Gas phase electronic spectrum of T-shaped AlC 2 radical

• Published in: The Journal of chemical physics 2009-08, Vol.131 (6), p.064305-064305-7
• Main Authors: Apetrei, C., Knight, A. E. W., Chasovskikh, E., Jochnowitz, E. B., Ding, H., Maier, J. P.
• Format: Article
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.3186758

Gas phase electronic transitions for the C ̃ B 2 2 ← X ̃ A 2 1 and D ̃ B 2 1 ← X ̃ A 2 1 band systems of T-shaped AlC 2 ( C 2 v ) radical have been measured in the 345-475 nm range. Vibrational analyses of both band systems are reported. Simulation of several rotationally resolved bands confirms previously obtained rotational parameters for the C ̃ B 2 2 state. The radical is produced by ablating an aluminum rod in the presence of acetylene gas. The resulting supersonic molecular beam is probed using both mass-selective resonant two-color two-photon ionization and laser induced fluorescence. Ab initio calculations and vertical electronic excitation energies help the assignment. Vibrational frequencies for the X ̃ A 2 1 , C ̃ B 2 2 , and D ̃ B 2 1 states have been determined. Rotational analysis of a number of bands yields spectroscopic constants for one vibronic state in the C ̃ B 2 2 manifold and the origin band of the D ̃ B 2 1 ← X ̃ A 2 1 system.