RUI:Targeted Structural Diversity and Assessments in Quasiracemates

非技术摘要在材料研究部门的固态和材料化学计划的支持下，Kraig惠勒（化学）和Diana Schepens（数学）之间的合作合成和表征了独特的材料家族，这些材料在分子晶体中可预测地排列。虽然许多负责分子相互作用的结构细节是已知的，但也存在通过对整个分子识别过程同样重要的不明确或弱接触产生较难管理的基序的化学特征。分子形状就是这样一种结构特征，也是本研究的重点。这项研究的目的是了解如何利用有机小分子的形状在晶体中构建可预测的分子组装体。这项工作的结果提供了必要的信息，可转移到功能材料的设计分子的形状空间。此外，鉴于所研究的小分子有机化合物的独特分子识别特征和计算机辅助发现方法的发展，从这些研究中获得的知识有助于更全面地了解广泛类别化合物的自组装过程。该项目通过在惠特沃思大学（一所以本科为主的大学）进行实验和计算机辅助研究的实践经验，支持对一批本科生和高中生进行培训。外联工作还包括支持夏季X射线晶体学会议，来自全国各地的参与者在那里接受必要的培训，为他们正在进行的教学和研究计划。技术总结这个跨学科的项目结合了实验固态有机化学和数学拓扑学，以研究如何近对映体组装成积极有利的结晶组件。本研究利用拟配位法建构双分子化合物，探讨分子形状对分子识别过程的结构界限。使用苯甲酰基氨基酸分子支架制备由已知有机前体配制的手性结构单元。虽然准外消旋体的研究已经发展成为一门成熟的科学，但组装准对映体对的细节仍然相对未知。该项目探讨了如何通过强氢键增加晶格稳定性，从而获得具有更大结构变化的准对映体组分的材料。目标系统的行为，预计提供关键的洞察分子识别概况。晶体学，视频辅助热显微镜，量热和晶格能计算被用来评估这些材料形成quasiracemic材料的能力。这项研究还开发了用于确定quasienantiomeric组件对的形状空间差异和反演对称度的计算机方法，这将为quasirachetry prediction.This奖提供诊断工具，反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Non-Technical SummaryWith the support of the Solid State and Materials Chemistry Program in the Division of Materials Research, the collaboration between Kraig Wheeler (Chemistry) and Diana Schepens (Mathematics) synthesizes and characterizes unique families of materials that align predictably in molecular crystals. While many structural details responsible for molecular interactions are known, there also exist chemical features that produce less manageable motifs via ill-defined or weak contacts that are no less critical to the overall molecular recognition process. Molecular shape is one such structural feature and the focus of this investigation. The goal of this research is to understand how the shape of small organic molecules can be used to advantage to construct predictable molecular assemblies in crystals. Findings from this work supply necessary information about the shape space of molecules that is transferable to the design of functional materials. In addition, given the unique molecular recognition profiles of the small organic compounds under study and the development of computer-aided discovery methods, the knowledge gained from these studies contributes to a more comprehensive understanding of the self-assembly process for broad classes of compounds. This project supports the training of a cohort of undergraduate and high school students through hands-on experiences in experimental and computer-assisted research at Whitworth University, a predominantly undergraduate institution. Outreach efforts also include support for a summer X-ray crystallography conference, where participants from across the country receive essential training for their ongoing teaching and research programs.Technical SummaryThis interdisciplinary project combines experimental solid-state organic chemistry and math topology to examine how near enantiomers assemble into energetically favorable crystalline assemblies. The research explores the structural boundaries of molecular shape to the molecular recognition process by using the quasiracemate approach for constructing bimolecular compounds. Chiral building blocks formulated from known organic precursors are prepared using benzoyl amino acid molecular scaffolds. Though the study of quasiracemic materials has now progressed to an established science, the intimate details of assembling pairs of quasienantiomers remain relatively unknown. This project explores how increasing crystal lattice stabilization via strong hydrogen bonds leads to materials with a greater structural variation of the quasienantiomeric components. The behavior of the target systems is expected to offer critical insight into molecular recognition profiles. Crystallographic, video-assisted thermomicroscopy, calorimetric, and lattice energy calculations are utilized to assess the ability of these materials to form quasiracemic materials. This study also develops in silico methods for determining the shape space differences and degree of inversion symmetry of pairs of quasienantiomeric components that will provide diagnostic tools for quasiracemate prediction.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.