Non-Covalent Structures of Negative Ions Formed upon Dissociative Electron Attachment to Molecules

Abstract

Electron attachment to 1-chloronaphthalene molecules is studied with the aid of the dissociative electron attachment spectroscopy. It is shown that the dominant channel for the decay of molecular ions is the formation of Clˉ ions in three resonances at 0.7, 1.5, and 3.0 eV. The [M–H]ˉ and [M–Cl]ˉ ions are observed at energies from 3.5 to 8.5 eV and exhibit formation cross sections that are less by two-to-three orders of magnitude. Long-lived molecular ions are not detected. The calculations in the DFT CAM B3LYP/6-311+G(d,p) approximation predict the presence of six stable anionic structures in which the chlorine anion is coordinated with the neutral residue via noncovalent H–Clˉ–H bonds. The electron affinity of the most stable of these structures coincides with the experimental value EA_a = 0.2771 ± 0.003 eV. Such results are in agreement with the existing data on the dissociative electron attachment to molecules of bromine-substituted biphenyls, naphthalenes, and anthracenes and proves the existence of anionic structures with non-covalent H–Hal–H bonds. Such non-covalent anion structures must be extremely reactive, which makes them promising for the synthesis of self-assembling hydrocarbon nanomembranes.