Electronic and Molecular Motions in Silica-Material Hosts

Abstract This chapter deals with photoinduced charge-transfer reactions occurring for guests within or attached to silica-material hosts (SMHs). It focuses on the effect exerted by the hosting environment on the spectroscopic and photodynamical behavior of the interacting guests. It describes the fundamental processes after photoirradiation of trapped guests like charge–electron-transfer reactions, and the subsequent formation of charge-transfer complexes and long-lived charge-separated states. These processes are unraveled by the combined use of steady state—UV–vis absorption and emission spectroscopies—and time resolved-flash photolysis, time-correlated single-photon counting (TCSPC), femtosecond (fs) up-conversion, and transient absorption spectroscopies techniques. This chapter resumes some of the most representative works performed during the last two decades, opening a window to the design and fabrication of modern composites having applicability in fields such as photocatalysis and photonics.