15min:

YUAN-PERN LEE, Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043; A. J. MERER, Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, B. C., Canada V67 1Z1.

Dispersed phosphorescence spectra of the transition a ³B₁ - X ¹A₁ of ¹⁸O-labeled SO₂ in solid Ne were recorded in the spectral region 388-478 nm during laser excitation. As zero-phonon lines are well resolved, we were able to identify all three vibrational modes of the X ¹A₁ state, and to monitor emission from a specific isotopomer (in particular ¹⁶OS¹⁸O) to obtain its corresponding excitation spectra. The vibronic patterns of excitation spectra of S¹⁶O₂ and S¹⁸O₂ in the spectral range 351-388 nm are similar to those observed in the gaseous phase, with severely perturbed lines above a ³B₁ (110) at 27005 cm^-1. New lines in two groups were observed for ¹⁶OS¹⁸O; they are identified as lines associated with the ₃ of a ³B₁ and of b ³A₂. These observations enable us to report ₃ = 922 cm^-1 for a ³B₁, ₂ = 315 and ₁ = 771 cm^-1 for b ³A₂, and a false origin at 26653 cm^-1 for the b ³A₂ (001) - X ¹A₁ (000) transition of ¹⁶OS¹⁸O.