Controlling Self-assembly through Host-Guest Chemistry: Metallo-supramolecular Assemblies with Stellated Polyhedral Structures

小分子可以通过氢键或金属-配体配位相互作用组织成具有不同几何形状（特别是多面体形状，如立方体和八面体）的大组件。化学家对这些组件感兴趣，因为它们通常是纳米尺寸和高度复杂的，但在适当的条件下，有效地使自己处于一个称为自组装的过程中。它们通常显示出内部空间，其他分子可以被捕获甚至反应，就像纳米尺寸的反应容器一样。在这样的有限空间内进行化学可能会产生与在本体solution.We发现的结果完全不同的建议，使用具有刚性的金字塔形状的配位体，以产生非常大的金属配位体组装与多面体结构，有一个星状的方面。多面体的恒星看起来像从面发出的尖峰或金字塔。我们正在寻找与类似斯特拉八面体和星状的小nuboctahedron等结构的组件。它们被称为星爆棱镜。虽然这些类型的结构在数学上是已知的，但在化学中很少有这样的例子。我们将使用的配体是已知的分子宿主，这意味着它们可以识别或结合其他分子-特别是它们与富勒烯有很大的亲和力。因此，我们可能能够捕获富勒烯或其他客体分子内的这些金属配体组件的星座。配体的主体-客体化学可用于控制或操纵整体自组装。离散的星状组装体将具有全部指向内的配体结合位点，结合位点之间具有特定的几何关系。因此，模板客人与互补的几何形状和大小，或简单的小客人将有利于特定的离散星状组件。由于其尺寸或功能基团的位置而与离散结构不互补的客体分子将有利于聚合物金属配体材料，称为配位聚合物。这些星状组装体（和任何配位聚合物）将通过固态（例如X射线晶体学，热技术）和溶液技术（例如质谱，DOSY NMR）进行研究。将研究组装体的主-客体行为，以开发组装体作为纳米尺寸的反应容器、在催化、在分子分离和其它领域中的未来应用。

Small molecules can be organised into large assemblies with distinct geometric shapes (especially polyhedral shapes such as cubes and octahedra) through the use of hydrogen bonding or metal-ligand coordination interactions. These assemblies are of interest to chemists because they are often nano-sized and highly complicated but, given the right conditions, effectively make themselves in a process called self-assembly. They often show internal space where other molecules can be trapped or even react, acting like nano-sized reaction vessels. Chemistry performed inside such confined spaces may produce results quite different to those found in bulk solutions.We propose to use ligands that have a rigid pyramidal shape to produce very large metal-ligand assemblies with polyhedral structures that have a stellated aspect. Stellations of a polyhedron look like spikes or pyramids emanating from the faces. We are looking to make assemblies with structures resembling stella octangula and stellated small cubicuboctahedron amongst others. These are dubbed the starburst prisms. While these types of structures are known mathematically there are very few examples of them in chemistry. The ligands we will use are known to be molecular hosts which mean that they can recognise or bind other molecules - in particular they have a great affinity with fullerenes. Hence we may be able to trap fullerenes or other guest molecules inside the stellation of these metal-ligand assemblies. The host-guest chemistry of the ligands can be used to control or manipulate the overall self-assembly. Discrete stellated assemblies will have the ligand binding sites all pointing inwards with particular geometric relationships between the binding sites. Hence templating guests with complementary geometries and sizes, or simply small guests will favour particular discrete stellated assemblies. Guest molecules that are not complementary for discrete structures due to their size or positioning of functional groups will instead favour polymeric metal-ligand materials, known as coordination polymers.These stellated assemblies (and any coordination polymers) will be studied by solid state (e.g. X-ray crystallography, thermal techniques) and solution techniques (e.g. mass spectrometry, DOSY NMR). the host-guest behaviour of the assemblies will be studied with a view to developing future applications of the assemblies as nano-sized reaction vessels, in catalysis, in molecular separations, and other fields.