Pyrrole-Modified Porphyrins: Platforms to Probe the Malleability of Porphyrinoid Conformation and Aromaticity

在化学系的化学结构，动力学和机制-B计划的支持下，康涅狄格大学的Brueckner教授正在研究卟啉和二氢卟酚，它们是参与许多代谢过程和光捕获的“生命色素”的成员。这些研究旨在了解它们的基本性质，使它们对生命如此重要。制备的新化合物还具有表明其在非天然应用中的利用的性质。例如，一些改性材料比天然材料更灵活，变形时会改变颜色。因此，它们适合于生成可以使物理应力可见的材料;这对许多工程学科都很重要。将二氧化碳转化为有价值的产品是我们这个时代的紧迫问题之一。在这些转换中的改性卟啉的一些金属配合物的研究扩展了我们的理解如何最好地做到这一点。这些研究将提供一个多学科和协作的培训基地，为学生在从有机和无机合成到物理有机化学领域，接触到生物物理学和一些生物医学和工程应用。这将为学生将来在工业、学术界或公共服务领域的职业生涯做好准备。拟议的研究重点是通过逐步合成操作卟啉来正式取代卟啉中的吡咯结构单元。这产生了一个所谓的吡咯修饰的卟啉（PMP）家族，其包含一个或多个非吡咯结构单元。通常戏剧性的构象和电子效应-特别是当构建块大于它们所取代的五元吡咯时-正在研究中。这些研究中的一个焦点是取代对PMP芳香性的影响。在卟啉大环的约束下发生的化学转化的欣赏有助于合理设计实用的新型卟啉类化合物。选择构象灵活的PMP在力致变色聚合物的评价划定的范围和限制，利用PMP实现智能材料。一些PMP表明它们具有作为电子汇的能力。这将通过使用其Co（II）配合物在电催化多电子还原二氧化碳来探测。这些努力的成功有可能为卟啉调谐提供重要的长期经验，以建立有用的功能。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

With the support of the Chemical Structure, Dynamics, and Mechanisms-B program in the Division of Chemistry, Professor Brueckner of the University of Connecticut is studying porphyrins and chlorins, members of the ‘pigments of life’ involved in many metabolic processes and light harvesting. These investigations aim at the understanding of their fundamental properties that allowed them to become so important for life. The new compounds prepared also possess properties that suggest their utilization in non-natural applications. For instance, some modified materials are more flexible than their natural counterparts and change their color when deformed. They are therefore suitable to generate materials that can make physical stress visible; this is important for many engineering disciplines. The conversion of carbon dioxide to valuable products is one of the pressing problems of our time. The study of some metal complexes of the modified porphyrins in these conversions expands our understanding how best to do this. These studies will offer a multidisciplinary and collaborative training ground for students in areas ranging from organic and inorganic synthesis to physical organic chemistry, with exposure to photophysics and a number of biomedical and engineering applications. This will prepare students well for future careers in industry, academia, or public service.The proposed study focuses on the formal replacement of a pyrrolic building block in porphyrins by stepwise synthetic manipulation of porphyrins. This generates a family of so-called pyrrole-modified porphyrins (PMPs) incorporating one or more non-pyrrolic building blocks. The often dramatic conformational and electronic effects – especially when the building blocks are larger than the five-membered pyrrole they replace – are being studied. One focus in these studies is the impact the replacement has on the aromaticity of the PMPs. An appreciation for the chemical transformations taking place within the constraints of a porphyrinic macrocycle assists in the rational design of novel porphyrinoids of utility. The evaluation of select conformationally flexible PMPs in mechanochromic polymers delineates the scopes and limits of utilizing PMPs in the realization of smart materials. Some PMPs suggest their capacity to act as electron sinks. This will be probed by the use of their Co(II) complexes in electro-catalytic multi-electron reductions of carbon dioxide. Success in these endeavors has the potential to provide important long term lessons in porphyrin tuning to build in useful function.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.