Fluorescent PN-Heterocycles in Supramolecular Chemistry and Recognition

在美国国家科学基金会化学部大分子、超分子和纳米化学项目的支持下，俄勒冈大学的Michael Haley教授和Darren Johnson教授及其学生将研究一类新的分子，这些分子包含相邻的磷和氮中心作为整体结构的一部分。这些“PN-杂环”的特点是在紧凑的荧光核心中，一个强氢键供体与一个强受体相邻。基础超分子化学是这一提议的核心，我们的研究将探索和扩大这些容易制备的分子作为荧光材料、用于自组装和分子识别的强氢键基序以及超分子材料的用途。该项目为研究生和本科生研究人员提供跨学科的研究培训。该项目的更广泛影响还包括(1)大学、国家实验室和公司的实习机会，(2)个人发展计划，(3)区域/国际合作；(4)指导机会，以确保学生接受深度的技术培训和广泛的专业培训，以开始他们的职业生涯。PI致力于指导本科生的研究和创新，这表明这项研究将产生广泛的影响。这项基础研究旨在设计和合成PN-杂环作为新的荧光团，并作为超分子化学、有机材料和分子/离子识别的识别基序。本项目的目标是围绕以下两个互补的主要目标组织的：(1)在手性拆分、有机材料和具有扩展共轭和/或原生互变互变的新型稠环芳烃方面进行基础研究；(2)探索PN-杂环在氢键驱动的自组装、氧离子识别和手性识别等超分子化学中的应用。这个研究计划的最终目的是扩大对这些新的PN-杂环的基本了解，并将这些研究扩展到超分子化学和分子识别。这些新杂环的优点是具有非常强的氢键基序和固有的荧光支架，将手性识别和信号转导元件直接放在识别和组装的位置。本研究采用量热、核磁共振光谱和分光光度滴定等多种方法来确定超分子受体的结合性质，并更好地了解结构变化对其结合亲和力、选择性和光电性质的影响。这些研究为研究人员提供了在有机合成、物理有机化学、超分子化学、计算化学、X射线结晶学以及电子结构和分子结构之间的相互作用方面的广泛经验。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。

With the support from the Macromolecular, Supramolecular and Nanochemistry Program of the NSF Chemistry Division, Professors Michael Haley and Darren Johnson and their students at the University of Oregon will investigate a new class of molecules that contain adjacent phosphorous and nitrogen centers as part of overall structure. These "PN-heterocycles" feature a strong hydrogen bond donor adjacent to a strong acceptor within a compact, fluorescent core. Fundamental supramolecular chemistry is at the heart of this proposal, and our studies will explore and expand the utility of these easily-prepared molecules as fluorescent materials, strong hydrogen bonding motifs for self-assembly and molecular recognition, and supramolecular materials. This project provides interdisciplinary research training to graduate and undergraduate researchers. The broader impacts of this project also include (1) internship opportunities at universities, national labs, and companies, (2) individual development plans, (3) regional/international collaborations; and (4) mentoring opportunities to ensure students receive both a depth of technical training and a breadth of professional training to launch their careers. The PI's commitment to mentoring undergraduate research and to innovation suggests that the research will have broad impact.This fundamental research aims to design and synthesize PN-heterocycles as new fluorophores and as recognition motifs in supramolecular chemistry, organic materials, and molecule/ion recognition. The aims of this project are organized around the following two complementary primary objectives: (1) to perform fundamental studies on these PN-heterocycles in the areas of chiral resolution, organic materials, and new fused-arenes featuring extended conjugation and/or prototropic tautomerism; and (2) to explore the utility of PN-heterocycles in supramolecular chemistry in the areas of hydrogen bond-driven self-assembly, oxoanion recognition, and chiral recognition. The ultimate goal of this research program is to expand the fundamental understanding of these new PN-heterocycles and extend these studies into supramolecular chemistry and molecular recognition. These new heterocycles have the advantage of featuring a very strong hydrogen bonding motif with an inherently fluorescent scaffold, putting both chiral recognition and signal transduction elements directly at the site of recognition and assembly. This research employs a combination of methods, including calorimetric, NMR spectroscopic, and spectrophotometric titrations, to determine the binding properties of the supramolecular receptors and to gain a better understanding of how structural changes influence their binding affinity, selectivity, and optoelectronic properties. The studies provide the researchers with broad experience in organic synthesis, physical organic chemistry, supramolecular chemistry, computational chemistry, X-ray crystallography, and the interplay between electronic structure and molecular architecture.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.