Reversibly Photoswitchable Supramolecular Assembly and Its Application as a Photoerasable Fluorescent Ink

A photoswitchable supramolecular assembly can efficiently and reversibly switch on/off the luminescence of the [Ru(bpy)3]2+ center upon irradiation by light with different wavelengths in solution and the solid state. The assembly possesses reversible photoisomerization and a high Förster resonance energy transfer efficiency, and when used as an ink it can be reversibly and repeatedly erased and recovered by altering the wavelength of irradiation light.