Liu Simin, Gibb Bruce C
Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA.
Chem Commun (Camb). 2008 Aug 28(32):3709-16. doi: 10.1039/b805446k. Epub 2008 Jun 6.
High definition self-assemblies, those that possess order at the molecular level, are most commonly made from subunits possessing metals and metal coordination sites, or groups capable of partaking in hydrogen bonding. In other words, enthalpy is the driving force behind the free energy of assembly. The hydrophobic effect engenders the possibility of (nominally) relying not on enthalpy but entropy to drive assembly. Towards this idea, we describe how template molecules can trigger the dimerization of a cavitand in aqueous solution, and in doing so are encapsulated within the resulting capsule. Although not held together by (enthalpically) strong and directional non-covalent forces, these capsules possess considerable thermodynamic and kinetic stability. As a result, they display unusual and even unique properties. We discuss some of these, including the use of the capsule as a nanoscale reaction chamber and how they can bring about the separation of hydrocarbon gases.
高分辨率自组装体，即那些在分子水平上具有有序结构的自组装体，最常见的是由具有金属和金属配位位点的亚基，或能够参与氢键作用的基团制成。换句话说，焓是组装自由能背后的驱动力。疏水效应使得（名义上）有可能不依赖焓而是熵来驱动组装。基于这一想法，我们描述了模板分子如何在水溶液中触发穴状配体的二聚化，并且在此过程中被封装在形成的胶囊内。尽管这些胶囊不是通过（焓驱动的）强方向性非共价力结合在一起，但它们具有相当大的热力学和动力学稳定性。因此，它们表现出不同寻常甚至独特的性质。我们讨论其中的一些性质，包括将胶囊用作纳米级反应室以及它们如何实现烃类气体的分离。
