ABSTRACT
This book is on synthetic organic photochemistry. With emphasis on ‘‘synthetic.’’
Considering only the electronically excited states of organic molecules relevant for photochemistry, essentially the first excited singlet and triplet states (in rare cases, contrary to the expectations of the Kasha rule, also the second excited states), the reactivity options are triplicated when compared to ground-state reactivity. Furthermore, photoinduced electron transfer (PET) is capable of activating organic substrates by one-electron oxidation and/or reduction and thus, in optimal cases, singlet excited states are available to direct photon excitation, triplet states by triplet sensitization (or via rapid and efficient ISC from the corresponding excited singlet), radical anions by PET with an appropriate donor (e.g., an amine or thioether), and radical cations by PET with an appropriate acceptor (e.g., cyanoaromatics or pyrylium salts). Reactivity options are thus quintupled when compared to ground-state reactivity.
