Stabilization of Optical Molecules Using Dendritic Boxes against Singlet Oxygen in Photobleaching

ABSTRACTThe stabilizing effect of dendritic boxes (DBoxes) as a means to protect against photo- degradation of encapsulated dye molecules was experimentally investigated. We focused on photoinduced oxidation and studied the ability of DBoxes to protect dyes inside them from reactive singlet oxygen. Rubrene was captured in a DBox, and then the box was closed at the surface by other stable molecules. A singlet oxygen generator was added to a Rubrene solution to exaggerate photo-oxidation in the complicated total-photodegradation process, and then the solution was exposed to a laser beam to generate singlet oxygen. Bleaching of the encapsulated Rubrene in a DBox was 50 times slower than that of Rubrene alone. We also compared the dependence of surface molecules of a DBox with other kinds of molecules that have different efficiencies of quenching singlet oxygen. Further improved stability was observed by attaching singlet-oxygen-quencher molecules on the DBox surface.