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

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- horizontal ellipsis pi 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.