Chiral Carbon Nanorings: Synthesis, Properties and Hierarchical Self‐assembly of Chiral Ternary Complexes Featuring a Narcissistic Chiral Self‐Recognition for Chiral Amines

We report the synthesis and chiroptical properties of novel chiral carbon nanorings Sp‐/Rp‐[12]PCPP containing a planar chiral [2.2]PCP unit, and demonstrate that Sp‐/Rp‐[12]PCPP can not only host crown ether 18‐Crown‐6 to form ring‐in‐ring complexes with a binding constant 3.35×103 M−1, but also accommodate the complexes of 18‐Crown‐6 and S/R‐protonated amines to form homochiral S@Sp‐/R@Rp‐ and heterochiral S@Rp‐/R@Sp‐ ternary complexes, displaying significantly larger binding constants of up to 3.31×105 M−1 depending on the chiral guests. Importantly, homochiral S@Sp‐/R@Rp‐ ternary complexes exhibit an enhanced CD signal, while the heterochiral S@Rp‐/R@Sp‐ ones have a constant CD signal compared with the chiral carbon nanorings, respectively, which suggests that homochiral S@Sp‐/R@Rp‐ ternary complexes display a highly narcissistic chiral self‐recognition for S/R‐protonated chiral amines, respectively. Finally, the chiral ternary complexes can be further applied to determine the ee values of chiral guests. The findings highlight a new application of carbon nanorings in supramolecular sensors, beyond the common recognition of π‐conjugated molecules. Chiral carbon nanorings with excellent photophysical and chiroptical properties have been synthesized. Importantly, Chiral ternary complexes, consisted of chiral carbon nanorings, 18‐Crown‐6 and protonated chiral amines, display excellent narcissistic chiral self‐recognition for protonated chiral amines.