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.

该项目由化学系NSF化学合成计划资助，支持康奈尔大学Peter T.Wolczanski教授的研究，探索设计和合成包含配体的第一排过渡金属络合物，这些配体主要通过氧化和还原过程扩展金属的化学。配位配体的特点是氮(N)-和碳(C)-给体具有多氧化还原能力，即它们通过给予或带走金属的电子而是“氧化还原非无害”(RNI)，从而提高了金属的反应活性。Wolczanski集团使用了许多第一排过渡金属，如铁和铬，制造出具有独特活性的络合物，比目前的贵金属络合物更环保和可持续。Wolczanski教授和他的团队活跃在当地社区，积极为纽约伊萨卡卡罗琳小学的化学俱乐部策划和参与为期数周的课后实验。本研究项目侧重于实验研究，旨在扩大表现氧化还原非无辜性质的第一排过渡金属络合物的范围，通过螯合和金属-碳键增加第一排过渡金属的场强，制备能够形成独特碳-碳键过程的新物种，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，并扩大他们的能力进行氧化还原事件固有的成键和断键反应。本研究项目集中于N-施主络合物在第一排过渡金属络合物化学中的应用，重点在于稳定金属-氮和-碳多键，同时使它们具有反应性。可操作的、功能性容忍的第一排烯烃歧化催化剂是一个重要的目标。为了将第一排过渡金属络合物转变为具有第二排或第三排反应活性的配合物，需要制备具有较强电场的氮基和碳基络合物。研究还集中在C-C键的形成，具有自由基性质的金属稳定的碳负离子。自由基碳氢键的活化导致了氢原子抽象和C-C偶联的配体设计特征；这些成键过程从范围和催化潜力方面进行了仔细的审查。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。学生们接受了几种表征技术的培训，包括电子顺磁共振和穆斯堡尔谱学，以及磁测量和电子结构计算。