Application of time-resolved resonance Raman spectroscopy to the study of rapid intramolecular radiationless transitions

It is shown that the decay rate γ₂ of the excited state of a molecule can be determined by measuring the decrease of the resonance Raman intensity on a time scale much longer than γ^?1₂, provided that the time needed for repopulation of the ground state, following rapid intramolecular radiationless transitions from the excited state to a molecular quasicontinuum, is itself much longer than γ^?1₂. Thus, it should be possible to avoid the use of ultrashort pulses in the study of very fast intramolecular decay process.