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By using the method of building blocks, the dodecamethycucurbit[6]uril Me12Q[6] was synthesized and its structure was characterized by multiple techniques. The binding interactions between Me12Q[6]...

In the present study, the coordination and supramolecular self-assemblies of a series of alkali and alkaline earth metal ions to cucurbit[5]uril in the presence of nitrophenol are introduced. The experimental results have proven that the presence of nitrophenol and the ionic radiuses of the metal ions influence greatly the coordination and supramolecular self-assemblies of these metal ions to Q[5] molecule. Compared to in the absence of p-nitrophenol, the presence of p-nitrophenol seems to frustrate the formation of the K-Q[5] coordination polymer, while the presence of p-nitrophenol induces the formation of Rb- and Cs-Q[5] coordination polymers. Basically, one-dimensional supramolecular chains are constructed of alkaline earth metal ions and Q[5] molecules alternating; the sizes of their ionic radiuses influence the interaction modes in the chain. The formation of the Ca-Q[5] polymer results in the partial coordination of Ca cations to the portals of adjacent Q[5] molecules due to the smaller ionic radiu...

The formation of 3D fused 10-membered “bracelet” frameworks derived from the alkyl-substituted curcurbit[5]urils (SQ[5]s), 1,2,4-hexamethylcucurbit[5]uril (1,2,4-HMeQ[5]), and pentacyclopentanocucurbit[5]uril (PCyHQ[5]) and K+ ions is described. These remarkable catenated structures feature trigonal-planar branching units involving three SQ[5]s connected via their bound K+ ions in a triangular manner in which the coordination of each K+ ion to the five portal carbonyl oxygen atoms of one SQ[5] as well as to a bridging portal carbonyl oxygen from an adjacent SQ[5] draws the edges of three portals into close proximity. The corresponding offset angle at each junction provides the basis for the 3D assembly of the observed fused 10-membered SQ[5] bracelet frameworks.

Three one-dimensional methyl-substituted cucurbituril-based polyrotaxanes, [Ag(H2O)(C4N3)(TMeQ[6])](NO3)3H2O (1), [Cu(H2O)2Cl2(C4N4)(TMeQ[6])]2H2O (2), and [Ag2(H2O)3(C4N4)(TMeQ[6])]2(NO3)14H2O (3) have been prepared with N,N′-bis(3-pyridylmethyl)-1,4-butanediamine (C4N3) and N,N′-bis(4-pyridylmethyl)-1,4-butane diamine (C4N4), incorporating a symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril (TMeQ[6]) using methods assisted by silver(I) and copper(II) ions. X-ray diffraction analyses reveal that all three polyrotaxanes have basically 1D linear chain structures with different shapes. However, the π···π stacking of the protruded pyridyl ring of the guest is observed and leads to the formation of two-dimensional networks in compound 1. Unlike most cases in which a metal ion coordinates to both of the terminal pyridyl nitrogen atoms of two neighboring pseudorotaxanes, the silver ion coordinates to only one terminal pyridyl nitrogen atom and simultaneously coordinates to two carbonyl oxygen atoms of the neigh...

Nine supramolecular self-assembly entities consisting of cucurbit[5]uril, potassium salts, and hydroxybenzene or its derivatives were constructed by conventional methods. In this supramolecular architectural system, Q[5]s and the metal ions (K+) form infinite chains through coordination and ion−dipole interaction, and the stacking of these supramolecular chains then forms wavelike “walls”. The layers of hydroxybenzene or its derivatives are sandwiched by these wavelike walls, and the counteranions are captured in the molecular channels formed by the supramolecular chains. The gap between the adjacent walls is dependent on the size of the hydroxybenzene or its derivatives.