Low-energy electron interactions with molecules and clusters: Electron induced proton transfer, solvated electron, and diffuse electron states.

摘要

In this work, techniques of mass spectrometry and photoelectron spectroscopy were used to study several categories of negative ions of various molecules and molecular clusters.; Studies of negative ions of biologically relevant systems, i.e., studies of electron interactions with biomolecules have implications for radiation induced damage by low energy electrons. Electron attachment to dimers that were composed of nucleic acid base as one constituent and weak acid as the second constituent, had a great impact on these complexes, causing intermolecular proton transfer. Electron attachment to amino acid, arginine that exists in its canonical form as a neutral, caused its transformation into its zwitterionic form in the produced anion. Several categories of anions with diffuse electron states were studied. Ethylene carbonate is a polar molecule that binds an excess electron with an electric dipolar field. In related work, dipole electron binding in gauche-succinonitrile and very rare quadrupole electron binding in trans-succinonitrile was observed. Two new double Rydberg anions (DRA), (N6H19+) = and (N7H22+)=, were produced. DRAs are unique species that are composed of closed-shell cations with two electrons in diffuse orbitals. The measured transition energies of DRAs to the first excited states of their corresponding neutrals further confirmed our previous results that these species are negative ions of neutral Rydberg molecules. The nature of the solvated electron, the central species of radiation chemistry, was explored by studying doped water clusters (the dopant molecule was ethylene-glycol and glycerol). Measurements of charge-dopant interaction energies are useful indicators of the extent of electron internalization in these complexes. Electron attachment to a gas phase hydrogen bonded HCl-NH 3, complex with no ionic character, caused proton transfer from HCl to NH3 resulting in the anionic salt, ionic negative complex with charge separated moieties, (NH4+Cl-) -.