Vibrational level structure of highly excited SO2 in the electronic ground state. II. Vibrational assignment by dispersed fluorescence and stimulated emission pumping spectroscopy

Abstract

The dispersed fluorescence (DF) spectra for the fluorescence emitted from eight single rovibronic levels in the C̃ 1B2 state are observed. The vibrational quantum numbers for these levels are (v′1,v2,v′3) =(0,0,0), (0,1,0), (0,2,0), (0,0,2), (1,0,0), (1,1,0), (1,2,2), and (3,1,0). The 484 vibrational levels distributed between 4300 and 21 600 cm−1 in the electronic ground state X̃ 1A1 are identified based on the assignment of the 1388 transitions in the DF spectra. The vibrational level energy is expressed by an anharmonic expansion with 19 coefficients and the vibrational quanta for the three normal modes. The combination analysis of the DF and stimulated emission pumping spectra having the same upper rovibronic level clarifies the vibrational level structure in the vibrationally highly excited region above 17 000 cm−1.