SusChEM: Electronic Structure and Reactivity of Peroxo- and Hydroxomanganese Compounds

在这个由化学系化学结构、动力学和机理B计划资助的项目中，堪萨斯大学化学系的蒂莫西·杰克逊教授正在研究具有有趣化学反应活性的新的过氧锰和羟基配合物。这项研究的目的是确定如何控制这些锰配合物的结构以实现所需的反应。这些知识可以用来减少化学转化的成本和环境足迹，并将促进对人类、植物和细菌中的锰酶的理解。该项目位于无机化学、物理化学和生物化学的交界处，为研究生和本科生提供了一种培训经验。前往国家实验室进行X射线吸收实验可以提供同步辐射方面的培训，包括辐射安全培训。这项研究通过在大学迎新日、大学迷你学院和科学自来水上的演讲向公众传播。在这些论坛中，广大的受众参与到正在进行的化学研究中。这项研究中使用的光谱和理论方法被纳入研究生和本科生课程。这项研究与可持续化学有关，因为它使用了毒性较低、含量较丰富的锰络合物。在合成氧化催化剂中，锰(III)-过氧基加合物经常被认为是形成高价锰氧物种的中间体。众所周知，锰(III)-羟基基序参与了重要的质子耦合电子转移反应。然而，几何结构和电子结构对这些化合物的反应活性的影响还没有很好的定义。该项目的具体目标包括：1)研究氧化能力强的配体支持的锰(III)-过氧基加合物的O-O键活化途径；2)探索配体对锰(III)-过氧基加合物还原活化的影响；以及3)系统地改变锰(III)-羟基配合物的配位场，以建立电子结构扰动与化学反应活性之间的关联。通过这项工作，在分子水平上深入了解了过氧锰(III)物种通过化学和电化学途径激活氧(O)-O键断裂的过程。此外，还探讨了中价氢锰(III)物种的质子耦合电子转移反应。在本科生的生物无机课程中，学生将开发描述相关物理方法的视频模块。这项研究中使用的方法被纳入研究生和本科课程。这项工作的成果通过大学和社区外联活动广泛传播。

In this project funded by the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Professor Timothy Jackson of the Department of Chemistry at the University of Kansas is investigating new manganese peroxo and hydroxo complexes with interesting chemical reactivity. The goal of this research is to determine how the structures of these manganese complexes can be controlled to impart a desired reaction. This knowledge could be used to reduce the cost and environmental footprint of chemical transformations and will advance understanding of manganese enzymes in humans, plants, and bacteria. The project lies at the interface of inorganic, physical and biological chemistry, and provides a training experience for graduate and undergraduate students. Trips to national laboratories to perform X-ray absorption experiments afford training in synchrotron radiation, including radiation safety training. This research is disseminated to the general public via presentations at University Orientation Days, the University Mini-College, and Science on Tap. In these forums, a broad, general audience engages with on-going chemical research. Spectroscopic and theoretical methods used in this research is incorporated into graduate and undergraduate courses. This research has relevance to sustainable chemistry because it uses less toxic and more abundant manganese complexes.Manganese(III)-peroxo adducts are frequently proposed as intermediates in the formation of high-valent manganese-oxo species in synthetic oxidation catalysts. Manganese(III)-hydroxo motifs are known to participate in biologically important proton-coupled electron-transfer reactions. However, the influence of geometric and electronic structure on the reactivity of these compounds is not well defined. Specific aims of the project include: 1) investigation of the O-O bond activation pathways of a manganese(III)-peroxo adduct support by an oxidatively robust ligand; 2) exploration of ligand effects on the reductive activation of manganese(III)-peroxo adducts; and 3) a systematic variation of the ligand field of manganese(III)-hydroxo complexes to develop correlations between electronic structure perturbations and chemical reactivity. Through this work, molecular-level insight into the activation of peroxomanganese(III) species for oxygen (O)-O bond cleavage through chemical and electrochemical pathways are developed. In addition, the proton-coupled electron transfer reactions of mid-valent hydroxomanganese(III) species are explored. In an undergraduate bioinorganic course,students will develop video modules describing relevant physical methods. The methods used in this research are incorporated into graduate and undergraduate courses. The results of this work are disseminated broadly through University and community outreach activities.