Spectroscopy of Metastable Species in a Free-Jet Expansion: TheD′ ← A′ Transition in Br2

✍ Scribed by Todd A. Van Marter; Yanning Lu; Michael C. Heaven; Eunsook Hwang; Paul J. Dagdigian; Joel Tellinghuisen

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 307 KB
• Volume: 177
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.0146

✦ Synopsis

The A2 u ( 3 P) state of Br 2 is observed in free-jet expansions of UV-photolyzed BBr 3 /Ar mixtures and of electrically discharged Br 2 /Ar mixtures. Laser excitation spectra are recorded for the D2 g ( 3 P 2 ) R A transition, providing the first information about £ Å 0 in the A state. Thirty-one £ 0 0Љ bands spanning £ Å 23-47 are rotationally analyzed. The new results are combined with existing emission spectroscopic data for £ Å 0-6 and £Љ Å 5-21 (a total of 2940 assignments) to provide spectroscopic parameters which should be valid for £Љ Å 0-21 and £ Å 0-50. The key spectroscopic constants (cm 01 ) for 79 Br 2 are DT e Å 35 702.67, v e Å 150.86, v e x e Å 0.3911, vЉ e Å 162.8, v e xЉ e Å 1.84, B e Å 0.04243, BЉ e Å 0.05931, R e Å 3.1731 A ˚, and RЉ e Å 2.6838 A ˚. Fluorescence decay data are recorded for excitation of £ Å 24 and analyzed to yield an estimate of 11 ns for the lifetime of the D state.