SPECTROSCOPY OF METASTABLE SPECIES IN A FREE-JET EXPANSION - THE D'[-A' TRANSITION OF IBR

The A'2(3PI) state of IBr is observed in a free-jet expansion of IBr in Ar, following photolysis with ArF laser irradiation. Laser excitation spectra are recorded for the D'2 (3P2)C <-- A' transition. The data include high-resolution, rotationally analyzed measurements for 34 bands in (IBr)-I-127-Br-79 and 37 in (IBR)-I-127-Br-81, plus bandhead measurements for >300 bands recorded in low resolution. The data span upsilon'' = 0-5 and upsilon' = 24-97. The results from the analysis of these data are merged with preliminary results from a study of the D' --> A' emission spectrum to yield spectroscopic constants valid for upsilon' = 0-97, upsilon'' = 0-22. The primary constants (in cm-1) are DELTAT(e) = 28 018.98, omega(e)' = 123.088, w(e)x(e)' = 0.2820, B(e)' = 0.02853, omega(e)'' = 147.633, w(e)x(e)'' = 1.258, and B(e)'' = 0.04298. (C) 1994 Academic Press, Inc.