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Updated: May 27, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Electron affinities, well depths, and vibrational spectroscopy of cis- and trans-HOCO
Christopher J Johnson1, Michael E Harding, Berwyck L J Poad
1Department of Physics, University of California-San Diego, La Jolla, California 92093-0340, USA.
Abstract:
We report vibrationally resolved photoelectron spectra of internally cold HOCO(-) and DOCO(-) anions at wavelengths near and well above the detachment threshold. These spectra are dominated by a strong Franck-Condon progression of three low-energy modes of the cis isomer, the first gas-phase measurement of these vibrations. Using highly resolved, near-threshold spectra we are able to reassign the electron affinities (EAs) of cis- and trans-HOCO to 1.51 ± 0.01 and 1.37 ± 0.01 eV, respectively. Using these EAs, well depths with respect to OH + CO are determined to be 1.07 ± 0.02 eV for trans-HOCO and 0.99 ± 0.02 eV for cis-HOCO. High-level ab initio calculations show excellent agreement with all experimental results. These values will be of direct use in thermochemical calculations and will help to aid in the identification of the HOCO radical in complex reactions.
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