High-resolution spectroscopy in non-singlet electronic states of asymmetric-top molecules: the $\nu_1+\nu_3$ band of ClO$_2$

Using a Bruker IFS 125 HR Fourier spectrometer, the high-resolution spectrum of $^{16}$O$^{35}$Cl$^{16}$O molecule was recorded in the region of the $\nu_1+\nu_3$ band, in in which more than 2000 transitions with maximum values $N^{\mathrm{max}}$ = 59 and $N^{\mathrm{max}}_a$ = 16 were interpreted. The analysis of the obtained experimental information was performed on the basis of the model from (Phys. Chem. Chem. Phys. 2021. V. 23. N. 8. P. 4580–4596) which takes into account the presence of spin-rotation interactions in the molecule. The standard deviation was $d_{\mathrm{rms}}$ = 2.5 $\cdot$ 10$^{-4}$cm$^{-1}$ and is 35 times higher than the result known in the literature.