Two Calix[3]Phenothiazine‐Based Amorphous Pure Organic Room‐Temperature Phosphorescent Supramolecules Mediated by Guest

Abstract Herein, two kinds of amorphous solid‐state supramolecular systems with purely organic room temperature phosphorescence (RTP) from calix[3]phenothiazine ( C[3]Pz ) activated by 1,2‐/1,3‐dicyanobenzene ( 1,2‐/1,3‐DCB ) are reported. Different from macrocycle‐confined guest phosphorescence emission, RTP of these two amorphous solid‐state supramolecular systems is entirely from the 1,2‐/1,3‐DCB rivets C[3]Pz cavity to form dense supramolecular complex through CH … π interactions, leading to two different phosphorescence emissions at 566/524 nm under 430 nm excitation, respectively. Although C[3]Pz shows a regular arrangement in the crystal, the vibration dissipation of the benzene ring results in C[3]Pz emitting only fluorescence at 508 nm at room temperature. 1,2‐DCB and 1,3‐DCB can act as molecular rivets to fix the C[3]Pz to inhibit molecular vibration so as to reduce nonradiative relaxation, which enables C[3]Pz to achieve effective RTP emission with 20.8–36.8% quantum yields. This kind of guest‐activated host RTP, which is fairly rare in supramolecular systems, is successfully used for color QR codes and information encryption.