A hetero[6]rotaxane bearing three different kinds of macrocycle is designed and successfully synthesized through a one-pot “click” reaction by employing a facile and efficient integrative self-sorting principle.

Well-defined supramolecular helical nanofibers have been constructed by a rationally designed achiral monomer in aqueous solution based on the 1:2 host-guest combination between cucurbit[8]uril and a 4,4'-bipyridin-1-ium chloride (BPY ) salt derivative. The formed nanostructures could be adjusted by varying the concentration of monomer from helical nanofibers to a pH-responsive hydrogel.

Ap H-responsive double-lasso macrocycle has been successfully obtained directly from a[ c2]daisyc hain rotaxane via ap hotodimerization reaction of two terminal coumarin ligands. The size of the double-lasso macrocycle could be tuned by acid/base stimuli with the reversible muscle-likee xtension/contraction of the [c2]daisyc hain unit.Scheme1.Synthetic route to double-lasso macrocycle 1 containing[ c2]daisy chain rotaxane. The coumarin unit formed after photodimerization has four isomerso wing to cycloaddition, and only one of them is shownh ere.

The structural complexity of mechanically interlocked molecules are very attractive to chemists owing to the challenges they present. In this article, novel mechanically interlocked molecules with a daisy-chain-containing hetero[4]rotaxane motif were efficiently synthesized. In addition, a novel integrative self-sorting strategy is demonstrated, involving an ABB-type (A for host, dibenzo-24-crown-8 (DB24C8), and B for guest, ammonium salt sites) monomer and a macrocycle host, benzo-21-crown-7 (B21C7), in which the assembled species in hydrogen-bonding-supported solvent only includes a novel daisy-chain-containing hetero[4]pseudorotaxane. The found self-sorting process involves the integrative recognition between B21C7 macrocycles and carefully designed components simultaneously containing two types of secondary ammonium ions and a host molecule, DB24C8 crown ether. The self-sorting strategy is integrative to undertake self-recognition behavior to form one single species of pseudorotaxane compared with the previous report. This self-sorting system can be used for the efficient one-pot synthesis of a daisy-chain-containing hetero[4]rotaxane in a good yield. The structure of hetero[4]rotaxane was confirmed by H NMR spectroscopy and high-resolution electrospray ionization (HR-ESI) mass spectrometry.