Understanding the Reactions of Carbon Dioxide with Late Transition Metal Complexes

了解二氧化碳与后过渡金属配合物的反应

• 批准号: 1953708
• 负责人: Nilay Hazari
• 金额: $ 45万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1953708&HistoricalAwards=false
• 关键词: Understanding; Reactions; Carbon; Dioxide; Late

The conversion of carbon dioxide (CO2) into more valuable compounds is an important goal due to the potential of this waste product as a readily available, sustainable, non-toxic, and inexpensive chemical feedstock. Catalysts based on transition metals, such as nickel or palladium, show promise speeding up the reactions of carbon dioxide so that they are practical, but improvements in efficiency are required for further implementation. In this project, Dr. Hazari of Yale University is developing an understanding of how carbon dioxide interacts with a variety of transition metal complexes using both experimental and computational techniques. This knowledge is crucial for the design of improved systems for carbon dioxide utilization as it will provide information on how to modify the catalyst as well as how to improve the conditions under which reactions are performed (temperature, pressure, etc.). This research has potential to increased selectivity so that only desired products are formed. The research is complemented by Dr. Hazari’s involvement in a series of outreach activities related to carbon dioxide utilization. These activities focus on students from underrepresented minorities in science, technology, engineering and mathematics (STEM) disciplines. The activities include a one week summer program on energy for high school students in the New Haven area and opportunities for undergraduates to perform research in Dr. Hazari’s laboratory. With funding from the Chemical Structure, Dynamics, and Mechanisms B (CSDM-B) Program of the Chemistry Division, Dr. Hazari from Yale University is developing a fundamental understanding of the insertion of carbon dioxide into late-transition metal bonds. This research provides guidance about the design of catalysts and optimization of reaction conditions for processes involving carbon dioxide utilization. Specifically, the rates of carbon dioxide insertion into Group 10 pincer-supported transition metal hydrides, hydroxides, alkyls, and aryls are being measured. Factors that are being probed include the effects of the metal center, ancillary ligand, solvent, and additives, such as Lewis acids, on the kinetics of carbon dioxide insertion. A major focus is the development of scaling relationships that correlate the rate of carbon dioxide insertion into a metal hydride (a kinetic property), with the hydricity of transition metal hydrides, a thermodynamic property. This enables the evaluation of hypotheses relating to whether secondary coordination sphere effects such as hydrogen bonding or electrostatic effects that stabilize the transition state for carbon dioxide insertion. Density Functional Theory calculations are carried out in parallel with the experimental work and probe the structure of the transition states, determine the geometries of unstable intermediates, and measure hydricity.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.

将二氧化碳(CO2)转化为更有价值的化合物是一个重要的目标，因为这种废物作为一种容易获得、可持续、无毒和廉价的化学原料具有潜力。以过渡金属为基础的催化剂，如镍或钯，显示出加速二氧化碳反应的希望，使其切实可行，但需要提高效率才能进一步实施。在这个项目中，耶鲁大学的哈扎里博士正在利用实验和计算技术来理解二氧化碳如何与各种过渡金属络合物相互作用。这一知识对于设计改进的二氧化碳利用系统至关重要，因为它将提供关于如何修改催化剂以及如何改善进行反应的条件(温度、压力等)的信息。这项研究有可能提高选择性，以便只形成所需的产品。除了这项研究之外，哈扎里博士还参与了一系列与二氧化碳利用有关的外联活动。这些活动侧重于科学、技术、工程和数学(STEM)学科中代表性不足的少数族裔的学生。这些活动包括为纽黑文地区的高中生提供为期一周的能源暑期项目，以及为本科生提供在哈扎里博士的实验室进行研究的机会。在化学部化学结构、动力学和机制B(CSDM-B)项目的资助下，耶鲁大学的哈扎里博士正在发展对二氧化碳插入后过渡金属键的基本理解。本研究为二氧化碳利用过程中催化剂的设计和反应条件的优化提供了指导。具体地说，正在测量二氧化碳插入第10族钳形支撑的过渡金属氢化物、氢氧化物、烷基和芳基的速率。正在探索的因素包括金属中心、辅助配体、溶剂和添加剂(如Lewis酸)对二氧化碳插入动力学的影响。一个主要的重点是建立标度关系，将二氧化碳插入金属氢化物的速率(一种动力学性质)与过渡金属氢化物的水合程度(一种热力学性质)联系起来。这使得能够评估有关二次配位球效应(如氢键)或静电效应(稳定二氧化碳插入的过渡态)的假设。密度泛函理论计算与实验工作并行进行，并探索过渡态的结构，确定不稳定中间体的几何形状，并测量氢化物。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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

Correlating Thermodynamic and Kinetic Hydricities of Rhenium Hydrides

• DOI: 10.1021/jacs.2c07192
• 发表时间: 2022-09-21
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Ertem, Mehmed Z.;Hazari, Nilay;Smith, Nicholas E.
• 通讯作者: Smith, Nicholas E.