Manipulating noncovalent conformational lock via side-chain engineering for luminescence at aggregate level

The unfavorable photochemical processes at the molecular level have become a bar-rier limiting the use of aromatic amides as high-performance luminescent materials.Herein,we propose a reliable strategy for manipulating noncovalent conformational lock(NCL)via side-chain engineering to burst out eye-catching luminescence at the aggregate level.Contrary to the invisible emission in dilute solutions,dyad OO with a three-centered H-bond gave the wondrous crystallization-induced emis-sion with a quantum yield of 66.8%and clusterization-triggered emission,which were much brighter than those of isomers.Theoretical calculations demonstrate that crystallization-induced planarized intramolecular charge transfer(PICT),con-formation rigidification,and through-space conjugation(TSC)are responsible for aggregate-state luminescence.Robust NCL composed of intramolecular N-H⋅⋅⋅Ointeractions could boost molecular rigidity and planarity,thus greatly facilitating PICT and TSC.This study would inspire researchers to design efficient luminescent materials at the aggregate level via rational conformational control.