Non-covalent structures of negative ions formed during the dissociative capture of electrons by molecules

Abstract

The method of dissociative electron attachment (DEA) spectroscopy was used to study the attachment of electrons to 1-chloronaphthalene molecules. It has been established that the dominant channel for the decay of molecular ions is the formation of Cl- ions in three resonances at 0.7, 1.5, and 3.0 eV. Ions [M-H]- and [M-Cl]- are observed at energies from 3.5 to 8.5 eV and have two to three orders of magnitude lower formation cross sections. Long-lived molecular ions were not registered. 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 to the neutral residue via noncovalent H-Cl^--H bonds. The electron affinity of the most stable of these structures coincides with the experimentally measured value EA_a=0.2771±0.003 eV. These results agree with the previously obtained data on the DEA of molecules of bromine-substituted biphenyls, naphthalenes, and anthracenes and confirm the existence of anionic structures with non-covalent H-Hal-H bonds. Such non-covalent anion structures should be extremely reactive, which makes them promising for the synthesis of self-assembling hydrocarbon nanomembranes. Keywords: Attachment of electrons to molecules, electron affinity, potential surface, DFT calculations.