Generating Circularly Polarized Light from Clustering‐Triggered Emission Using Solid Phase Molecular Self-Assembly

Abstract

Clustering-triggered emission (CTE) has displayed promising abilities in bioimaging, chemical sensing, and multicolor luminescence. However, it remains absent in the field of circularly polarized emission (CPL) due to the difficulties in well-aligning the nonconventional luminogens. We report the first case of CPL generated with CTE using the solid phase molecular self-assembly(SPMSA) of poly-L-lysine(PLL) and sodium oleate (OL). Under mechanical pressure, the electrostatic complex of PLL/OL form supramolecular film in which the OL ions self-assemble into lamellar mesophases bridged by the PLL chains. Since the OL mesophases are very alike giant 2D rigid supramolecular polymers with well-defined surface charge distribution, the PLL chains are forced to fold regularly as a requirement of optimal electrostatic interaction. Further facilitated by hydrogen bonding, the O and N atoms that form through space conjugation aligned orderly on the 2D surface, leading to CTE-based CPL. The CTE-based CPL is in analogy with conventional emission, which is capable to transfer its energy to a donor via a FRET process, making it possible to develop environmental friendly and economic CPL from sustained and renewable materials.