Viologen-Based Rotaxanes from Dibenzo-30-crown-10

Three [2]­rotaxanes (4, 7, and 12) and one [3]­rotaxane (8) were synthesized based on the dibenzo-30-crown-10/viologen binding motif. To the best of our knowledge, these are the first rotaxanes formed from dibenzo-30-crown-10 and viologens. The rotaxanes were all characterized by 1H NMR, 13C NMR, and HRMS. An X-ray crystal structure of one of the [2]­rotaxanes (7) was obtained. This work demonstrates for the first time that dibenzo-30-crown-10 does form pseudorotaxane complexes with viologens in solution.