Symmetry-induced kinetic isotope effects in the dissociation dynamics of CHCl3+ and CHCl4−

Abstract

Loss of Cl from CHCl3+ with little excess energy is found to proceed via two distinct pathways, the reaction channel which is being followed is determined by a symmetry-induced kinetic isotope effect. Computational investigations suggest competition between a statistical adiabatic process and a process of electronic predissociation. For CHCl4− and CH2Cl3−, rotational predissociation contributes to the kinetic isotope effects for all isotopomers, whereas the particularly large effect observed for CH35Cl337Cl− also originates from symmetry-induced degeneracy of vibrational modes in the C3V point.