Unconventional S(N)2 retention pathways induced by complex formation: High-level dynamics investigation of the NH2- + CH3I polyatomic reaction

摘要

Investigations on the dynamics of chemical reactions have been a hot topic for experimental and theoretical studies over the last few decades. Here, we carry out the first high-level dynamical characterization for the polyatom-polyatom reaction between NH2- and CH3I. A global analytical potential energy surface is developed to describe the possible pathways with the quasi-classical trajectory method at several collision energies. In addition to S(N)2 and proton abstraction, a significant iodine abstraction is identified, leading to the CH3 + NH2 center dot center dot center dot I(-) products. For S(N)2, our computations reveal an indirect character as well, promoting the formation of CH3 center dot center dot center dot NH2 complexes. Two novel dominant SN2 retention pathways are uncovered induced by the rotation of the CH3 fragment in these latter CH3 center dot center dot center dot NH2 complexes. Moreover, these uncommon routes turn out to be the most dominant retention paths for the NH2- + CH3I S(N)2 reaction. Published under an exclusive license by AIP Publishing.