Communication: On the first ionization threshold of the C2H radical

B Gans; G A Garcia; F Holzmeier; J Krüger; A Röder; A Lopes; C Fittschen; J-C Loison; C Alcaraz

doi:10.1063/1.4973383

Communication: On the first ionization threshold of the C₂H radical

J Chem Phys. 2017 Jan 7;146(1):011101. doi: 10.1063/1.4973383.

Authors

B Gans¹, G A Garcia², F Holzmeier³, J Krüger², A Röder³, A Lopes⁴, C Fittschen⁵, J-C Loison⁶, C Alcaraz⁴

Affiliations

¹ Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
² Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP 48, F-91192 Gif sur Yvette Cedex, France.
³ Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
⁴ Laboratoire de Chimie Physique, UMR 8000 CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, Bât. 350, Centre Universitaire Paris-Sud, F-91405 Orsay Cedex, France.
⁵ Université Lille, CNRS, UMR 8522-PC2A-Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France.
⁶ Institut des Sciences Moléculaires, UMR 5255 CNRS, Université de Bordeaux, Bât. A12, 351 cours de la Libération, F-33405 Talence Cedex, France.

PMID: 28063431
DOI: 10.1063/1.4973383

Abstract

The slow photoelectron spectrum of the ethynyl radical has been recorded for the first time by using the DESIRS beamline of the SOLEIL synchrotron facility. Ethynyl was generated using a microwave discharge flow tube. The observation of the X⁺Π3←XΣ+2 transition allowed the first direct measurement of the adiabatic ionization threshold of this radical (E_I = 11.641(5) eV). The experimental results are supported by ab initio calculations. Our preliminary investigation of the cationic ground state potential energy surfaces predicts a non-negligible Renner-Teller effect which has not been discussed previously.