Self-Assembly of Chiral Metal–Organic Helicates and Enhancement of Chiroptical Properties via Subcomponent Modulation

We report three chiral metal-organic helicates (MOHs) constructed through the self-assembly of anthracene-based aldehyde precursors, chiral amino precursors with different groups ((<i>R/S</i>)-1-phenylethanamine, (<i>R/S</i>)-1-(1-naphthyl)ethylamine, or (<i>R/S</i>)-1-(2-naphthyl)ethylamine), and Zn²⁺ ions. These helicates exhibit a chiral Zn₂L₃ architecture, which is confirmed by mass spectrometry, NMR spectroscopy, and theoretical calculations. Our work indicates that the conjugated extension and spatial arrangement of subcomponents can enhance the exciton coupling effect, thereby increasing the absorption asymmetry factor (<i>g</i>_abs) and optimizing the chiroptical properties of MOHs. Compared with free ligands, the <i>g</i>_abs values can be enhanced by up to 48-fold. This work provides valuable insights for designing tunable materials with tailored highly active chiroptical properties.