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

在化学系化学结构、动力学和机理b项目的支持下，康涅狄格大学的Brueckner教授正在研究卟啉和氯，这是“生命色素”的成员，参与许多代谢过程和光收集。这些研究旨在了解它们的基本特性，正是这些特性使它们对生命如此重要。所制备的新化合物还具有表明其在非自然应用中的应用的性质。例如，一些改性材料比天然材料更有弹性，变形时可以改变颜色。因此，它们适用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紧迫的问题之一。对这些转化中改性卟啉的一些金属配合物的研究扩展了我们对如何最好地做到这一点的理解。这些研究将为学生提供从有机和无机合成到物理有机化学等领域的多学科合作培训基地，并接触到光物理学和一些生物医学和工程应用。这将为学生未来在工业、学术界或公共服务领域的职业生涯做好准备。提出的研究重点是通过逐步合成卟啉来正式取代卟啉中的吡啶基。这就产生了一系列所谓的吡咯修饰卟啉（pmp），这些卟啉含有一种或多种非吡咯基。构象和电子效应通常是引人注目的，特别是当构建块大于它们所取代的五元吡咯时，研究人员正在进行研究。这些研究的一个重点是替代对pmp芳香性的影响。对在卟啉类大环的约束下发生的化学转化的认识有助于合理设计实用的新型卟啉类化合物。对机械致色聚合物中选择构象柔性pmp的评价描述了在智能材料实现中利用pmp的范围和限制。一些pmp认为它们具有电子吸收的能力。这将通过在二氧化碳的电催化多电子还原中使用它们的Co（II）配合物来探讨。这些努力的成功有可能为卟啉调优提供重要的长期经验，以构建有用的功能。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

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.