Rare gas–iodine complexes in the ion-pair states

Abstract

Abstract Luminescence and luminescence excitation spectra in the vicinity of the optical–optical double resonance transitions to the I 2 ( f 0 g + , v f = 8 and 9, J f ≈ 55) levels have been measured at the bulb conditions for the I 2 + Rg mixtures (Rg = He, Ar, Xe) at the rare gas pressures 2–20 Torr and room temperature. Luminescence attributed to the RgI 2 complexes in the f 0 g + , F 0 u + and E 0 g + ion-pair states has been observed for the first time. It is argued that the complexes can be formed by direct optical excitation from the RgI 2 ( B 0 u + ) complexes or { Rg + I 2 ( B 0 u + ) } colliding pairs. Besides, the RgI 2 complexes in the f 0 g + , F 0 u + and E 0 g + ion-pair states can be formed in nonadiabatic internal conversion processes from the RgI 2 ( f 0 g + ) one. The complexes have rather long lifetime, especially in the case of Xe, and decay radiatively and nonradiatively forming I 2 molecules in different ion-pair states.