In aqueous solution, dibenzylimidazolium bromide salts form dimeric assemblies by T-stacking between an acidic proton of the imidazolium and the benzyl aromatic ring of another cation. This dimeric association can be disturbed by the addition of native cyclodextrins. The control of the majority species in solution can be made by the judicious choice of cyclodextrin concentration and its macrocycle size. The dimer is complexed directly by beta-cyclodextrin, whereas in the presence of alpha-cyclodextrin, the dimer is dissociated to form a 1: 1 inclusion complex; at higher concentration, this 1:1 complex can dimerize.