title: Measurements of Ionization Cross Sections by Molecular Beam Experiments: Information Content on the Imaginary Part of the Optical Potential.
abstract: In this work, we present and analyze in detail new and recent ionization cross section and mass spectrum determinations, collected in the case of He*, Ne*-H2O, -H2S, and -NH3 ionizing collisions. These sets of data, obtained under the same experimental conditions, are relevant to identify differences in the autoionization stereodynamics of the three hydrogenated molecules and on the selective role of the imaginary part of the optical potential. We demonstrate that in these autoionization processes hydrogen and halogen bonds are competing because they are controlling both real and imaginary components of the optical potential that drives the complete reaction dynamics. In particular, we found that both components critically depend on the angular and radial approach between the reagent partners in determining the collision dynamics.
authors.affiliation: Department of Civil and Environmental Engineering, University of Perugia , Via G. Duranti 93, 06125 Perugia, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Falcinelli
authors.affiliation: Department of Civil and Environmental Engineering, University of Perugia , Via G. Duranti 93, 06125 Perugia, Italy.
authors.forename: Marzio
authors.initials: M
authors.lastname: Rosi
authors.affiliation: Department of Chemistry, Biology and Biotechnologies, University of Perugia , Via Elce di Sotto, 8, 06123 Perugia, Italy.
authors.forename: Fernando
authors.initials: F
authors.lastname: Pirani
authors.affiliation: Department of Chemistry, University of Rome "La Sapienza" , 00185 Rome, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Stranges
authors.affiliation: Department of Civil and Environmental Engineering, University of Perugia , Via G. Duranti 93, 06125 Perugia, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Vecchiocattivi