CAS-Climate: Supramolecular Control of Reactivity in the Solid State: From Metal-Free Photoswitches and Click Reactivity to Manufacturing Diverse Molecules

非技术摘要：该项目得到了NSF材料研究部固态和材料化学项目的支持，旨在促进对有机固态反应的理解，并提高其价值。这些新的见解使材料研究人员和合成化学家受益匪浅。在有机固体中进行的反应与绿色化学领域相关：它们具有高度选择性、高产率和无溶剂性。在有机固体中进行的反应也可用于储存化学能，这使得固体对于开发可持续性应用的材料很有价值。然而，有机固态被用作进行合成化学和开发可持续材料的介质的潜力，由于缺乏将反应性基团定向成适当几何形状以进行化学反应的通用方法而受到严重阻碍。MacGillivray教授和他的研究小组利用非共价键（例如氢键）来指导晶体中分子的组装，使反应基团正确可靠地排列以进行反应。因此，他们研究在固态下反应的起始材料的范围，以及如何最终制造各种各样的分子和材料作为产品。这项研究有可能为化学工业的“绿色”制造方法奠定基础，在这种方法中，可以使用纯有机固体进行反应，而不使用金属或金属离子。作为该项目推广活动的一部分，高中学生被介绍给非共价键和有机固态化学。主要研究者还涉及来自研究活动中代表性不足的群体的学生，与本科院校保持积极的合作，并让中学生参与促进化学科学（例如X射线晶体学）的职业生涯。 技术摘要：该项目由NSF材料研究部的固态和材料化学计划支持，通过开发形成功能材料基础的固体并扩大反应和产物的范围，使有机固态中进行的反应对合成化学家和材料科学家更具价值。具体来说，研究人员研究了（i）它们作为无金属有机开关的潜力，（ii）使用共晶进行无金属“点击”反应，以及（iii）产生广泛分子的方法。光致变色开关是利用氢键导向的自组装来设计的，该自组装引导分子间[2+2]光二聚。 点击反应是在全氟苯基-苯基相互作用的帮助下进行的，以产生扩展的π-共轭分子。使用芳腈官能化的环丁烷的合成后修饰，在晶体中合成了广泛的分子。这项研究的动机是这样一个事实，即虽然有机固态是一个非常有吸引力的介质进行化学反应，使（和打破）共价键，仍然缺乏一般的方法来执行反应“随意”类似于液相。这项研究的成果有望使固体反应在有机合成的问题和挑战中得到更广泛的应用（例如复杂分子、附加化学反应）、绿色化学（例如无溶剂制备），和材料科学（例如单晶开关）该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的评估被认为值得支持。影响审查标准。

Nontechnical Abstract: This project, with support from the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, aims to advance the understanding of, and enhance the value of, reactions performed in the organic solid state. These new insights benefits materials researchers and synthetic chemists alike. Reactions performed in organic solids are relevant to the field of green chemistry: they are highly selective, high-yielding, and solvent-free. Reactions performed in organic solids can also be used to store chemical energy, which makes the solids valuable to develop materials for applications in sustainability. The potential of the organic solid state to be used as a medium to perform synthetic chemistry and develop sustainable materials, however, has been severely hampered by a lack of a general method to orient reactive groups into the proper geometry to undergo a chemical reaction. Professor MacGillivray and his research group make use of noncovalent bonds (e.g. hydrogen bonds) in a general way to guide the assembly of molecules in crystals so that reactive groups are properly and reliably aligned to undergo reaction. Thereby they study the scope of starting materials that react in the solid state and how to eventually manufacture a wide variety of molecules and materials as products. The research has the potential to lay the foundation for a “greener” manufacturing approach for the chemical industry where reactions can be performed using purely organic solids without the use of metals or metal ions. As part of the project’s outreach activities, high-school students are introduced to noncovalent bonding and organic solid-state chemistry. The principal investigator also involves students from underrepresented groups in the research activities, maintains active collaborations with undergraduate colleges, and engages middle-school students to promote careers in chemical science (e.g. X-ray crystallography). Technical Abstract: The project, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, makes reactions performed in the organic solid state more valuable to synthetic chemists and materials scientists by developing solids that form the basis of functional materials and expand the scope of reactions and products. Specifically, the researchers study (i) their potential as metal-free organic switches, (ii) uses of cocrystals to perform metal-free ‘click’ reactions, and (iii) an approach to generate broad ranges of molecules. Photochromic switches are designed using hydrogen-bond-directed self-assembly that direct intermolecular [2+2] photodimerizations. The click reactions are conducted with the assistance of perfluorophenyl-phenyl interactions to generate extended pi-conjugated molecules. Broad ranges of molecules are synthesized in crystals using post-synthetic modifications of cyclobutanes functionalized with aryl nitriles. The research is motivated by the fact that although the organic solid state is a highly attractive medium to perform chemical reactions to make (and break) covalent bonds, there remains a lack of general methodologies to perform reactions ‘at will’ akin to the liquid phase. Outcomes of this research are expected to enable a broader application of reactions in solids to problems and challenges of organic synthesis (e.g. complex molecules, additional chemical reactions), green chemistry (e.g. solvent-free preparation), and materials science (e.g. single-crystal switches).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.