Optical population of gerade and ungerade iodine ion-pair states via MI2 vdW complexes of valence states correlating with the third dissociation limit, M = I2, Xe

Abstract

The results of measurements and analysis of excitation spectra of the λlum=2350Ǻ luminescence corresponding to I2(D0+u→X0+g) transition as well as luminescence at λlum=3400Ǻ, where I2(D’2g→A’2u and/or β1g→A1u) transitions occur, observed after three-step, λ1+λf+λ1, λ1=5321–5508.2Ǻ, λf=10644.0Ǻ, laser excitation of pure iodine vapour and I2+Xe mixtures at room temperature are presented. Luminescence spectra in the λlum=2200–3500Ǻ spectral range are also analyzed. We discuss three alternative mechanisms of optical population of the IP states. In our opinion, the mechanism including the MI2, M=I2, Xe, complexes is the most probable at least in the λ1≈5321–5480Ǻ, λ1≈5508Ǻ spectral ranges and for population of the states which luminescence occur at λlum≈3400Ǻ.