Mixed Quantum-Classical Reaction Path Dynamics of HCl Elimination from Chloroethane

Abstract

The dynamics of four-centered HCl elimination from chloroethane are studied using a mixed quantum-classical method based on a reaction path Hamiltonian. Both the structural details of the reaction and the partitioning of the exit-channel potential energy to the products are analyzed. The minimum energy path was calculated at the B3LYP/6-311++G(2d,2p) level of theory, which was followed by energy-partitioning dynamics computations. Selective vibrational excitation of the HCl product was observed, leading to a vibrational state distribution in good agreement with experiment. Differences between HCl elimination from C(2)H(5)Cl and HF elimination from C(2)H(5)F, particularly in the ethylene fragment, were observed and are discussed.