Negative ions of polar molecules

Abstract

The influence of a molecule's dipole moment on its ability to capture an electron into a stable bound state is examined. It is proved that, in the fixednuclei approximation, a value greater than 1"625 Debye for the dipole moment suffices to guarantee the existence of a discrete spectrum of negative ion states. Implications for Hartree-Fock calculations of negative ions are discussed. The interaction of electronic, vibrational and rotational motions in negative dipolar ions is studied, and conclusions are drawn for real molecules.

Attempts to calculate the electron affinity of acrylonitrile

“…Our results, combined with the analysis that leads to the critical dipole moment theorem about [ 7,8 1, suggest that the state of the acrylonitrile anion should be of u symmetry, resembling a Rydberg state, the electron distribution of the extra elec-tron being localized in the positively charged regions of acrylonitrile, that is, nearby the hydrogen atoms and possibly C3, and far from the electron rich areas, that is, the nitrogen atom and the C=C bond. Indication for this is provided the fact that the LUMO~ in neutral acrylonitnle is of a' (or a) symmetry for bases (111) to (V) which include diffuse functions, while bases (I) and (11) belong to a" (or T ) symmetry.…”

“…A classical theorem [7,8] In view of the dispersion of the theoretical results on acrylonitrile AEA presently available, the rather low experimental value (10.02 eV) for a conjugated molecule exhibiting a large dipole moment due to the strong electron attracting nitrile group, and the lack of rigorous theoretical treatments, we attempt in this contribution to compute the vertical ( VEA) and adiabatic ( AEA) electron affinities of acrylonitrile by various ab initio procedures using several basis sets.…”

Perspective: Electrospray photoelectron spectroscopy: From multiply-charged anions to ultracold anions

“…DBS was predicted to exist for neutral molecules with sufficiently large dipole moments (>2.5D) [130][131][132][133] and had been observed, [134][135][136][137][138] usually with very low binding energies. Excited DBSs near the detachment thresholds of anions were observed by Brauman and co-workers in photodetachment cross sections.…”

Gas-phase clustering reactions of NO2−, C2H3NO2−, C2H4NO2−, C2H5NO2− and C2H5NO4− with C2H5NO2

“…From the fundamental point of view, nitroalkanes are of interest since they have large dipole moments. It is well known that if the dipole moment of the system exceeds ∼2.5 Debye, then the "dipole-bound anion" may be formed [1][2][3]. Much attention has been directed recently to the formation and properties of the dipole and valence states of nitromethane anion, CH 3 NO 2 − , and its clusters [4][5][6][7][8][9].…”