Assembly-disassembly switching of chiral sheet assembly for controlled circularly polarized luminescence

Although substantial advances have been made regarding synthetic chiral assemblies, obtaining the two-dimensional (2D) system with a sophisticated supramolecular chirality remains challenging. Herein, we report the switchable supramolecular chiral 2D materials via donor-acceptor interaction between a pyrene amphiphile and 7,7,8,8-tetracyanoquinodimethane (TCNQ). The resulting supramolecular chiral sheets spontaneously disassemble when TCNQ is irreversibly photo-reduced to its anion. Subsequent additions of TCNQ drive the disassembled molecules to repeatedly form optically active sheet structures, demonstrating that the assembled materials exist transiently only while TCNQ is supplied. The chiral sheets emit intense circularly polarized light with a large luminescence dissymmetric factor (g(lum)).