描述了新的阳离子大环主体分子的合成。这些大环由连接两个吡唑基的甘脲低聚物组成,两个吡唑基形成面对它们的腔的阳离子壁的一部分。为了增加型腔的尺寸,已经制备了许多衍生物,并且每种新产品都已得到充分表征。对Me 10 Tu [3] 2+的p K a s的初步研究和L-谷氨酰胺的相互作用表明,结合具有H键供体基团的阴离子分子的潜力。
Crystal structures of three partially cyclopentano-substituted cucurbit[6]urils
摘要:
Three new alkyl-substituted cucurbit[6]urils, symmetrical tetracyclopentano cucurbit[6]uril {TCyPO[6]}, meta-tricyclopentano cucurbit[6]uril {m-TriCyPQ[6]} and meta-dicyclopentano cucurbit[6]uril {m-(CyP)(2)Q[6]}, were synthesized by using the controlled synthesis utilizing the readily available dimer of the unsubstituted glycouril, diether of cyclopentano glycoluril and the unsubstituted glycouril. These partial cyclopentano-substituted cucurbit[6]urils were characterized by single-crystal X-ray diffractions. In the crystal structure of compounds 2{TCyPQ[6]}center dot 57H(2)O (1) and {m-TriCyPQ[6]}center dot 23H(2)O (2), both of Q[6]s formed a molecular capsule included water molecules, and the capsules assembled one-dimensional supramolecular chains through the hydrogen bonding. In the crystal structure of compound 2{m-(CyP)(2)Q[6]}center dot(HV)(2+)center dot 4Cl(-)center dot 2(H3O)(+)center dot 44H(2)O (3), a dumbbell shape host-guest inclusion complex N,N-dihexyl-4,4'-bipyridinium(HV2+) with m-(CyP)(2)Q[6] was formed, the m-(CyP)(2)Q[6] host selectively included the alkyl moiety of the guest through the hydrophobic cavity interaction and the ion-dipole interaction. (C) 2008 Elsevier B.V. All rights reserved.
Locating the Cyclopentano Cousins of the Cucurbit[<i>n</i>]uril Family
作者:Feng Wu、Li-Hui Wu、Xin Xiao、Yun-Qian Zhang、Sai-Feng Xue、Zhu Tao、Anthony I. Day
DOI:10.1021/jo2021778
日期:2012.1.6
The synthesis of the first family of fully substituted cuc-urbit[n]uril is discussed, and the structural features of precursor glycolurils are highlighted in their importance to achieving higher homologues. The members of the family, where n = 5-7, have been fully characterized, and increased binding affinities have been identified for dioxane in CyP(6)Q[6] and adamantyl NH3+ in CyP(7)Q[7]. A higher homologue is indicated but not conclusively identified.