SusChEM: Redox Non-Innocence in N- and C-donor Chelate Complexes of 1st Row Transition Elements: Radical Character in Chemistry

SusChEM：第一行过渡元素的 N 和 C 供体螯合物中的氧化还原非纯真：化学中的自由基特征

• 批准号: 1402149
• 负责人: Peter Wolczanski
• 金额: $ 60万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1402149&HistoricalAwards=false
• 关键词: SusChEM; Redox; Non; Innocence; donor

This project, funded by the NSF Chemical Synthesis Program in the Division of Chemistry, supports the research of Professor Peter T. Wolczanski of Cornell University to explore the design and synthesis of first row transition metal complexes containing ligands that expand the chemistry of the metal, primarily through oxidation and reduction processes. The coordinating ligands feature nitrogen (N)- and carbon (C)-donors with multiredox capability, that is they are "redox non-innocent" (RNI) by virtue of giving or taking electrons from the metal, thereby increasing the metal's reactivity. The Wolczanski group employs many first row transition metals such as iron and chromium, making complexes that are uniquely reactive and more environmentally-friendly and sustainable than current precious metal complexes. Professor Wolczanski and his group are active in the local community, actively planning and participating in multi-week after-school experiments for the Chemistry Club at Caroline Elementary School in Ithaca, New York. This research project focuses on experimental studies that seek to: expand the scope of first row transition metal complexes that express redox non-innocence, increase the field strengths about first row transition metals via chelation and metal-carbon bonds, prepare new species capable of unique carbon-carbon bond-forming processes, and generate metal-carbon clusters based on dicarbides. Redox non-innocent (RNI) ligands "electronically buffer" transition metal centers and expand their ability to conduct redox events inherent to bond-making and bond-breaking reactions. This research project focuses on the application of N-donor chelates to the chemistry of first row transition metal complexes, with an emphasis on stabilizing metal-nitrogen and -carbon multiple bonds while rendering them reactive. Operational, functionality tolerant, first row olefin metathesis catalysts are a critical target. The preparation of nitrogen and carbon-based chelates possessing the strong fields are necessary to transform first row transition metal complexes into those capable of second or third row reactivity. Studies also focus on C-C bond-making, featuring metal-stabilized carbanions that possess radical character. Radical hydrocarbon bond activations have led to ligand design features for hydrogen-atom abstraction and C-C couplings; these bond-making processes are scrutinized with regard to scope and the potential for catalysis. Graduate and undergraduate researchers are actively involved in both the experimental and theoretical aspects of the project. The students receive training in several characterizational techniques including Electron Paramagnetic Resonance and Mossbauer spectroscopies as well as magnetometry and electronic structure calculations.

该项目由 NSF 化学部化学合成计划资助，支持康奈尔大学 Peter T. Wolczanski 教授的研究，探索包含配体的第一排过渡金属配合物的设计和合成，这些配体扩展了金属的化学性质，主要通过氧化和还原过程。配位配体具有具有多重氧化还原能力的氮 (N) 和碳 (C) 供体，也就是说，它们通过从金属中给予或夺取电子而实现“非无害氧化还原”(RNI)，从而提高金属的反应性。 Wolczanski 集团采用了许多第一排过渡金属，例如铁和铬，制造的络合物具有独特的反应性，并且比当前的贵金属络合物更加环保和可持续。 Wolczanski 教授和他的团队活跃于当地社区，积极规划和参与纽约伊萨卡卡罗琳小学化学俱乐部为期数周的课后实验。该研究项目侧重于实验研究，旨在：扩大表达氧化还原非无辜的第一行过渡金属配合物的范围，通过螯合和金属-碳键增加第一行过渡金属的场强，制备能够具有独特功能的新物种碳-碳键形成过程，并生成基于二碳化物的金属-碳簇。 氧化还原非无害（RNI）配体“电子缓冲”过渡金属中心，并扩展其进行成键和断键反应固有的氧化还原事件的能力。该研究项目的重点是氮供体螯合物在第一排过渡金属配合物化学中的应用，重点是稳定金属-氮和-碳多重键，同时赋予它们反应性。可操作、功能耐受的第一排烯烃复分解催化剂是一个关键目标。 制备具有强场的氮基和碳基螯合物是将第一排过渡金属配合物转化为具有第二或第三排反应活性的配合物是必要的。 研究还集中于 C-C 键的形成，其特点是具有自由基特性的金属稳定碳负离子。自由基碳氢键活化导致了氢原子提取和 C-C 偶联的配体设计特征；这些成键过程的范围和催化潜力均受到严格审查。 研究生和本科生研究人员积极参与该项目的实验和理论方面。 学生们接受多种表征技术的培训，包括电子顺磁共振和穆斯堡尔谱以及磁力测量和电子结构计算。