Electronic energy transfer between O2 and CO dopants in Ar crystals

Abstract

Excitation spectra of Ar crystals doubly doped with O2 and CO show the a 3Π, a’ 3∑+, d 3Δ, e 3∑−, A 1Π vibrational progressions of CO as well as the Schumann Runge bands ( B 3∑− u ) and the following dissociation continuum of O2. In emission the Cameron bands (a 3Π) of CO and the Herzberg bands C 3Δ u of O2 have been observed. No electronic energy transfer from CO to O2 or vice versa occurs. This rules out an intramolecular V–E conversion of high vibrational quanta (v=32) in the electronic ground state of CO to the a 3Π (v=3) state of CO and subsequent electronic energy transfer to O2 in the recently reported IR‐induced UV‐visible fluorescence in matrix‐isolated CO thus supporting the other suggested intermolecular V–E and V–V transfer routes.