title: Counter-ion perturbation of the fragmentation pathways of multiply charged anions: evidence for exit channel complexes on the fragmentation potential energy surfaces.
abstract: We report the first low-energy collisional excitation measurements and density functional theory calculations to characterize the ground state potential energy surfaces of contact ion-pair complexes that contain multiply charged anions (MCAs). Excitation of K+.Pt(CN)(4) (2-) and K+.Pt(CN)(6) (2-) result in fragmentation products associated with decay of the isolated constituent dianions, revealing that the ground state ion-pair surfaces are dominated by the intrinsic characteristics of the MCA. This observation is important since it indicates that counter-ion complexation only weakly perturbs the electronic structure of an MCA. For K+.Pt(CN)(4) (2-), where the Pt(CN)(4) (2-) dianion decays with production of two ionic fragments, we observe evidence for the existence of a novel exit-channel complex corresponding to a polar KCN salt unit bound to the Pt(CN)(3) (-) anion. The results described provide a basis for understanding the potential energy surfaces and fragmentation characteristics of other ion-pair complexes that involve MCAs.
authors.affiliation: Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Burke
authors.forename: William E
authors.initials: WE
authors.lastname: Boxford
authors.forename: Caroline E H
authors.initials: CE
authors.lastname: Dessent