Photochemical switching of luminescence and singlet oxygen generation by chemical signal communication

摘要

Photoluminescence in the far red spectral region and photosensitised generation of singlet oxygen, with associated near-IR emission, are reversibly controlled by near-UV or violet light in a communicating ensemble of molecular switches.rnPhotochemical switches are molecular or supramolecular species in which properties or functions can be switched on and off by light. The design and preparation of molecule-based systems in which optical outputs can be modulated reversibly in response to optical inputs is a scientifically stimulating objective, with potential outcomes in fields such as materials science and information and communication technology.rnAs shown by biological structures, the type and utility of the functions that can be obtained with photochemical switches depend on the degree of complexity and organisation of the chemical species that receive and process the photons. In the frame of artificial systems, one approach is that of linking together, either by weak interactions or covalent bonds, a discrete number of molecular components. Along this line, a large number of multicomponent (supramolecular) systems exhibiting photoinduced functions such as light harvesting, charge separation, catalysis, control of acid-base properties, drug delivery, logic operations, and molecular mechanical motions, have been investigated.