Amorphous pure organic phosphorescent host-guest complexes with ultralong phosphorescence lifetime and high-temperature tolerance

It is still a meaningful and challenging task to prepare ultralong-lived (phosphorescence lifetime τP ˃ 100 ms) pure organic phosphorescence materials emitting at room temperature, let alone at high temperature (e.g., 100 °C). Herein, 1-methyl-4-phenylpyridin-1-ium salts (PMX, X = Cl, PF6, Br and I) without afterglow are tightly encapsulated into the cavity of phCB[6] (a CB[6] derivative) to form amorphous ultralong-lived host-guest phosphorescence complexes PMCl/phCB[6] (1.57 s), PMPF6/phCB[6] (1.35 s) and PMBr/phCB[6] (0.51 s) with green afterglow lasting for 9–10 s under ambient conditions. More importantly, the green phosphorescence is still visible to the naked eyes even at 100 °C, exhibiting excellent high-temperature tolerance. Such an encapsulation strategy for obtaining high-temperature phosphorescent materials has not been reported yet and would pave a new road for its further applications.