title: Study of the counter anions in the host-guest chemistry of cucurbit[8]uril and 1-ethyl-1'-benzyl-4,4'-bipyridinium.
abstract: A series of 1-ethyl-1'-benzyl-4,4'-bipyridinium compounds with different counter anions (BEV-X2, where the X is Cl, Br, I, PF6, ClO4) were synthesized. By using of NMR, MS, electrochemistry, Na2S2O4-induced redox chemistry, and UV-Vis, the role of the different counter anions in the host-guest chemistry of cucurbit[8]uril (CB[8]) was studied for the first time. The result demonstrated that BEV-X2 can form a 1 : 1 host-guest complex with CB[8] in water. Theoretical calculation further suggested that the viologen region was threaded through the cavity of CB[8], while the corresponding counter anions were located outside the cavity. Some difference can be observed on UV-Vis titration and Na2S2O4-induced redox chemistry, which showed that the counter anions have some effect on the host-guest chemistry. All these provide new insights into CB[8] host-guest system.
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Hailong
authors.initials: H
authors.lastname: Ji
authors.forename: Fengyu
authors.initials: F
authors.lastname: Liu
authors.forename: Shiguo
authors.initials: S
authors.lastname: Sun
mesh_terms: D000838:Anions / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D011726:Pyridinium Compounds / Q000737:chemistry*
chemical_list: D000838:Anions; D011726:Pyridinium Compounds