J. Phys. Chem. A 123 (2019) 8562-8570

Vibrational Autodetachment from Anionic Nitroalkane Chains: From Molecular Signatures to Thermionic Emission

Christopher L. Adams,^† Klavs Hansen,^*,‡,§ and J. Mathias Weber^*,†

† JILA and Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0440, United States

‡ Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 300072 Tianjin, P. R. China

§ Department of Physics, Gothenburg University, SE-405 30 Gothenburg, Sweden

ABSTRACT:

We report the kinetic energy distributions in electron autodetachment from nitroethane, 1-nitropropane, and 1-nitrobutane anions upon laser excitation of CH stretching modes measured using velocity map electron imaging. In striking contrast to the case of nitromethane, the kinetic energy distributions show almost no distinct vibrational features, and they can be described by thermionic emission, relating the shape of the distributions to the electron capture cross section of the neutral molecule. The data suggest that a classical description is warranted above ca. 20 meV electron kinetic energy. At lower energies, quantum effects suppress the attachment cross section.