Control of Aggregation-Induced Emission from a Tetraphenylethene Derivative through the Components in the Co-crystal

Abstract

We aim to control the photoluminescence property of co-crystals derived from an aggregation-induced emission luminogen (AIEgen) through other components in the co-crystal. For this purpose, we prepared co-crystals of a typical AIEgen, tetraphenylethene having four hydroxy groups (THPE), and hydrogen-bond acceptors (HBAs) containing nitrogen atoms. The crystallographic study showed that the hydrogen-bonding pattern and inclusion of crystallization solvents are significantly influenced by the employed HBA, depending on the size, position of nitrogen atoms, and basicity of the HBA, thanks to the moderate hydrogen-bonding ability of THPE. The photoluminescence properties of the co-crystals are governed by the employed HBA, and thus, co-crystals derived from imidazole derivatives or 1,4-diazabicyclo[2.2.2]octane exhibit intense photoluminescence, while those from pyridine derivatives and an electron-deficient imidazole derivative do not show any photoluminescence. The involvement of photoinduced electron trans...