Supramolecular Self-Assembly between Teteamethyl Cucurbit[6] uril and Alkyl Viologens

Three symmetric viologen derivatives bearing aliphatic substituents of variable length were employed as guests, and the supramolecular self-assembly between teteamethyl cucurbit[6] uril ( TMeQ[6]) and these viologen derivatives guests has been studied by H-1 NMR spectroscopy, electronic absorption spectroscopy, isothermal titration calorimetry, mass spectrometry and X-ray diffraction methods in details. The experimental results revealed that there are similar interaction models between TMeQ[6] and three viologens guest, the alkyl chains of the guests are located inside the cavity of the TMeQ[6] host, whereas the 4,4'-dipyridyl moieties of the guests remain outside of the portal, forming a 2:1 host-guest inclusion complex.