Structure, electronic relaxation and vibrational predissociation of the electronically excited SO2(C̃)Ar complex

Fluorescence excitation spectra of SO2Ar generated in a supersonic expansion near the SO2 C̃ → X̃, 000, 201, and 302 bands have been obtained. Three features red-shifted by 82, 60 and 41 cm−1 from monomer bands are assigned to the SO2Ar complex. The rotational constants of SO2(C̃)Ar are determined to be A = 0.2769 cm−1, B = 0.0520 cm−1 and C = 0.0488 cm−1. The corresponding complex structure is obtained. Rapid non-radiative decay induced by the Ar atom has been observed for the 000 level of the C̃ state complex. Vibrational predissociation is identified for the (010) and (002) levels, 377 and 560 cm−1 above the band origin.