CAS: Taming the Reactivity of Base Metal Hydrides Through Bifunctional Ligands

在化学系化学催化项目的支持下，辛辛那提大学的关海荣教授将研究具有金属氢键的分子（即金属氢化物）作为脂肪酸甲酯、二氧化碳和糖源多元醇加氢或还原的催化剂。这些催化过程对于化学工业来说是非常理想的，因为化学工业生产许多消费品中使用的表面活性剂，并将可再生材料转化为燃料和增值化学品。该项目将侧重于利用地球上资源丰富、价格低廉的金属，如锰、铁、钴、镍和铜来设计这种催化剂。为了提高金属氢化物的反应活性，并尽量减少催化剂的降解，将使用不仅参与氢转移而且与金属紧密结合的配体。该项目将通过一系列项目，包括美国化学会项目SEED计划、美国国家科学基金会本科生研究经验计划和辛辛那提大学科学与工程女性（WISE）计划，为高中生、本科生和研究生提供严格的培训。通过这个项目，关教授还将为资源有限的社区学院或机构开发实验课程的研究材料，为少数族裔学生提供研究机会，并通过与当地化学公司合作，促进学生的专业发展。在化学系化学催化项目的支持下，辛辛那提大学关海荣教授将研究提高贱金属氢化物反应活性的策略，贱金属氢化物是许多加氢或还原过程的关键中间体。设计双功能和强螯合配体的假设是，它们可以降低金属的作用，参与双电子转移，或抑制簇的形成。具体的研究目标包括开发基于铁和镍的更强大和更活跃的加氢催化剂，设计锰和钴的羟基环戊二烯配合物作为掩面金属氢化物，以及追求膦连接的单核铜氢化物。为了支持该项目的广泛影响，关教授将积极参与一些项目，重点为少数民族学生提供研究机会，包括来自合作本科院校的学生。以研究为基础的教材将在化学教育文献和其他机构中更广泛地传播。与当地公司的积极合作将着眼于提高学生在工业环境中解决问题的能力。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。

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Hairong Guan of the University of Cincinnati will study molecules with metal-hydrogen bonds (i.e., metal hydrides) as catalysts for the hydrogenation or reduction of fatty acid methyl esters, carbon dioxide, and sugar-derived polyols. These catalytic processes are highly desirable to the chemical industry that manufactures surfactants used in many consumer products, and converts renewable materials to fuels and value-added chemicals. This project will focus on the use of earth-abundant, inexpensive metals such as manganese, iron, cobalt, nickel, and copper to design such catalysts. To enhance the reactivity of the metal hydrides and to minimize degradation of the catalysts, ligands that not only participate in hydrogen transfer but also bind tightly to the metals will be employed. The project will contribute to the rigorous training of a diverse group of high school, undergraduate, and graduate students via a number of programs including the American Chemical Society Project SEED Program, the NSF Research Experience for Undergraduates program, and the University of Cincinnati’s Women in Science and Engineering (WISE) Program. Through this project, Professor Guan will also develop research-based materials for a laboratory course that can be used by community colleges or institutions with limited resources, provide research opportunities to underrepresented minority students, and enhance student professional development through collaborations with local chemical companies.With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Hairong Guan of the University of Cincinnati will study the strategies of improving the reactivity of base metal hydrides, which are key intermediates in many hydrogenation or reduction processes. Bifunctional and strongly chelating ligands will be designed under the hypothesis that they can deemphasize the roles played by the metals, participate in two-electron transfer, or suppress cluster formation. The specific research objectives include the development of more robust and active hydrogenation catalysts based on iron and nickel, the design of hydroxycyclopentadienyl complexes of manganese and cobalt as masked metal hydrides, and the pursuit of phosphine-ligated mononuclear copper hydrides. In support of the broader impacts of the project, Professor Guan will actively engage in programs focusing on providing research opportunities to underrepresented minority students including those from collaborating primarily undergraduate institutions. Research-based teaching materials will be disseminated more broadly in the chemical education literature and to other institutions. Active collaborations with local companies will be geared toward enhancing student problem-solving skills in an industrial setting.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.