Rovibrational spectra of SO2-containing van der Waals complexes in the v1 region of SO2. Part II. SO2–H2O and SO2–D2O

Jet-cooled rovibrational absorption spectra of SO₂–H₂O and SO₂–D₂O complexes have been measured in the v₁ symmetric stretching region of SO₂ around 1151 cm⁻¹ using a segmented rapid-scan quantum cascade laser spectrometer. The rovibrational spectrum of SO₂–D₂O has also been measured in the v₂ bending region of D₂O around 1178 cm⁻¹. The tunneling splittings caused by the internal rotation of the water unit could not be resolved under our experimental conditions. The observed rovibrational transitions for these two complexes are analyzed using a standard A-reduced Watson asymmetric top Hamiltonian, yielding precise molecular constants for the excited vibrational states. The experimental band-origins are 1156.713866(70) cm⁻¹ for SO₂–H₂O and 1156.819797(66) cm⁻¹ for SO₂–D₂O in the v₁ region of SO₂, and 1180.177901(58) cm⁻¹ for SO₂–D₂O in the v₂ region of D₂O.