Dynamics of chemical and charge-transfer reactions of molecular dications Part V. An experimental and theoretical study of reactions between CHCl2+ and Ar, Kr and Xe

Abstract

Non-dissociative charge-transfer processes between the dication CHCl²⁺ and noble gases Ar, Kr and Xe were investigated in crossed-beam scattering experiments. Translational energy distributions of the charge-transfer product CHCl⁺ revealed that two isomers of CHCl²⁺ of different energetics were taking part in these processes. In reactions with Ar, the charge-transfer products are formed mainly in reactions of the CCl–H²⁺ isomer (its electronic states are indicated by the prefix “i” for isomer) in the ground (iS₀) and first excited (iT₁) state, leading to the ground (iD₀) and first excited (iD₁) state of the cation CCl–H⁺. Part of the vibrationally excited product (iD₀) may dissociate further to give CCl⁺ + H. The main reaction in the system with Ar is, however, a proton transfer process of the other isomer, H–CCl²⁺ (electronic states without prefix), H–CCl²⁺(S₀) leading to CCl⁺ + ArH⁺. The prevailing reaction with Kr is charge transfer leading to dication–cation transitions: CClH²⁺(iS₀) → CClH⁺(iD₀), CClH²⁺(iS₀) → CClH⁺(iD₁), and CClH²⁺(iT₀) → CClH⁺(iD₁) and Kr⁺ in both spin–orbit states. The main channels in reactions with Xe result from HCCl²⁺(S₀) giving HCCl⁺(D₀) + Xe⁺(²P_1/2), and CClH²⁺(iS₀) leading to CClH⁺(iD₁) + Xe⁺(²P_1/2).