Velocity map imaging spectroscopy of C2H-and C2D-: A benchmark study of vibronic coupling interactions

Benjamin A. Laws, Zachariah D. Levey, Andrei Sanov, John F. Stanton, Timothy W. Schmidt, Stephen T. Gibson

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


High-resolution velocity-map imaged photoelectron spectra of the ethynyl anions C2H- and C2D- are measured at photon wavelengths between 355 and 266 nm to investigate the complex interactions between the closely lying X 2ς+ and A 2Π electronic states. An indicative kinetic energy resolution of 0.4%, together with the full angular dependence of the fast electrons, provides a detailed description of the vibronically coupled structure. It is demonstrated that a modest quadratic vibronic coupling model, parameterized by the quasidiabatic ansatz, is sufficient to accurately recreate all the observed vibronic interactions. Simulated spectra are shown to be in excellent agreement with the experimental data, verifying the proposed model and providing a framework that may be used to accurately simulate spectra of larger C2nH monohydride carbon chains. New spectral assignments are supported by experimental electron anisotropy measurements and Dyson orbital calculations.

Original languageEnglish (US)
Article number044305
JournalJournal of Chemical Physics
Issue number4
StatePublished - Jul 28 2022
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry

Cite this