LASER INDUCED FLUORESCENCE SPECTROSCOPY OF RHODIUM FLUORIDE

Rhodium monofluoride has been observed and spectroscopically characterized for the first time. RhF molecules were produced under jet-cooled conditions in a laser vaporization molecular beam source by the reaction of a laser-vaporized rhodium plasma with $SF_{6}$ doped in helium, and studied with laser-induced fluorescence spectroscopy under both medium-and high-resolution. More than 25 LIF bands have been observed between 18 500 and $24 500 cm^{-1}$ and five of these have been recorded at 200 MHz resolution. All bands of appreciable intensity have been rotationally analyzed. The ground electronic level has $\\Omega = 2$, which is attributed to an inverted $^{3}\\Pi$ state from the $2\\delta^{4} 12\\sigma^{1}6\\pi^{3}$ electron configuration. The ground level rotational constants are $B = 0.27245 cm^{-1}, D = 1.035 \\times 10^{-7} cm^{-1}$. Very small ground level $\\Lambda$ - doublings are evident in the spectrum. Excited states having $\\Omega = 1, 2$ and 3 have been identified. Dispersed fluorescence spectroscopy from eleven excited levels has been used to locate a large number of low-lying vibronic states within the energy range up to $8000 cm^{-1}$. A ground state vibrational interval of ${\\sim}575 cm^{-1}$ is suggested.