Ion-Velocity Imaging Study of Dissociative Charge Exchange Reactions between Ar⁺ and trans-/cis-Dichloroethylene

Dissociative charge exchange reactions between Ar⁺ ion and trans-/cis-dichloroethylene (trans-/cis-C₂H₂Cl₂) are investigated with the ion-velocity imaging technique. The dechlorinated product C₂H₂Cl⁺ is the predominant, and most of this product show the spatial distribution around the target, implying that the dissociation occurs in the large impact-parameter collision and via the energy resonant charge transfer. Meanwhile, a few C₂H₂Cl⁺  locate around the center-of-mass, which is attributed to the fragmentation of intimate association between C₂H₂Cl₂ and Ar⁺ or in the small impact-parameter collision. The product C₂HCl⁺ exhibits the velocity distribution features similar to those of C₂H₂Cl⁺. The rarest product C₂HCl₂⁺ shows the distributions around the molecular target, due to the quick dehydrogenation after the energy-resonant charge transfer in the large impact-parameter collision.