Preparation of Microporous Solids from Molecular Building Blocks

该项目由无机、生物无机和有机金属化学项目资助，将支持亚利桑那州立大学Omar Yaghi教授从可溶性分子构建块合成新型多孔固体的研究。该项目的重点是发展和理解与从分子构建块制备固体相关的两个基本问题：1)如何控制分子组分的相对方向，使所得到的结构具有所需的结构、稳定性和物理性质；2)如何获得晶体形式的固体产品，使其结构易于确定。使用的一般方法将涉及无机团簇或适当功能化的配位化合物的室温缩聚，使用聚合物基质作为加成共聚和缩聚反应的扩散和反应介质。预期的沸石型结构有望具有可容纳客体分子或离子的空隙，从而在分离、离子交换和催化方面有用。原则上，这些框架结构可以通过化学修饰和操纵来改变它们的性质。多孔固体这个术语适用于一类包含孔道和空隙的网状固体，其大小与许多小分子和离子相当。这些物质通常会扩散到这些固体中，以交换现有的离子，或者作为分子间相互作用的结果保留下来。这种固体在工业上广泛用于分子结构的选择性吸附和催化转化，特别是通过酸催化途径。这种材料通常是通过高温工艺合成的，通常不能提供结晶产品。本研究项目将尝试通过各种类型的室温缩聚反应，通过在预期结构的小预先形成的碎片之间形成键来合成多孔固体。聚合基质将被用作反应介质，以防止形成更密集的结构，并减缓缩合过程，使晶体更容易形成。从这个项目中得到的材料可能在分离技术和催化方面有用。

This project, funded by the Inorganic, Bioinorganic and Organometallic Chemistry Program, will support the research of Professor Omar Yaghi of Arizona State University on the synthesis of new porous solids from soluble molecular building blocks. The focus of the project is the development and understanding of two fundamental issues that are relevant to the preparation of solids from molecular building blocks: 1) how to control the relative orientation of the molecular components so that the resulting structure has the desired structure, stability and physical properties, and 2) how to obtain the solid product in crystalline form so that its structure is readily determined. The general method to be used will involve the room-temperature condensation polymerization of inorganic clusters or suitably functionalized coordination compounds using polymeric matrices as diffusion and reaction media for addition copolymerization and condensation polymerization reactions. The anticipated zeolitic type structures are expected to have voids that can accommodate guest molecules or ions and thus to be useful in separations, ion-exchange, and catalysis. In principle, these framework structures can be chemically modified and manipulated to predictably vary their properties. The term porous solid applies to a class of network solids that contain channels and voids that are comparable in size to many small molecules and ions. Such species often may diffuse into these solids to be exchanged for an existing ion or to be otherwise retained as a result of intermolecular interactions. Such solids are widely used industrially for the selective adsorption and catalytic transformation of molecular structures, particularly through acid catalyzed pathways. Such materials are usually synthesized by high temperature processes that often do not provide crystalline products. This research project will attempt the synthesis of porous solids by formation of bonds between small pre-formed fragments of the desired structure through various types of room-temperature, condensation polymerization reactions. Polymeric matrices will be used as reaction media to prevent the formation of more dense structures and to slow the condensation process such that crystals are more likely to be formed. The materials that result from this project may be useful in separations technology and in catalysis.