CURRENT RESEARCH IN ROTATIONAL SPECTROSCOPY AT THE UNIVERSITY OF VALLADOLID

Abstract

We continue work on the rotational spectra of small ring molecules. The microwave and millimeter wave spectrum of azetidine in the ground and four excited states of the ring-puckering vibration have been analysed. The features associated to the inversion splttings of the $\mu_{c}$-type transition draw interesting conclusion about the potential energy surface of azetidine. A waveguide FT-MW spectrometer has been used to analyse the quadrupole hyperfine structure for all the observed states. Investigation in providing data on chlorofluorocarbon $molecules^{1}$ such as $CH_{2}FCl (FC-31), CHF_{2}Cl (FC-22), CHFCl-CH_{3} (FC - 151a)$ and $CHClF-CF_{3} (FC - 124)$ are under study. High resolution spectra by means of FT-MW spectroscopy allow a precise determination of quadrupole coupling constants and internal rotation parameters. Strong interaction have been observed between the $v_{6} = 2$ and $v_{5} = 1$ vibrational states of $CH_{2}F^{35}Cl$ molecule. On the basis of a Coriolis and Fermi coupling scheme more than 200 transitions have been analysed and precise values for rotation-vibration interaction parameters have been obtained.