JINJUN LIU, Department of Chemistry, University of Louisville, 2320 S. Brook St., Louisville, Kentucky 40292.; DMITRY G. MELNIK AND TERRY A. MILLER, Laser Spectroscopy Facility, Department of Chemistry, The Ohio State University, 120 W. 18th Ave., Columbus, Ohio 43210.
The previously obtained 2A'- 2A'' and 2A'- 2A' laser-induced fluorescence (LIF) spectra of jet-cooled cyclohexoxy radical (c-C6H11O) have been analyzed and simulated using the coupled-two-state model presented in the preceding talk. The rotational and fine structure of the nearly degenerate 2A'' and 2A' states is reproduced using one set of molecular constants including rotational constants, spin-rotation constants, effective spin-orbit constants (a e d) and the vibronic energy separation between the two states ( E). While the energy level structure could be reproduced by only effective spin-rotation constants (without the spin-orbit constant), the spin-orbit interaction introduces transitions that have no intensity using the separate-states asymmetric rotor model. Rotational and fine-structure analysis using the two-state model has proven to be an effective method to separate the first order electron-spin-molecular-rotation constants from the effective spin-rotation constants, and to decouple the spin-orbit splitting (a e d) and the vibronic energy separation ( E), both of which contribute to the experimentally observed energy separation between the two coupled states ( E - ). Isopropoxy (discussed in the preceding talk), cyclohexoxy, and other molecules in nearly degenerate electronic states provide unique cases bridging the gap from symmetrically degenerate states, e.g., ground 2E state of methoxy, and the Born-Oppenheimer limit of unperturbed electronic states.