Phosphorescence: Photoreversible On–Off Recording of Persistent Room‐Temperature Phosphorescence (Advanced Optical Materials 12/2015)

A host–guest–guest material is prepared by S. Hirata and co-workers on page 1726 to demonstrate the photoreversible on–off recording of persistent room-temperature phosphorescence from the phosphorescent guest. The reversible photocyclization and decyclization of the photochromic guest allow and prevent dipole–dipole energy transfer from the phosphorescent guest to the photochromic guest, respectively. The occurrence and lack of energy transfer trigger the deactivation and activation of persistent room temperature phosphorescence, respectively.