Versatility in Templated Solid-State Reactions

技术概述：本项目的总体目标是增加小分子模板在控制有机固态化学反应性方面的通用性。在材料研究部固态和材料化学项目的支持下，该研究旨在通过确定模板的能力来增加多功能性：(i)作为烯烃[2+2]光二聚化的超分子催化剂，（ii）实现交叉光二聚化，（iii）指导桨板的构建。这项研究的动机是，尽管近年来小分子模板提供了对有机固体中双分子反应性的高水平控制，但模板仍然需要超越以前的方法。能够在有机固体状态下控制反应性对于分子和聚合物合成（例如溶液中不可获得的产品，立体控制反应性），绿色化学（例如无溶剂合成），无机化学（例如配体设计）和材料科学（例如数据存储）的应用具有吸引力。晶体填充的影响在很大程度上阻碍了化学家在类似溶液的固体中实现一定程度的反应性控制。模板通过在超分子组装中预先组织烯烃以进行反应，从而避免了填充问题。我们期望推广一种基于机械化学原理的研磨方法，使固体中的超分子催化成为氢键供体和氢键受体催化剂，以及不同的分子识别基团。我们计划使用模板来指导共晶固溶体和三元共晶中的交叉光二聚化。我们还旨在利用模板来指导[24](1,3,5)-和[24]（1,2,4,5）环烷或桨烷形式的多面体分子的超分子结构。该方法将利用模板的能力来强制多个C=C键的反应性排列，从而使新的目标分子可用。在材料研究部固态和材料化学项目的支持下，本项目的总体目标是增加小分子的多功能性，以作为控制晶体中有机分子反应性的模板。能够控制反应性对于分子和聚合物合成（例如在溶液中不可获得的产品，立体控制反应性），绿色化学（例如无溶剂合成），无机化学（例如配体设计）和材料科学（例如数据存储）的应用具有吸引力。本科生和研究生所经历的广泛培训将涉及代表性不足的群体和少数民族，这将继续使参与者能够立即进入劳动力市场。这些活动将在爱荷华大学建立一个新的本科实验室，利用计算化学来评估来自固态的反应性超分子复合物的稳定性。将为本科生举办一年一度的“职业日”，其中将整合PI开发的关于x射线晶体学和粉末衍射的“工作周末”研讨会。PI还将开发一个网站，以支持中西部有机固体化学研讨会（MOSSCS），这是美国中西部地区的年度会议，支持本科生和研究生的演讲。我们提出的实验室实验，以及我们之前报道的和最近开发的固体反应实验，将通过MOSSCS网站以电子方式发布和传播。我们的研究包含了绿色化学的许多核心原则（例如催化，无溶剂合成），这意味着我们可以使用有机固态化学作为一种工具，积极影响合成化学在社会中的作用。

Technical Summary:The general goal of this project is to increase the versatility of small-molecule templates in controlling chemical reactivity in the organic solid state. With support from the Solid-State and Materials Chemistry program in the Division of Materials Research, the research aims to increase versatility by determining the ability of the templates to: (i) serve as supramolecular catalysts of [2+2] photodimerizations of olefins, (ii) make available cross-photodimerizations, and (iii) direct the construction of paddlanes. The research is motivated by the fact that although small molecule templates have, in recent years, provided a high level of control of bimolecular reactivity in organic solids, there remains a need for the templates to go beyond previous methodologies. Being able to control reactivity in the organic solid state is attractive for applications in molecular and polymer synthesis (e.g. products unavailable in solution, stereocontrolled reactivity), green chemistry (e.g. solvent-free synthesis), inorganic chemistry (e.g. ligand design), and materials science (e.g. data storage). Effects of crystal packing have largely prevented chemists from achieving a degree of control of reactivity in solids akin to solution. The templates circumvent the packing problem by preorganizing olefins within supramolecular assemblies for reaction. We expect to generalize a grinding method based on principles of mechanochemistry that facilitates supramolecular catalysis in solids to hydrogenbond-donor and -acceptor catalysts, as well as different molecular recognition groups. We plan to use the templates to direct cross-photodimerizations within co-crystal solid-solutions and ternary co-crystals. We also aim to employ templates to direct the supramolecular construction of polyhedral molecules in the form of [23](1,3,5)- and [24](1,2,4,5)cyclophanes, or paddlanes. The approach will take advantage of the ability of the templates to enforce reactive alignment of multiple C=C bonds to make available the new target molecules.Non-Technical SummaryWith support from the Solid-State and Materials Chemistry program in the Division of Materials Research, the general goal of this project is to increase the versatility of small-molecules to serve as templates to control the reactivity of organic molecules in crystals. Being able to control reactivity is attractive for applications in molecular and polymer synthesis (e.g. products unavailable in solution, stereocontrolled reactivity), green chemistry (e.g. solvent-free synthesis), inorganic chemistry (e.g. ligand design), and materials science (e.g. data storage). The broad training experienced by the undergraduate and graduate students, which will involve underrepresented groups and minorities, will continue to enable the participants to immediately enter the workforce. The proposed activities will result in a new undergraduate laboratory at the University of Iowa that employs computational chemistry to assess the stability of reactive supramolecular complexes derived from the solid state. An annual "Career Day" for undergraduates will be developed, which will integrate a "Working Weekend" workshop on X-ray crystallography and powder diffraction developed by the PI. The PI will also develop a website to support the Midwest Organic Solid State Chemistry Symposium (MOSSCS), which is an annual meeting in the Midwest region of the United States that supports undergraduate and graduate student presentations. Our proposed laboratory experiment, along with our previously reported and recently developed experiments on solid-state reactions, will be published and disseminated electronically with access from the MOSSCS website. That our research encapsulates many core principles of green chemistry (e.g catalysis, solvent-free synthesis) means that we can use organic solid-state chemistry as a vehicle to positively impact the perception of the role of synthetic chemistry in society.