ELECTRONIC SPECTROSCOPY OF JET-COOLED HCP$^+$

Author Institution: Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055Laser-induced fluorescence spectra of jet-cooled HCP$^+$ and DCP$^+$ have been obtained with the pulsed discharge technique using HCP/DCP and argon precursor mixtures. Most of the excited state vibrational fundamentals have been observed and a set of vibrational constants obtained. High resolution spectra of the $^2$\Pi$_{3/2}$ components of the $0_0^0$ bands of both isotopomers have been recorded, and these spectra show resolved phosphorus hyperfine structure which allowed the determination of the excited state Fermi contact parameter. The $B$ values were used to obtain the ground and excited state effective geometric parameters as $r_0^{\prime \prime}$(CH) = 1.077(2) \AA, $r_0^{\prime \prime}$(CP) = 1.6013(3) \AA, $r_0^{\prime }$(CH) = 1.082(2) \AA and $r_0^{\prime }$(CP) = 1.5331(3) \AA. The ground state vibrational energy levels reported in the literature were fitted to a Renner-Teller hamiltonian that included the effects of angular momentum coupling as well as spin-orbit, vibrational anharmonicity and Fermi resonance effects