On the photochemistry of impurity molecules in a photonic crystal

The behavior of the quantum yield of the photochemical processes occurring in polyatomic impurity molecules incorporated in a photonic crystal and its dependence on the relative position of the band gaps of the crystal and the energy of low-lying excited states of a molecule are discussed. Provided that the energy of the low-lying singlet photoactive state of a molecule is in the crystal band gap, an increase in the quantum yield of a photochemical reaction over its value in standard solutions must be observed. The processes of isomerization, dissociation, proton transfer, and oxidation are among these reactions. Examples of systems where the manifestation of this effect should be expected are given. The reactions that occur in the low-lying and high-lying triplet states, which are initiated by two-phonon excitation, and those sensitized upon the intermolecular transfer of electronic excitation energy are discussed. © 2009 Pleiades Publishing, Ltd.