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CAS: Can the Ionic Character of 1st Row and the Covalency of 2nd and 3rd Row Transition Metals Converge?

CAS：第一行的离子特征和第二行和第三行过渡金属的共价性可以收敛吗？

基本信息

批准号：
1953884
负责人：
Peter Wolczanski
金额：
$ 76万
依托单位：
Cornell University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1953884&HistoricalAwards=false
关键词：
CAS Ionic Character 1st Row

项目摘要

General Public Abstract:The Chemical Synthesis Program of the Chemistry Division of the National Science Foundation supports the research of Professor Peter T. Wolczanski of Cornell University. The project seeks to train candidates in the fields of metal-centered chemistry. Most commodity (bulk) and fine (pharmacological) chemicals are synthesized utilizing catalysts. These catalysts are typically transition metal compounds that accelerate the rates of reaction. Many of these catalysts use metals that are in low abundance, toxic, and expensive. This program is studying the synthesis of cheaper catalysts, but they must be modified by organic materials -- termed ligands -- in order to provide the chemical reactivity necessary to replace the current generation of catalysts used in industry. One general solution being explored is the investigation of ligands that promise to render the cheaper metals more versatile or adaptable. Another general approach is to synthesize metal systems that will underpin truly transformative processes: the preparation of compounds that are capable of multistep chemical reactions. A specific application targets the synthesis of complexes using propellar-shaped molecules that rupture to give what are called alkylidene ligands. Synthesis of alkylidene-metal compounds would have broad implications for the advanced manufacturing within the U.S. chemical industry. The Cornell group is also supports STEM education of 5th grade and high school students. The STEM efforts include lecture materials and hands-on training modules. These activities are helping to strengthen the workforce available to support the US chemical industry.Technical Abstract:The Chemical Synthesis Program of the Chemistry Division of the National Science Foundation supports the research program of Professor Peter T. Wolczanski of Cornell University. The project seeks to train PhD candidates in the fields of inorganic and organometallic chemistry. The research identifies several reactions that are potentially transformative in regards to commodity (bulk) and fine (pharmacological) chemicals production. Typical transition metals used in catalysis are in low abundance and costly, and the work proposes to supplant these species with inexpensive 1st and 2nd row species. Various ligand platforms that display redox non-innocence, including a reversible C-C bond formation, are employed to expand the redox capacity of several first-row metals. Other 3- coordinate chelates are also involved in H-transfer chemistry to further expand the scope of reactivity. Exploration of ionic vs. covalent bonding is fundamental to the work. Transfer HX and H2 additions, akin to transfer hydrogenations, and processes like hydroformylation, are targeted with early metal systems. Specific systems show potential for tandem CH activation in conjunction with olefin metathesis, leading to a net exchange of H2 for CH2, and one tridentate ligand has the potential for an alternate polymerization mechanism to Ziegler-Natta. Unique strained reagents are employed as alkylidene generators for numerous transition metals, as replacing expensive Ru-based olefin metathesis catalysts is an important target. The production of independent, versatile PhDs capable of adapting to a challenging and fluctuating academic or industrial market is a major objective, and the further development of Charge Distribution Via Reporters (CDVR) as a pedagogical alternative to formal oxidation states will continue to be tested. The Cornell group is also preparing a general 5th grade outreach program for publication based on experience, and is developing a related outreach program for high school students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

摘要：美国国家科学基金会化学部化学合成项目资助了康奈尔大学Peter T. Wolczanski教授的研究。该项目旨在培养以金属为中心的化学领域的候选人。大多数商品（散装）和精细（药理学）化学品都是利用催化剂合成的。这些催化剂通常是加速反应速率的过渡金属化合物。许多这些催化剂使用的金属丰度低、有毒且昂贵。这个项目正在研究更便宜的催化剂的合成，但它们必须由有机材料修饰——称为配体——以提供取代工业上使用的当前一代催化剂所必需的化学反应性。目前正在探索的一个通用解决方案是研究配体，以期使廉价的金属更具通用性或适应性。另一种一般的方法是合成金属系统，这将支持真正的变革过程：制备能够进行多步化学反应的化合物。一个特定的应用目标是合成配合物，使用螺旋桨形状的分子，破裂产生所谓的烷基二烯配体。烷基金属化合物的合成将对美国化学工业的先进制造产生广泛的影响。康奈尔小组还支持五年级和高中生的STEM教育。STEM项目包括讲座材料和实践培训模块。这些活动有助于加强可用于支持美国化学工业的劳动力。技术摘要：美国国家科学基金化学部化学合成项目资助康奈尔大学Peter T. Wolczanski教授的研究项目。该项目旨在培养无机和有机金属化学领域的博士候选人。该研究确定了几种在商品（散装）和精细（药理学）化学品生产方面具有潜在变革性的反应。催化中使用的典型过渡金属丰度低，价格昂贵，本工作建议用价格低廉的第一和第二行金属取代这些金属。各种显示氧化还原非清白的配体平台，包括可逆的C-C键形成，被用来扩大几种第一排金属的氧化还原能力。其他3-配位螯合物也参与了h转移化学，进一步扩大了反应性的范围。离子与共价键的探索是这项工作的基础。转移HX和H2的添加，类似于转移氢化，以及氢甲酰化等过程，是早期金属系统的目标。特定体系显示出与烯烃复分解相结合的连续CH活化的潜力，导致H2与CH2的净交换，并且一种三叉戟配体具有与Ziegler-Natta交替聚合机制的潜力。由于取代昂贵的钌基烯烃转化催化剂是一个重要的目标，因此采用独特的应变试剂作为许多过渡金属的烷基烯生成剂。培养能够适应具有挑战性和波动的学术或工业市场的独立、多才多艺的博士是一个主要目标，进一步发展电荷分布通过报告（CDVR）作为正式氧化态的教学替代方案将继续进行测试。康奈尔大学小组还根据经验准备了一份通用的五年级外展计划，并正在为高中生制定相关的外展计划。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

TEMPO coordination and reactivity in group 6; pseudo-pentagonal planar (η 2 -TEMPO) 2 CrX (X = Cl, TEMPO)

第 6 组的 TEMPO 协调性和反应性；

DOI：
10.1039/d2cc03838b
发表时间：
2022
期刊：
Chemical Communications
影响因子：
4.9
作者：
Kayser, Ann K.;Wolczanski, Peter T.;Cundari, Thomas R.;Bollmeyer, Melissa M.;Lancaster, Kyle M.;MacMillan, Samantha N.
通讯作者：
MacMillan, Samantha N.

Attempts at generating metathesis-active Fe(IV) and Co(IV) complexes via the reactions of (silox)2M(THF)2, [(silox)3M][Na(THF)2] (M = Fe, Co), and related species with propellanes and triphenylboron

尝试通过 (silox)2M(THF)2, [(silox)3M][Na(THF)2] (M=Fe, Co) 的反应生成复分解活性 Fe(IV) 和 Co(IV) 配合物