The molecular structure and a Renner-Teller analysis of the ground and first excited electronic states of the jet-cooled CS_2~+ molecular ion

摘要

The A~2PI_u-X~2PI_g electronic band system of the jet-cooled CS_2~+ ion has been studied by laser-induced fluorescence and wavelength-resolved emission techniques.The ions were produced in a pulsed electric discharge jet using a precursor mixture of carbon disulfide vapor in high-pressure argon.Rotational analysis of the high-resolution spectrum of the ~2PI_(3/2) component of the 0_0~0 band gave linear-molecule molecular structures of r"_0=1.5554(10) A and r'_0= 1.6172(12) A.Renner-Teller analyses of the vibronic structure in the spectra showed that the ground-state spin-orbit splitting (A=-447.0 cm~(-1)) is much larger than that of the excited state (A=-177.5 cm~(-1)),but that the Renner-Teller parameters are of similar magnitude and that a strong v_1-2v_2 Fermi resonance occurs in both states.Previous analyses of the vibronic structure in the ground and excited states of the ion from pulsed field-ionization-photoelectron data are shown to be substantially correct.