title: Spectroscopy of Ethylenedione.
abstract: The long sought-after, intrinsically short-lived molecule ethylenedione (OCCO) was observed and investigated by anion photoelectron spectroscopy. The adiabatic electron affinity of its quasi-bound (3)Σ(g)(-) state is 1.936(8) eV. The vibrational progression with a 417(15) cm(-1) frequency observed within the triplet band corresponds to a trans-bending mode. Several dissociative singlet states are also observed, corresponding to two components of the (1)Δg state and the (1)Σ(g)(+) state. The experimental results are in agreement with theoretical predictions and constitute the first spectroscopic observation and characterization of this elusive compound.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 (USA).
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Dixon
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 (USA).
authors.forename: Tian
authors.initials: T
authors.lastname: Xue
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 (USA). sanov@u.arizona.edu.
authors.forename: Andrei
authors.initials: A
authors.lastname: Sanov
keywords: anions; diradicals; electronic structure; photoelectron spectroscopy; transient molecules