Pseudorotaxane complexes between viologen vinylogues and cucurbit[7]uril: New prototype of photocontrolled molecular machine

Dibetaines of unsaturated viologen analogues that form supramolecular complexes with cucurbit[7]uril were synthesized. The pseudorotaxane structure and stability of the complexes were established by UV/Vis and 1H NMR spectroscopy and by X-ray diffraction analysis. Complexes of this structure are prototypes of a light-controlled molecular machine.