Covalently Cross-Linked Porous Organic Coordination Crystals

9812351Lee该项目涉及一类多孔有机配位固体，其中的孔径和功能表面特征可以在不损失多孔骨架结构的情况下进行修饰。这些固体目前是由支链苯乙炔通过腈-贵金属配位键连接在一起的。该项目的目标是用有机部分之间的纯共价键反复取代丁腈-金属配位键。提出了通过添加诸如二异氰酸酯和三氟化二硅的交联剂来合成能够在多孔态下彼此交联的具有化学活性的苯乙炔分子。将采取两种平行的综合战略。在第一种策略中，反应性单体有机构建块将通过配位键合，使用模板被固定到所需的多孔结构中。然后，这些物种将相互交叉连接，而不会失去多孔结构。在第二种策略中，低聚物将从有机构建块预组装，然后进行交联以形成多孔共价固体。构建具有理想拓扑结构的有机固体是基于分子和晶体结构之间的相互作用。它还被设想考虑在将分子映射到晶体形状方面的另一种范例。这个范例就是极小曲面的范例。在多孔性固体中，其结晶部分和溶剂部分之间的界面自由能很高，因此采用了受分子结构限制的最小表面积。这一设计原理将被用来制造双钻石或陀螺型的三维多孔固体。这些区域将通过控制局部主干几何形状和通过向初始形状的持久分子添加柔性悬链来规定主干与通道的体积比来进入。%%%坚固的有机多孔固体，具有可调节的空腔大小，应该能够经受住可能应用的必要条件，其中包括分离和催化。***

9812351LeeThe project involves a class of porous organic coordination solids, in which pore size and functional surface character can be modified without the loss of the porous backbone structure. These solids are currently constructed from branched phenylacetylene nitriles linked together through nitrile-noble metal coordination bonds. The goal of the project is the iterative replacement of the nitrile-metal coordination bond with purely covalent linkages between the organic moieties. It is proposed to synthesize chemically reactive phenyl acetylene alcohol molecules capable of being cross-linked to one another in the porous state through addition of cross-linking agents such as diidocyanates and disilyltriflates. Two parallel synthetic strategies will be pursued. In the first strategy, reactive monomeric organic building blocks will be held into the desired porous structure through coordination bonding, using templates. The species will then be cross-linked to one another without loss of porous structure. In the second strategy, oligomers will be pre-assembled from the organic building blocks prior to cross-linking to form porous covalent solids. The construction of organic solids of desired topology is based on the interplay between molecular and crystalline structure. It is also envisioned to consider another paradigm in mapping molecular to crystalline shape. This paradigm is that of minimal surfaces. The interfacial free energy in a porous solid between its crystalline and solvent portions is high and hence adopts minimal surface areas subject to constrains caused by the molecular architecture. This design principle will be used to make three-dimensional porous solids of the double diamond or gyroid type. These regions will be accessed by controlling the local backbone geometry and by dictating the backbone to channel volume ratios through the addition of flexible pendent chains to the initial shape persistent molecules. % % % The robust organic porous solids, with tunable cavity sizes, should be capable of withstanding conditions necessary for possible applications, among them separation and catalysis. ***