Abstract:

In this paper, the host-guest relationship between a general cucurbit[n=7]uril(Q[7]) or a new ellipsoid-hostsymmetric tetramethyl-cucurbituril(TMeQ[6]) with hydrochloride salts of 4,4′-dipyridyl(44) or N,N′-dimethyl-4,4′-dipyridyl(dm44) was  examined for confirming the interaction between cucurbituril(Q[6]) and these guests.  The experimental results revealed that Q[7] included the 4,4′-dipyridyl part of this kind of guests which were inclined in the cavity of Q[7].  The results based on  ¹H NMR technique, cyclic voltammetric method and UV absorption spectrophotometric measurement revealed that strong interaction was existed between TMeQ[6] and  guest 44 or dm44 and a one-dimensional assembled superamolecular could be formed.  1H NMR technique and cyclic voltammetric method showed  no obvious interaction between Q[6] with the guest 44 and its derivates, however, UV absorption spectrophotometric measurements revealed that kind of interaction of them did occur, comparing the structural characteristic of Q[6] to TMeQ[6], a one-dimensional assembled superamolecular could be also formed between Q[6] and guest 44 and its derivates.

Key words: Cucurbit[n=6,7]uril;  Symmetric tetramethyl cucurbituril;  4,4′Dipyridyl hydrochloride salt and its derivates;  Interaction model