Ultrafast nonradiative transitions between higher excited states in organic molecules

Ultrafast nonradiative transitions between electronic levels of aromatic and dye molecules, competing with fast photochemical reactions (e.g., electron or proton transfer, photoisomerisation, etc.), are considered. The results of determination of the rate constants for nonradiative transitions between higher excited singlet and triplet states using different methods are summarised. The experimental data are interpreted in terms of the exchange-resonance theory of nonradiative transitions. The bibliography includes 189 references.