Vibrationally Resolved Inner-Shell Photoexcitation of the Molecular Anion C${}_2^{-}$

Abstract

Carbon $1s$ core-hole excitation of the molecular anion C${}_2^{-}$ has been experimentally studied at high resolution by employing the photon-ion merged-beams technique at a synchrotron light source. The experimental cross section for photo--double-detachment shows a pronounced vibrational structure associated with $1{\sigma }_u\to 3{\sigma }_g$ and $1{\sigma }_g\to 1{\pi }_u$ core excitations of the C${}_2^{-}$ ground level and first excited level, respectively. A detailed Franck-Condon analysis reveals a strong contraction of the C${}_2^{-}$ molecular anion by 0.2~Å upon this core photoexcitation. The associated change of the molecule's moment of inertia leads to a noticeable rotational broadening of the observed vibrational spectral features. This broadening is accounted for in the present analysis which provides the spectroscopic parameters of the C${}_2^{-}$ $1{\sigma }_u^{-1}3{\sigma }_g^2{}^2{\Sigma }_u^{+}$ and $1{\sigma }_g^{-1}3{\sigma }_g^2{}^2{\Sigma }_g^{+}$ core-excited levels.

8 pages, 5 figures, 1 table, accepted for publication in ChemPhysChem

References in corpus (6)

• Interatomic Coulombic Decay following Photoionization of the Helium Dimer: Observation of Vibrational Structure
• Laser Cooling of Molecular Anions
• Absolute cross sections for photoionization of Xe${}^{q+}$ ions (1 $\le$ q $\le$ 5) at the 3d ionization threshold
• Multiple photodetachment of carbon anions via single and double core-hole creation
• Spectroscopy and ion thermometry of C${}_2^{-}$ using laser-cooling transitions
• Photon-momentum-induced molecular dynamics in photoionization of N${}_2$ at $h\nu =40$ keV

Cited by in corpus (3)

• Franck-Condon Simulation of Vibrationally-Resolved X-ray Spectra for Diatomic Systems: Validation of Harmonic Approximation and Density Functional Theory
• Predicting Accurate X-ray Absorption Spectra for CN${}^{+}$, CN, and CN${}^{-}$: Insights from Multiconfigurational and Density Functional Simulations
• Unimolecular processes in diatomic carbon anions at high rotational excitation