Versatility in Templated Solid-State Reactions

技术概述：该项目的总体目标是增加小分子模板在控制有机固体中的化学反应活性方面的多样性。在材料研究部固态和材料化学项目的支持下，这项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]光二聚的超分子催化剂，(Ii)实现交叉光二聚，以及(Iii)指导桨道的构建。这项研究的动机是这样一个事实，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。能够控制有机固体中的反应性在分子和聚合物合成(如溶液中不可得的产物、立体可控反应)、绿色化学(如无溶剂合成)、无机化学(如配体设计)和材料科学(如数据存储)中的应用具有吸引力。晶体堆积的影响在很大程度上阻碍了化学家实现对固体中类似于溶液的反应性的一定程度的控制。模板通过在用于反应的超分子组件内预先组织烯烃来绕过堆积问题。我们期望将一种基于机械力化学原理的研磨方法推广到氢键供体和受体催化剂以及不同分子识别基团的固体超分子催化。我们计划使用这些模板来指导共晶固溶体和三元共晶中的交叉光二聚反应。我们还旨在使用模板来指导[23](1，3，5)-和[24](1，2，4，5)环番或桨巷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键的反应排列，以获得新的目标分子。非技术摘要在材料研究部固体和材料化学计划的支持下，该项目的总体目标是增加小分子作为模板的多功能性，以控制晶体中有机分子的反应活性。能够控制反应性在分子和聚合物合成(例如，溶液中不可用的产品，立体可控的反应性)、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)中具有吸引力。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群体，这将继续使参与者能够立即进入劳动力大军。拟议的活动将导致在爱荷华大学建立一个新的本科实验室，该实验室使用计算化学来评估从固体衍生的反应性超分子络合物的稳定性。将为本科生设立一年一度的“职业生涯日”，其中将包括由PI开发的关于X射线结晶学和粉末衍射的“工作周末”研讨会。PI还将开发一个网站来支持中西部有机固态化学研讨会(MOSSCS)，这是美国中西部地区的一个年度会议，支持本科生和研究生的演讲。我们提议的实验室实验，以及我们之前报道的和最近开发的关于固态反应的实验，将通过MOSSCS网站以电子方式发布和传播。我们的研究囊括了绿色化学的许多核心原则(如催化、无溶剂合成)，这意味着我们可以将有机固态化学作为一种媒介，积极影响人们对合成化学在社会中作用的认知。

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.