Observation of bands among the four lowest pseudorotational states of 1,3-dioxolane

The rotational transitions belonging to the pseudorotational bands n=0→1, n=2→3, and n=0→3 have been experimentally observed for 1,3-dioxolane in the spectral region of 153-364 GHz in a supersonic jet environment using the FASSST absorption spectrometer. Based on these observations, the symmetry ordering and the energy spacings of the four lowest states, n=0,1,2,3, have been established. The totality of the available data on this molecule, including those available from previously reported microwave studies has been analyzed, and a set of molecular constants has been obtained. Using the newly determined frequencies of the pseudorotational bands, along with the frequencies of the previously reported pseudorotational bands in the IR spectrum region, an empirical potential surface of 1,3-dioxolane has been obtained. The results of this analysis are compared to the potential surface and rotational constants obtained from quantum chemistry calculations.