl − –HONH 2 ) were described, predicting an important role in dynamics. The PT pathway may be the major channel in the title system, which is contradictory to [Formula: see text]Cl and [Formula: see text]Cl reactions. Here, MP2, B3LYP and CAM-B3LYP methods show overall excellent consistency with CCSD(T)/CBS energies and are recommended to carry out dynamics simulations.