This dissertation describes the first intramolecularly activated precipitons. The isomerization process is induced by intramolecular triplet energy transfer from a covalently attached sensitizer. The intramolecular sensitization leads to a more rapid isomerization than can be achieved by intermolecular sensitization at accessible concentrations. Two different types of intramolecularly sensitized precipitons were investigated. The first precipiton receives intramolecular sensitization from a covalently attached metal complex (Ru(bpy)3Cl2). It was used in a model study for the sequestration of metal contaminants. The second precipiton receives intramolecular sensitization from a covalently attached organic compound (benzil). The preparation, photophysical properties, and photoisomerization kinetics of these precipitons, as well as the precipitation event, are discussed