Macrocyclic shape-persistency of cyclo[6]aramide results in enhanced multipoint recognition for the highly efficient template-directed synthesis of rotaxanes

Abstract

The importance of macrocyclic shape-persistency in novel host–guest systems for the highly efficient template-directed synthesis of rotaxanes has been revealed.

A nitrogen-rich covalent organic framework for simultaneous dynamic capture of iodine and methyl iodide

“…First of all, the densely functionalized bipyridine building blocks are expected to interact with the elemental iodine molecule through the electronpair effect with enhanced binding affinity and to act as the substrate of the methylation reaction for the immobilization of methyl iodide. 17,29 Second, the fully conjugated and highly hydrophobic framework structure of SCU-COF-2 endows it with decent irradiation, moisture, and thermal stability required for the extreme operating condition in UNF reprocessing. 1,4 Excellent iodine capture capabilities were demonstrated by breakthrough experiments under high humidity and elevated temperature.…”

Cavity-containing aromatic oligoamide foldamers and macrocycles: progress and future perspectives

“…Upon mixing macrocycle 17 with bipyridinium cations, a color change from clear to light yellow was observed, indicative of complex formation. 38 UV-Vis and 1 H NMR titrations confirmed the presence of a 2 : 1 complex consisting of two macrocyclic molecules and one cationic guest. Association constants were determined by nonlinear fitting of the titration curves and were found to be K 1 = 3.49 × 10 7 M −1 and K 2 = 1.09 × 10 6 M −1 with K total = 3.80 × 10 13 M −2 in acetone, revealing exceptionally strong binding affinity.…”

A Dynamic Hydrogen‐Bonded Azo‐Macrocycle for Precisely Photo‐Controlled Molecular Encapsulation and Release

“…Analysis of single crystal structure of 1 b (Figures a and S72 in the Supporting Information), which shares the same backbone as 1 a but bears shorter side chains instead, reveals desired E configuration for both azo groups, and a cavity that measures 8.3 Å between the two diagonally arranged oxygen atoms. Given the fact that cyclo[6]aramide (8.17 Å) in our prior work is capable of binding bipyridinium salts, we envisioned that this H‐bonded macrocycle can also strongly bind a guest such as a bipyridinium cation (4.3 Å).…”