Observation of a new electronic state of CO perturbing W ¹Π(v=1)

A N Heays; M Eidelsberg; G Stark; J L Lemaire; L Gavilan; S R Federman; B R Lewis; J R Lyons; N de Oliveira; D Joyeux

doi:10.1063/1.4897326

Observation of a new electronic state of CO perturbing W ¹Π(v=1)

J Chem Phys. 2014 Oct 14;141(14):144311. doi: 10.1063/1.4897326.

Authors

A N Heays¹, M Eidelsberg², G Stark³, J L Lemaire², L Gavilan², S R Federman⁴, B R Lewis⁵, J R Lyons⁶, N de Oliveira⁷, D Joyeux⁷

Affiliations

¹ Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands.
² Observatoire de Paris, LERMA and UMR 8112 du CNRS, 5 place Jules Janssen, 92195 Meudon, France.
³ Department of Physics, Wellesley College, Wellesley, Massachusetts 02481, USA.
⁴ Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606, USA.
⁵ Research School of Physics and Engineering, The Australian National University, ACT 0200 Canberra, Australia.
⁶ School of Earth and Space Exploration, Arizona State University, 781 S. Terrace Rd, Tempe, Arizona 85281, USA.
⁷ Synchrotron SOLEIL, Orme de Merisiers, St. Aubin, BP 48, 91192 Gif sur Yvette Cedex, France.

PMID: 25318726
DOI: 10.1063/1.4897326

Abstract

We observe photoabsorption of the W(1) ← X(0) band in five carbon monoxide isotopologues with a vacuum-ultraviolet Fourier-transform spectrometer and a synchrotron radiation source. We deduce transition energies, integrated cross sections, and natural linewidths of the observed rotational transitions and find a perturbation affecting these. Following a deperturbation analysis of all five isotopologues, the perturbing state is assigned to the v = 0 level of a previously unobserved (1)Π state predicted by ab initio calculations to occur with the correct symmetry and equilibrium internuclear distance. We label this new state E″ (1)Π. Both of the interacting levels W(1) and E″(0) are predissociated, leading to dramatic interference effects in their corresponding linewidths.