Chiral macrocycles forming high-affinity host-guest homoternary complexes for chiral discrimination and amplified circularly polarized luminescence.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41188221.
- Also identified by DOI 10.1038/s41467-025-64739-7 and PMC identifier 12586481.
- Licence recorded as CC BY-NC-ND.
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Abstract
The development of macrocyclic hosts with high-affinity 1:2 recognition capabilities is crucial for advancing supramolecular chemistry and its applications. While cucurbit[8]uril (CB[8]) has long been recognized for its unparallel 1:2 binding affinity, its limitations-including poor solubility, difficulty to modify and lack of optical activity-have hindered broader utilization. Here, we introduce a class of enantiopure chiral macrocycles, RRRR- or SSSS-corral[4]BINOL (C[4]Bs), which exhibit remarkable 1:2 recognition properties in water that are comparable or even surpass CB[8]. Using UV-Vis, fluorometric, and isothermal titration calorimetry (ITC), we demonstrate that C[4]Bs form stable homoternary complexes with 11 singly positively charged planar aromatic guests, with binding affinities up to 10<sup>17 </sup>M<sup>-2</sup>. These ultrahigh affinities make C[4]Bs versatile alternatives to CB[8], offering advantages such as superior water-solubility, ease of structural modification, and strong fluorescence. Furthermore, the unique chiral nature of C[4]Bs enables efficient fluorescent discrimination of chiral substrates and chirality transfer to non-chiral dyes, resulting in strong circularly polarized luminescence (CPL) with |g<sub>lum</sub> | values up to 1.1 ×10<sup>-2</sup>. This study establishes C[4]Bs not only as powerful hosts for aqueous-phase supramolecular complexation but also as a promising platform for developing chiral functional materials.