Modular Transition Metal Chalcogenide Coordination Polymers

现代社会是建立在不断增长的技术进步之上的。近几十年来，这一进步来自于复杂的加工和工程，也许最好的例证是微型化，主要是由纳米科学的激增推动的。相反，从根本上说，新材料的发现更加有限，许多现代创新依赖于体硅等经典材料。一类新的材料，称为配位聚合物，代表了一种非常有吸引力的系统，用于合理设计和调整具有定制性能的新材料。虽然在这一领域取得了巨大的进步，但这些材料的组成仍然存在根本限制，阻碍了它们在潜在的变革性应用中的使用，如可再生能源、下一代电子产品和新的磁性材料。这一基础研究项目由材料研究部的固态和材料化学计划支持，指导发现了一种基于硫基节点和连接物的新型配位聚合物家族。与大多数依赖于氧或氮基成分的配位聚合物不同，硫基材料在其各自的构建块之间显示出强烈的相互作用，从而增强了它们的电子和磁性。通过基础合成技术的进步和广阔的组成范围，这些新设计的材料有可能在革命性技术中实现新的应用。在这些研究工作的同时，首席调查员在芝加哥地区建立了一个地方会议，专门针对包括本科生、研究生和当地博士后研究人员。这次会议在芝加哥地区产生了一个研究人员社区，并与正在进行的与年轻学生的努力联系在一起，以增加科学交流和扫盲。技术概述与发现新的硫系配位聚合物相关的关键基本挑战是为新材料家族生成可靠的合成协议。这种合成方案相对较好地适用于具有羧酸盐连接体的更经典的配位聚合物材料。一些基于硫化物的配位聚合物的早期例子显示出显著的性能和活性，但与其O-和N-基同系物相比，这些材料是稀缺的，后者源于更少了解的合成协议。需要对这些材料进行精确的合成控制，以调整形态、结晶度、溶解度和电子结构。这一基础研究项目得到材料研究部固态和材料化学计划的支持，建立了亟需的可靠的合成控制，这对于理解和调整体属性(如导电性或磁性)至关重要，其中缺陷和颗粒大小可能对观察到的行为具有决定性作用。合成方案和由此产生的一系列新材料使我们能够详细研究物理性质，并更清楚地阐明硫族化合物的加入是如何促进磁和电子耦合的。此外，这些努力使配位聚合物中加入了新的组分：例如，研究人员研究了新的基于硫化物的连接体以及多核硫化物簇合物等新节点。对各种新材料的综合利用和对其特性的详细了解相结合，使得对其功能的合理调整和控制成为可能。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical Summary Modern society is built on ever increasing technological advances. Recent decades have seen this advancement come from sophisticated processing and engineering perhaps best exemplified by miniaturization largely driven by the surge in nanoscience. Conversely, the discovery of fundamentally new materials has been more limited and many modern innovations rely on classic materials such as bulk silicon. A new class of materials, known as coordination polymers, represent an extremely attractive system for the rational design and tuning of new materials with tailored properties. While there have been dramatic advances in this area, there are still fundamental limitations in the composition of these materials that prevent their use in potentially transformative applications such as renewable energy, next generation electronics, and new magnetic materials. This fundamental research project, supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, guides the discovery of a novel family of coordination polymers built upon sulfur-based nodes and linkers. Unlike most coordination polymers which rely upon oxygen- or nitrogen-based components, sulfur-based materials exhibit strong interactions between their individual building blocks which enhances their electronic and magnetic properties. Through advances in the fundamental synthetic techniques and an expansive compositional scope, these newly designed materials have the potential to enable new applications in revolutionary technology. In parallel with these research efforts, the principle investigator establishes a local conference in the Chicago area, particularly aimed at including undergraduate students, graduate students, and local postdoctoral researchers. This conference generates a community of researchers in the Chicago area as well as a link to ongoing efforts with younger students to increase scientific communication and literacy. Technical Summary The key fundamental challenge associated with the discovery of new chalcogenide-based coordination polymers is the generation of reliable synthetic protocols for families of novel materials. Such synthetic protocols are relatively well established for more classic coordination polymer materials with carboxylate linkers. Several early examples of chalcogenide-based coordination polymers exhibit remarkable properties and activity, but there is a dearth of these materials compared to their O- and N-based congeners which arises from more poorly understood synthetic protocols. Precise synthetic control over these materials is required to tune morphology, crystallinity, solubility, and electronic structure. This fundamental research project, supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, establishes the much needed reliable synthetic control that is essential for understanding and tuning bulk properties such as conductivity or magnetism, where defects and grain sizes may have a determinative role on the observed behavior. The synthetic protocols and the resulting family of new materials enables the detailed study of physical properties and more clearly elucidates how the incorporation of chalcogenides mediates enhanced magnetic and electronic coupling. Furthermore, these efforts enable the inclusion of new components into coordination polymers: for example, the researchers study new chalcogenide-based linkers as well as new nodes such as polynuclear chalcogenide clusters. The combination of synthetic access to a variety of new materials and a detailed understanding of their properties enables rational tuning and control over their functionality.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.