Conductive Metal-Organic Frameworks

非技术描述：具有精确设计的纳米级孔的海绵状晶体对于气体的有效分离和储存至关重要。在技术上，纳米多孔半导体也显示出作为电池电极、化学传感器、电催化剂和电致变色材料的组成材料的前景。然而，直到最近，纳米多孔晶体几乎完全被视为电子绝缘体。这种限制源于维持稳定的孔结构所需的非常强的化学键的构架。因此，合成新的、导电的、多孔的晶体是一个固有的违反直觉的挑战。生产这种材料的努力将推动过渡金属节点和有机连接体的晶格的稳定性和电荷离域的极限。技术说明：金属有机框架是由有机桥连配体连接在一起的无机节点组成的微孔网络固体。虽然金属-有机框架因其显著的气体吸附和分离性能而被广泛开发，但与大多数多孔无机材料一样，它们本质上是离子和电子绝缘体。尽管有这些性质，这类材料提供了一个独特的机会，探索在低维纳米多孔系统中的远程离子和电子传输。迄今为止已经研究的导电框架的明显缺乏不是固有的结构限制，而是缺乏对电子感兴趣的结构基序的关注的结果。也就是说，绝大多数骨架由氧化还原非活性的闭壳过渡金属和有机配体组成。作为回应，将开发通过合成开壳和氧化还原模糊支架而产生的具有体电子导电性的金属有机框架。更广泛地说，电子导电金属有机框架的研究将探索低密度混合固体中长距离电子通信的限制，并阐明控制所得性质的主要因素。由于它们的结晶度和易于官能化，金属有机框架也可以作为优秀的模型系统，以更好地理解和增强纳米通道和纳米多孔固体中的离子传输。因此，新的离子传导框架的合成和表征，重点是众所周知的难以在固态下进行的离子将被追求。

NON-TECHNICAL DESCRIPTION: Sponge-like crystals with precisely designed nanometer scale pores are critically important for the efficient separation and storage of gases. Technologically, nanoporous semiconductors also show promise as component materials in battery electrodes, chemical sensors, electrocatalysts, and electrochromic materials. Until recently, however, nanoporous crystals have been almost exclusively typecast as electronic insulators. This limitation originates from the trusswork of very strong chemical bonds needed to maintain a stable pore structure. As such, the synthesis of new, electrically conductive, porous crystals stands as an inherently counterintuitive challenge. Efforts toward producing such materials will push the limits of stability and charge delocalization across a crystalline latticework of transition metal nodes and organic linkers. TECHNICAL DESCRIPTION: Metal-organic frameworks are microporous network solids composed of inorganic nodes linked together by organic bridging ligands. While metal-organic frameworks have been extensively developed for their remarkable gas sorption and separation properties, like most porous inorganic materials, they are essentially ionic and electronic insulators. In spite of these properties, this class of materials offers a unique opportunity to explore long-range ion and electron transport in low-dimensional nanoporous systems. The apparent lack of conductive frameworks that have been investigated thus far is not an inherent structural limitation, but rather a result of a lack of focus on electronically interesting structural motifs. That is, the vast majority of frameworks are composed of redox-inactive, closed shell transition metals and organic ligands. In response, metal-organic frameworks engendered with bulk electronic conductivity through the synthesis of open shell and redox-ambiguous scaffolds will be developed. More broadly, the investigation of electronically conductive metal-organic frameworks will explore the limits of long-range electronic communication in low-density hybrid solids and elucidate the primary factors governing the resulting properties. Owing to their crystallinity and the ease of functionalization, metal-organic frameworks can also serve as excellent model systems to better understand and enhance ion transport in nanochannels and nanoporous solids. Thus, the synthesis and characterization of new ion conducting frameworks with a focus on ions that are notoriously difficult to conduct in the solid-state will be pursued.