Stable pillar[5]arene-based pseudo[1]rotaxanes formed in polar solution

Mono-alkyl-functionalized pillar[5]arenes P1, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[1]rotaxane was formed by the self-complexation from P1 or P2, whereas, concentration-dependent pseudorotaxane structures were generated by P3. Moreover, the obtained pseudo[1]rotaxanes exhibited a dynamic fast assembly process upon adding NaBF4, resulting in the formation of Na+-induced pseudorotaxanes.