A 2,2′-bis(benzimidazolium)-dibenzo[24]crown[8] rigid pseudorotaxane system

Pseudorotaxanes from the self-assembly of simple 2,2′-bis(benzimidazolium) dications and DB24C8 is a first of its kind when a protonated bis(benzimidazole) without a methylene spacer between the two benzimidazolium units (a very rigid axle without flexibility) thread DB24C8 as a result of H-bonding interactions. The formation of these pseudorotaxanes was first ascertained from 1H NMR spectroscopy and later corroborated by HRMS, 2D NMR and finally supported by rigorous DFT calculations.