Luminescence of ion-pair and spin-excited states of I2 in solid xenon

We report UV and visible mol. ion-pair emission upon 193 nm excitation of I2 in solid xenon. By comparison to mol. emission obsd. in Kr matrixes, it is assigned to the d(2u)->2g (I*+I) and d(2u)->2g (I+I) transitions. The solvation energy of this charge transfer state is surprisingly small, and the fluorescence is efficiently quenched when the sample temp. is raised. Population may partially flow into valence states correlating to the I*+I* asymptotes. In contrast to all lighter matrixes, I*+I*->I2 luminescence is obsd. upon excitation in the region of ion-pair absorption in solid Xe. [on SciFinder (R)]