High-Resolution Spectroscopy of Asymmetric Top Molecules in Non-Singlet Electronic States: ν1 + ν3 Band of the ClO2 Molecule

Using a Bruker IFS 125 HR Fourier spectrometer, the high-resolution spectrum of the (OClO)-O-16-Cl-35-O-16 molecule is recorded in the region of the band, in which more than 2000 transitions with the maximum quantum numbers N-max = 59 and K-a(max) = 16 are identified. The obtained experimental data are analyzed based on the model from the work [Phys. Chem. Chem. Phys. 23 (8), 4580-4596 (2021)], which takes into account the existence of spin-rotational interactions in the molecule. The root-mean-square deviation of rotational-vibrational energies from the calculated values for the (101) state was d(rms)= 2.5 x 10(-4) cm(-1), which is 35 times better than the data known from the literature.