Divalent Pseudorotaxane with Polarized Plug-Socket and Padlock Functions.

A dual-pore structured host composed of one 24-crown-8 and one 34-crown-10, and a "U"-shaped guest consisting of two different recognition units, one dibenzylammonium and one viologen, were synthesized and bound 1:1 into a divalent pseudorotaxane P1. P1 can mimic the inserting and pulling out functions of a polarized plug-socket system under solvent driven stimulus and can also realize the locking and unlocking actions of a padlock under pH stimulus.