Rovibrational spectra of SO2-containing van der Waals complexes in the v1 region of SO2. Part I. N2-SO2 and OC-SO2

Rovibrational absorption spectra of the N2-SO2 and OC-SO2 complexes in the v1 symmetric stretching region of SO2 have been measured in a supersonic slit jet expansion using a segmented rapid-scan quantum cascade laser spectrometer. The observed transitions are of c-type for both complexes. The possible tunneling splittings for N2- SO2 or OC-SO2 are too small to be resolved under our experimental conditions. The observed infrared transitions are assigned and fitted using a standard S-reduced Watson asymmetric top Hamiltonian, yielding accurate molecular constants in the excited vibrational state. The band origins of N2-SO2 and OC-SO2 are determined to be 1152.574299(63) cm-1 and 1153.141389(45) cm-1, which shows a blue-shift from that of the monomer by about 0.86 cm-1 and 1.43 cm-1, respectively.