Two new homotritopic guests based on tris(benz)imidazolium salts with adamantane binding sites were prepared. NMR and calorimetric titration experiments revealed that each of the three sites independently binds bcyclodextrin (b-CD) or cucurbit[7]uril (CB7) units to form binary host-guest complexes with 1:3 stoichiometry. The association constants for the single binding site for b-CD and CB7 were determined using titration calorimetry and are in the order of 10 5 and 10 9-10 dm 3 mol -1 , respectively. In addition, both guests were able to form ternary systems with b-CD and CB7 in ratios of 1:1:2 and 1:2:1, respectively.

Stilbene derivatives are well‐recognised substructures of molecular switches based on photochemically and/or thermally induced (E)/(Z) isomerisation. We combined a stilbene motif with two benzimidazolium arms to prepare new sorts of supramolecular building blocks and examined their binding properties towards cucurbit[n]urils (n=7, 8) and cyclodextrins (β‐CD, γ‐CD) in water. Based on the 1H NMR data and molecular dynamics simulations, we found that two distinct complexes with different stoichiometry, i. e., guest@β‐CD and guest@β‐CD2, coexist in equilibrium in a water solution of the (Z)‐stilbene‐based guests. We also demonstrated that the bis(benzimidazolio)stilbene guests can be transformed from the (E) into the (Z) form via UV irradiation and back via thermal treatment in DMSO.