THE MICROWAVE SPECTRUM OF THE LiO RADICAL

$^{1}$ S. M. Freund, E. Herbst, R. P. Mariella, Jr., and W. Klemperer, J. Chem. Phys. 56, 1467 (1972)Author Institution: Institute for Molecular ScienceThe rotational spectra of the $^{7}LiO$ radical in the $v=0$ and $v=1$ vibrational states were observed in millimeter and submillimeter wave region. The LiO radical was generated by the reaction of lithium vapor with $N_{2}O$ in a heat pipe cell. The rotational and centrifugal distortion constants, -type doubling constants, spin-orbit interaction constant, and hyperfine interaction constants were derived through analysis of the rotational spectra observed in the present study, combined with the radio-frequency spectra of -type transitions reported by S. M. Freund $et al.^{1}$ The LiO radical was confirmed to have a $^{2}\Pi_{i}$ ground electronic state with an exceptionally large -type doubling constant, as in the case of NaO. A pure precession hypothesis applied to the observed ``p'' constant gives the $\Sigma-\Pi$ energy separation to be $2565 cm^{-1}$