SHENGHAI WU, GALEN SEDO, ERIK M. GRUMSTRUP AND KENNETH R. LEOPOLD, Department of Chemistry, University of Minnesota, Minneapolis, MN 55455.
Understanding intermolecular interactions involving open shell systems is important to both combustion and atmospheric research. In this talk, we present microwave spectra of O2--HF and O2--DF, and analysis of their hyperfine structure. Last year, spectra were reported\footnoteE. M. Grumstrup, G. Sedo and K. R. Leopold, The 61^st Symposium on Molecular Spectroscopy TE08 (2006) for six different pure rotational transitions of O2--HF , though at the time, the analysis of the hyperfine structure was still incomplete. A simultaneous fit of microwave and infrared data was also described. In this talk, we report a complete analysis of the hyperfine structure for O2--HF and a new global fit including microwave and infrared frequencies. New assignments for the F1 quantum numbers, together with complete assignment of F quantum numbers has allowed all observed transitions of O2--HF to be fully analyzed with confidence. Calculated spectral intensities are also consistent with experimental observation. The Fermi contact parameters for the two nuclei are found to have opposite signs, consistent with a simple model based on spin polarization. Progress on analysis of magnetic and nuclear quadrupole hyperfine structure in O2--DF and global fit with IR data will be reported. The derived hyperfine parameters unambiguously establish the correspondence between the magnetic hyperfine constants and the two nuclei of the H(D)F.