描述了纳米尺寸的自组装圆柱形胶囊1a x 1a的合成和光谱表征。大型有机客体分子的包封研究是通过在[D12]均三甲苯溶液中使用1H NMR光谱学进行的。除了对胶囊的形状和几何进行计算(MacroModel 5.5,Amber *力场)分析之外,还介绍了一种估算内部空腔尺寸的实验方法。这涉及使用一系列同源分子“规则”(例如芳族酰胺5a-i)。使用这种技术,胶囊1a x 1a内的可用空间估计为5.7 x 14.7 A(误差+/- 0.2 A)。过氧化二苯甲酰易于包封在[D12] 1,3,5-三甲基苯中,并且在胶囊内在70℃下表现出至少三天的稳定分解作用。此外,1a x 1a可防止封装的过氧化物氧化溶液中存在的Ph3P或二苯基咔嗪。过氧化物的正常化学反应性可通过DMF从胶囊中释放出来,而DMF是一种竞争氢键的溶剂,它将氢键保持在一起。对于胶囊在催化和传递中的应用,被包裹物种的保护和释放预示着良好的发展。
Supramolecular Architecture with a Cavitand-Capsule Chimera
作者:Agustí Lledó、Seiji Kamioka、Aaron C. Sather、Julius Rebek
DOI:10.1002/anie.201006166
日期:2011.2.7
Molecule‐within‐molecule complexes are widely used in supramolecular chemistry for studies of molecular recognition and catalysis. Self‐assembled hosts isolate their guests from the bulk media and reveal unique molecular behaviors. An assembly that features well‐differentiated and non‐interacting binding sites stabilized through hydrogen‐bonding interactions is described (see picture).
Self-Assembly Dynamics of a Cylindrical Capsule Monitored by Fluorescence Resonance Energy Transfer
作者:Elizabeth S. Barrett、Trevor J. Dale、Julius Rebek
DOI:10.1021/ja071774j
日期:2007.7.1
The constituent cavitands of a cylindrical capsule were labeled with donor and acceptor fluorophores, and fluorescence resonance energy transfer (FRET) was employed as a tool to study the dynamics of self-assembly. When donor and acceptor dyes are present in the same capsular assembly, they are brought within 25 A of each other, a distance suitable for efficient energy transfer to occur between them
圆柱形胶囊的组成空腔用供体和受体荧光团标记,荧光共振能量转移 (FRET) 被用作研究自组装动力学的工具。当供体和受体染料存在于同一个囊状组件中时,它们彼此之间的距离在 25 A 之内,该距离适合在它们之间发生有效的能量转移。这允许研究纳摩尔浓度的相互作用物种,提供从 NMR 实验中无法获得的信息。研究了在各种客体分子存在下胶囊的动力学稳定性,这表明圆柱形胶囊交换速率的范围超过 4 个数量级。虽然胶囊的热力学稳定性通常决定自组装动力学,
Steric and Magnetic Asymmetry Distinguished by Encapsulation
作者:Toru Amaya、Julius Rebek
DOI:10.1021/ja049043w
日期:2004.5.1
Guests in an achiral cavity experience asymmetric magnetic environments induced by chiral centers outside the cavity.
Container Molecules with Portals: Reversibly Switchable Cycloalkane Complexation
Guest-Induced, Selective Formation of Isomeric Capsules with Imperfect Walls
作者:Wei Jiang、Julius Rebek
DOI:10.1021/ja3090737
日期:2012.10.24
The majority of building blocks in self-assembled capsules feature high symmetry. Reducing this symmetry inevitably leads to expanded possibilities for isomerism. Here, we report a deep cavitand host with one short and three long walls. Its dimerization to hydrogen-bonded capsules in the presence of suitable guest molecules can lead to two constitutional isomers. A given guest induces the predominant formation of only one isomer. The unexpected selectivity is interpreted in terms of the different hydrogen-bonding patterns of the capsules and their effects on the size, shape, and dynamics of the capsules' spaces.