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

基本信息

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

项目摘要

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.

由于该废物的潜力是一种易于使用的，可持续的，无毒的和廉价的化学原料，因此将二氧化碳（CO2）转化为更有价值的化合物是一个重要目标。基于过渡金属（例如镍或钯）的催化剂表现出希望加快二氧化碳的反应，以使其实用，但是进一步实施需要提高效率。在这个项目中，耶鲁大学的哈扎里博士正在发展对二氧化碳如何使用实验和计算技术与多种过渡金属配合物相互作用的理解。这些知识对于设计改进的二氧化碳使用系统至关重要，因为它将提供有关如何修改催化剂以及如何改善执行反应（温度，压力等）的条件的信息。这项研究具有提高选择性的潜力，因此仅形成所需的产品。这项研究是由哈扎里博士参与与二氧化碳利用有关的一系列外展活动完成的。这些活动的重点是来自代表性不足的科学，技术，工程和数学（STEM）学科的学生。这些活动包括为纽黑文地区的高中学生提供的为期一周的夏季能源计划，以及在哈扎里博士实验室进行研究的机会。借助化学结构，动力学和机制B（CSDM-B）计划的资金，耶鲁大学的Hazari博士正在对将二氧化碳插入到后期过渡金属债券中的基本了解。这项研究提供了有关催化剂设计和涉及二氧化碳利用碳的反应条件的优化的指导。具体而言，正在测量二氧化碳插入的速率，正在测量10匹匹匹匹匹匹匹匹匹匹杆的过渡金属氢化物，氢氧化物，烷基和芳基的速率。正在探测的因素包括金属中心，辅助配体，溶剂和添加剂（例如路易斯酸）对二氧化碳插入动力学的影响。一个主要重点是扩展关系的发展，将二氧化碳插入速率与金属氢化物（动力学特性）的速率与过渡金属氢化物（热力学特性）的混合相关。这可以评估与次级配位效应（例如氢键或静电效应）稳定二氧化碳插入过渡态之类的假设。密度功能理论计算是与实验工作并行进行的，并探测了过渡状态的结构，确定不稳定中间体的几何形状，并衡量中间体的几何形状。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子的智力和更广泛的影响来评估NSF的法定任务。