Dramatic Differences in Aggregation-Induced Emission and Supramolecular Polymerizability of Tetraphenylethene-Based Stereoisomers

Geometric (Z)- and (E)-isomers play important but different roles in life and material science. The design of new (Z)-/(E)- isomers and study of their properties, behaviors, and interactions are crucially important in molecular engineering. However, difficulties with their separation and structure confirmation limit their structural diversity and functionality in scope. In the work described herein, we successfully synthesized pure isomers of ureido­pyrimid­inone-functionalized tetra­phenyl­ethenes ((Z)-TPE-UPy and (E)-TPE-UPy), featuring both the aggregation-induced emission characteristic of tetra­phenyl­ethene and the supra­molecular polymer­izability of ureido­pyrimid­inone. Their structures were confirmed by 2D COSY and NOESY NMR spectroscopies. The two isomers show distinct fluorescence in the aggregate state: (Z)-TPE-UPy exhibits green emission, while its (E)-counterpart is blue-emitting. The cavity formed by the two ureido­pyrimid­inone groups of (Z)-TPE-UPy makes it suitable for Hg2+ detection, and the high-molecular-weight polymers prepared from (E)-TPE-UPy can be used to fabricate highly fluorescent fibers and 2D/3D photo­patterns from their chloroform solutions.