Surface photochemistry: the organic charge-transfer complexes on silica

Surface effect on processes of intermolecular interaction has been studied. With this end in view, bimolecular donor-aceptor pairs forming the charge-transfer complexes in the ground and excited (exciplex) states in silica surface layer are used. Steady-state and time-resolved fluorescence measurements were performed at 293 K and 77 K. It has been established that stability of the electron-donor-acceptor complexes and their spectroscopic behaviour are governed by the adsorption mechanism of components of the complexes, by the distribution of molecules in surface layer as well as the concentration of adsorbates.