Nonclassical Oxidation Reactions

非经典氧化反应

• 批准号: 1465104
• 负责人: Seth Brown
• 金额: $ 56万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1465104&HistoricalAwards=false
• 关键词: Nonclassical; Oxidation; Reactions

In this project funded by the Chemical Catalysis Program of the Chemistry Division, Professor Seth Brown of the University of Notre Dame is developing new types of catalysts to utilize oxygen to make new compounds and to remove hydrogen from existing compounds. Catalysts are compounds that accelerate and direct reactions toward desirable products without themselves being consumed. Many catalysts contain a metal atom and surrounding organic compounds bound to it, called ligands, and in most catalysts the reaction chemistry occurs on the metal atom. Professor Brown is studying ways in which to make the ligand participate in the catalysis along with the metal atom or to perform all of the catalysis itself. The structural features of the catalysts and the mechanisms through which the chemical bonds are made or broken are being studied, and this information is being used to design new ligands that should perform better catalysis. Because catalysis accounts for processes that total one third of the global gross domestic product and a majority of the commercial chemical products and chemical processes, the discovery of new or improved catalysts for organic reactions can have a great impact on economic development and growth. The research team investigating these issues includes high school students, undergraduate students, and graduate students, with the aim of developing their technical and intellectual skills to prepare them appropriately for further training and careers in science or engineering.Professor Brown is preparing new multidentate redox-active ligands to create environments where "nonclassical" redox reactions can take place. One target is oxygen atom transfer or dioxygen activation in which bonds to oxygen will be formed at the metal center, but redox events will take place at the ligands. A key design element is the use of high coordination numbers, which may stabilize small bite angle intermediates such as peroxo complexes and allow the assembly of enough ligands around the metal to marshal up to four electrons at a single site. A second class of reactions being explored is based on concerted, purely ligand-centered 1,2-dehydrogenations of substrates. These can be carried out even by coordinatively saturated metal complexes, which may lead to greater catalyst lifetimes. The scope of such reactions, and the possibility that orbital symmetry constraints will steer the selectivity of such reactions, are being explored. Novel catalysis mechanisms often open up new selectivity pathways, and understanding what electronic and structural features make the reactions more efficient may lead to improved catalysts with impact in the use or production of chemicals and chemical fuels. A series of educational materials are being developed to help bring introductory students up to speed on practical approaches to chemical kinetics, allowing students to be intellectually engaged with the work at an early stage in their studies.

在这个由化学系化学催化计划资助的项目中，圣母大学的Seth Brown教授正在开发新型催化剂，以利用氧气制造新化合物并从现有化合物中去除氢。 催化剂是一种化合物，它能加速和引导反应生成所需的产物，而自身不会被消耗。 许多催化剂含有金属原子和与其结合的周围有机化合物，称为配体，并且在大多数催化剂中，反应化学发生在金属原子上。 布朗教授正在研究如何使配体沿着金属原子一起参与催化作用，或者使配体本身完成所有的催化作用。目前正在研究催化剂的结构特征和化学键形成或断裂的机制，这些信息正用于设计新的配体，这些配体将发挥更好的催化作用。 由于催化剂占全球国内生产总值的三分之一，占商业化学产品和化学工艺的大部分，因此发现新的或改进的有机反应催化剂对经济发展和增长具有重大影响。 研究小组的成员包括高中生、本科生和研究生，目的是培养他们的技术和智力，为将来的科学或工程专业培训和职业生涯做好准备。布朗教授正在制备新的多齿氧化还原活性配体，以创造“非经典”氧化还原反应发生的环境。 一个目标是氧原子转移或分子氧活化，其中在金属中心将形成与氧的键，但在配体处将发生氧化还原事件。 一个关键的设计元素是使用高配位数，这可以稳定小咬角中间体，如过氧配合物，并允许在金属周围组装足够的配体，以在单个位点上组装多达四个电子。 第二类正在探索的反应是基于一致的，纯粹的配体为中心的1，2-取代底物。 这些甚至可以通过配位饱和的金属络合物进行，这可以导致更长的催化剂寿命。 目前正在探索这类反应的范围，以及轨道对称性限制将控制这类反应的选择性的可能性。 新的催化机制通常会开辟新的选择性途径，了解哪些电子和结构特征使反应更有效，可能会导致改进催化剂，对化学品和化学燃料的使用或生产产生影响。 正在开发一系列教育材料，以帮助入门学生快速掌握化学动力学的实用方法，使学生在学习的早期阶段就能在智力上参与这项工作。

项目成果

High-valent osmium iminoxolene complexes

高价锇亚胺氧烯配合物

• DOI: 10.1039/d0dt01735c
• 发表时间: 2020
• 期刊: Dalton Transactions
• 影响因子: 4
• 作者: Gianino, Jacqueline;Erickson, Alexander N.;Markovitz, Sean J.;Brown, Seth N.
• 通讯作者: Brown, Seth N.

Amphiphilicity in Oxygen Atom Transfer Reactions of Oxobis(iminoxolene)osmium Complexes

Oxobis(iminoxolene)锇配合物的氧原子转移反应中的两亲性

• DOI: 10.1021/acs.inorgchem.1c00068
• 发表时间: 2021
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: Erickson, Alexander N.;Gianino, Jacqueline;Markovitz, Sean J.;Brown, Seth N.
• 通讯作者: Brown, Seth N.

On the border between localization and delocalization: tris(iminoxolene)titanium( iv )

定位与离域的边界：tris(iminoxolene)titanium( iv )

• DOI: 10.1039/c8dt04528c
• 发表时间: 2019
• 期刊: Dalton Transactions
• 影响因子: 4
• 作者: Marshall-Roth, Travis;Yao, Kun;Parkhill, John A.;Brown, Seth N.
• 通讯作者: Brown, Seth N.

Mono- and bimetallic pentacoordinate silicon complexes of a chelating bis(catecholimine) ligand

• DOI: 10.1039/c9dt02475a
• 发表时间: 2019-08-14
• 期刊: DALTON TRANSACTIONS
• 影响因子: 4
• 作者: Do, Thomas H.;Brown, Seth N.
• 通讯作者: Brown, Seth N.

Highly covalent metal–ligand π bonding in chelated bis- and tris(iminoxolene) complexes of osmium and ruthenium

锇和钌螯合双和三（亚胺氧烯）配合物中的高共价金属-配体-键合

• DOI: 10.1039/d0dt01287d
• 发表时间: 2020
• 期刊: Dalton Transactions
• 影响因子: 4
• 作者: Gianino, Jacqueline;Brown, Seth N.
• 通讯作者: Brown, Seth N.