193 NM PHOTODYNAMICS OF NO IN RARE-GAS MATRICES - FLUORESCENCE, THERMOLUMINESCENCE, AND PHOTODISSOCIATION

193 nm excited time gated emission spectra of a NO monomer isolated in Ar, Kr, and Xe matrices are presented. In the Ar matrix a (II)-I-4 -- > X (II)-I-2, B (II)-I-2 -->X (II)-I-2, and A (2)Sigma --> X (II)-I-2 band systems are completely separable. In solid Kr, both B (II)-I-2 -- > X (II)-I-2 and A (2)Sigma --> X (II)-I-2 appear promptly from the la ser pulse, and in the Xe matrix only Rydberg A (2)Sigma --> X (II)-I-2 fluorescence is observed. Prolonged photolysis at 193 nm yields elect ron paramagnetic resonance signals attributed to isolated S-4 nitrogen atoms. This is the first observation of condensed phase photodissocia tion of NO. Annealing of the extensively irradiated Ar matrix produces strong a (II)-I-4 --> X (II)-I-2 and B (II)-I-2 --> X (II)-I-2 thermo luminescence emissions due to N(S-4) + O(P-3) recombination. In the Kr matrix thermoluminescence is entirely due to a (II)-I-4 --> X (II)-I- 2 transition. No thermoluminescence is observed in Xe. Thermoluminesce nce is ascribed to short-range trapping of N and O fragments, and well separated atoms do not have significant contribution to recombination . (C) 1998 American Institute of Physics.