COMMENT ON THE NATURE OF THE LIGHT-INDUCED METASTABLE STATES IN NITROPRUSSIDES

The extremely long lifetimes (τ &> 107 s at T = 0 K) of light-induced metastable states (MS) in nitroprussides provide a key to understanding their nature. Both radiative (kr) and nonradiative (knr) relaxation rates must be extremely small. In order for knr (T = 0 K) to be smaller than 10-7 s-1, there has to be a substantial distortion of the MS with respect to the ground state (GS). The small kr (T = 0 K) < 10-7 s-1 is the result of the large displacement of GS↔MS potentials on the one hand, and a very small oscillator strength of the GS&.harr;MS transition on the other hand. © 1990.