High Vibrational States of Carbon Monoxide in Liquid Argon: Overtone Intensity Enhancement and Reactions with Oxygen

Article abstract of DOI:10.1021/j100354a014

Isotopic carbon monoxide <88percent (13)C(16)O, 12percent (13)C(18)O> dissolved in liquid argon was optically pumped to the ν = 1 level by a CW CO laser.This energy spontaneously redistributes by collisional up-pumping to populate high vibrational levels in the (13)C(18)O isotope.Fluorescence from levels up to ν = 37 in the heavier isotope was observed from the steady-state distribution.First, second, and third overtone fluorescence from high vibrational levels in the (13)C(18)O isotope were observed.The result of populating high vibrational levels in the (13)C(18)O isotope has led to the discovery of two phenomena.First, a comparison of the intensity of high overtone fluorescence against calculated gas-phase intensities shows a pronounced fluorescence enhancement due to the liquid environment.Second, CO2 production was observed from an O2-doped CO solution resulting from pumping by the infrared laser.The mechanisms for liquid-state collisional up-pumping, fluorescence enhancement, and infrared photochemical production of CO2 are discussed.