Circularly-polarized luminescence (CPL) has received new attention on the rise of applications to generate devices and biologically active probes. These applications require fluorophores that are not only chiral but also provide strong fluorescence intensity in aggregated state. Thus, a new research branch has opened up a few years ago, which allows CPL-active fluorophores to be emissive in aggregated-state. As a result, reports on the combination of the CPL property with the aggregation-induced emission (AIE) phenomenon have emerged. Herein the early design principles that have been reported until now to generate CPL-active AIE-active fluorophores (AIEgens) are summarized. In this regard the alignment of monomeric emitters in a chiral fashion, either in supramolecules, polymers or liquid crystals has been proven to be a successful approach. Additionally, first reports have appeared that demonstrate how to tackle the daunting task to furnish individual CPL-active AIEgens.

Chiral recognition as well as chirality transfer in supramolecular self-assembly and on-surface coordination is studied for the enantiopure 6,13-dicyano[7]helicene building block. It is remarkable that, with this helical molecule, both H-bonded chains and metal-coordinated chains can be formed on the same substrate, thereby allowing for a direct comparison of the chain bonding motifs and their effects on the self-assembly in experiment and theory. Conformational flexure and both adsorbate/adsorbent and intermolecular interactions can be identified as factors influencing the chiral recognition at the binding site. The observed H-bonded chains are chiral, however, the overall appearance of Cu-coordinated chains is no longer chiral. The study was performed via scanning tunneling microscopy, X-ray-photoelectron spectroscopy and density functional theory calculations. We show a significant influence of the molecular flexibility and the type of bonding motif on the chirality transfer in the 1D self-assembly.