An Interlocked Figure-of-Eight Molecular Shuttle

Here is reported the synthesis and characterization of an interlocked figure-of-eight rotaxane molecular shuttle from a dibenzo-24-crown-8 (DB24C8) derivative. This latter bears two molecular chains, whose extremities are able to react together by click chemistry. One of the two substituting chain holds an ammonium function aimed at driving the self-entanglement through the complexation of the DB24C8 moiety. In the targeted figure-of-eight rotaxane, shuttling of the DB24C8 along the threaded axle from the best ammonium station to the weaker binding site triazolium was performed through deprotonation or deprotonation-then-carbamoylation of the ammonium. This way, two discrete co-conformational states were obtained, in which the folding and size of the two loops could be changed.

Automated summary

The synthesis and characterization of a complex interlocked figure-of-eight rotaxane molecular shuttle are reported. The shuttle contains two molecular chains, which can react together through click chemistry. The self-entanglement of the shuttle is driven by the complexation of an ammonium function with a dibenzo-24-crown-8 moiety. The shuttling of the shuttle along the threaded axle is achieved by deprotonation or deprotonation-then-carbamoylation of the ammonium, resulting in two discrete co-conformational states with adjustable folding and size of the loops.