Ion-pair states in the complexes of iodine molecule with rare gases

The luminescence excitation spectra and the luminescence spectra of the I2 + Rg (Rg = He, Ar, Xe; pRg = 2–20 Torr) mixtures measured at room temperature by the method of double optical resonance in the spectral range corresponding to the population of the I2(f0g+, vf = 8.9) levels and in its vicinity are analyzed in this work. The experimental data and their interpretation, according to which these spectra can be explained by the energy transfer in the intermediate I2(B0u+) and final I2(f0g+) states of the free iodine molecule rather than by the optical population, luminescence, and predissociation of the ion-pair RgI2(IP) complexes, are discussed. It is shown that these data can be explained only with account taken of the optical population of the RgI2(IP) complexes.