Modes of binding interaction between viologen guests and the Cucurbit[7]uril host

摘要

Host-guest interactions between cucubit[7]uril ((CB7)and a series of dialkyl-4,4'-bipyridinium (viologen)dicationic guests were investigated by NMR spectroscopy.CB7 includes the aromatic nucleus of short chain viologens,but the mode of interaction is fifferent with longer chain viologens due to the favorable hydrophobic interactions between the terminal alkyl substituents and the inner cavity of the host.A new pseudorotaxane was designed and synthesized on the basis of viologen-CB7 binding interactions.