Cucurbit[8]Uril Achieved Single-Molecule Chiral Transfer to Supramolecular Circularly Polarized Luminescence.

Herein, cascaded supramolecular assembly was constructed from phenylalanine-modified biphenyl-pyridine derivatives (L/D-FPy), cucurbit[8]uril (CB[8]), and amphipathic sulfonatocalix[4]arene (SC4AD), which not only exhibits cascaded energy transfer and chiral transfer but also achieves amplified circularly polarized luminescence (CPL). The experimental results demonstrate that L/D-FPy and SC4AD directly assemble through electrostatic interactions to form particles, where the luminescence intensity and quantum yield (QY) were significantly enhanced by 140 and 8 times, respectively. The positively charged L/D-FPy and CB[8] combine to form a 1:1 stoichiometric supramolecular assembly. Compared with the L/D-FPy@SC4AD assembly, the system with added SC4AD in the presence of CB[8] exhibited a 2.5‑fold enhancement in luminescence intensity and QY, and also amplification of chirality. Taking advantage of the energy transfer and chiral transfer, L/D-FPy⊂CB[8]@SC4AD co-assembly with the achiral dyes benzothiadiazole (DBT) and Nile red (NR), and the polymer polyvinyl alcohol (PVA), markedly increased the CPL. The luminescence asymmetry factor values for L/D-FPy⊂CB[8]@SC4AD:NR were estimated to be-4.05 × 10-3 and+4.32 × 10-3 in solid film, respectively. Therefore, the present research provides an approach to construct multicolor CPL supramolecular assembly, which is not only applied to digital anti-counterfeiting but also to chiral logic gates.