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.

在这个由化学部化学催化计划资助的项目中，巴黎圣母院的塞思·布朗教授正在开发新型的催化剂，以利用氧气制造新化合物并从现有化合物中去除氢。 催化剂是加速并直接对理想产品的反应而无需食用的化合物。 许多催化剂含有金属原子，周围的有机化合物被称为配体，在大多数催化剂中，反应化学发生在金属原子上。 布朗教授正在研究使配体与金属原子一起参与催化或执行所有催化本身的方法。正在研究催化剂的结构特征以及制造或破裂的化学键的机制，并且该信息被用于设计新的配体，应进行更好的催化。 由于催化是总计全球国内生产总值和大多数商业化学产品和化学过程的过程的过程，因此发现新的或改进的有机反应催化剂可能会对经济发展和增长产生重大影响。 研究这些问题的研究团队包括高中生，本科生和研究生，目的是发展其技术和智力技能，以适当为他们做好适当的培训和科学或工程职业的准备。布朗正在为新的多层次氧化还原活性配体做好准备，以创建“无分类”反应的环境。 一个靶标是氧原子转移或二氧化物激活，其中将在金属中心形成与氧气的键，但氧化还原事件将在配体中发生。 一个关键的设计元素是使用高配位数，该数字可以稳定诸如Peroxo复合物之类的小咬合角中间体，并允许在金属周围组装足够的配体，以在单个位点填充多达四个电子。 探索第二类反应是基于底物的一致，纯粹以配体为中心的1,2-脱水。 这些也可以通过协调饱和的金属配合物来执行，这可能会导致更大的催化剂寿命。 这种反应的范围以及轨道对称约束将引导此类反应的选择性的可能性。 新型的催化机制通常打开新的选择性途径，了解哪些电子和结构特征使反应更有效地可能导致改善的催化剂，并影响化学物质和化学燃料的使用或产生。 正在开发一系列的教育材料，以帮助使入门学生能够快速采用化学动力学的实用方法，从而使学生能够在研究的早期阶段从事这项工作。

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.