CAREER: SusChEM: Metal Complexes with Pendant Proton Relays for Small Molecule Activation

职业：SusChEM：带有悬垂质子继电器的金属络合物，用于小分子活化

• 批准号: 1555387
• 负责人: Smaranda Marinescu
• 金额: $ 67.5万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2021-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1555387&HistoricalAwards=false
• 关键词: CAREER; SusChEM; Metal; Complexes; Pendant

CHE-1555387 CAREER: Metal Complexes with Pendant Proton Relays for Small Molecule Activation; Smaranda C. Marinescu, University of Southern California (USC)Energy harvested directly from sunlight is an attractive source for filling the global need for power with minimal environmental impact. To avail ourselves of this practically inexhaustible source, several important problems in solar energy capture, storage, and distribution need first to be met in order to harness solar radiation to satisfy global energy demand. One promising method is the use of solar energy to drive chemical reactions that produce easily stored fuels. Carbon dioxide (CO2), the undesirable "greenhouse gas" byproduct of burning fossil fuels and other industrial processes, is potentially an abundant, economic feedstock for solar-driven catalysis to produce hydrocarbon fuels. With inspiration from natural photosynthetic biological systems, Dr. Smarandra Marinescu is developing molecular catalysts for this process. The catalyst architecture is specifically designed with a hydrogen-bonded framework capable of CO2 activation. The research goals of this project are to design and synthesize catalyst complexes of first-row transition metals supported by negatively-charged or neutral molecular fragments (called ligands) able to supply protons needed in the chemical reaction, and to use these metal-ligand complexes to enable conversion of CO2 to CO, the first step in activating the greenhouse gas in the formation of hydrocarbon chemicals. The research has broader societal impact both in developing access to solar energy in an efficient and storable way and in removing the CO2 from the environment, thus turning a harmful waste product into a useful resource. The project also has broader impact in meeting the CAREER-specific criterion of integrating research and educational activities, which involve both students and teachers in the local middle/high schools in energy-related projects and educational experiences. Dr. Marinescu is also developing mentoring programs for women at undergraduate, graduate, and postdoctoral levels to increase the participation of this underrepresented group in science fields. With funding from the Chemical Catalysis Program of the Chemistry Division, Professor Smarandra Marinescu of the Department of Chemistry at University of Southern California is synthesizing several macrocyclic aminopyridine complexes and evaluating their catalytic properties for the reduction of CO2. Preliminary studies indicate that cobalt complexes with pendant NH groups act as efficient electrocatalysts for the reduction of CO2 to CO with excellent Faradaic efficiencies. In comparison, the cobalt complexes with pendant tertiary amines are not as efficient CO2-reduction catalysts, suggesting that the presence of the pendant NH moiety of the secondary amine is crucial for catalysis. Stoichiometric studies are performed to detect and characterize proposed intermediates in the catalytic cycle. The prepared catalysts are studied structurally, electrochemically and spectroscopically to understand their chemical reactivity. These fundamental studies further the fundamental understanding of how hydrogen bonding facilitates the reduction of CO2 and aid in the development of practical catalysts using inexpensive metals. Additionally, there are several broader impacts directly tied to improving and diversifying the pipeline of young scientists interested and engaged in chemistry. The educational components are integrated with energy and catalysis applications, and target middle/high school students and teachers. Dr. Marinescu is also developing mentoring programs for women at undergraduate, graduate, and postdoctoral levels to increase the participation of this underrepresented group in STEM fields.

CHE-1555387 职业：具有悬垂质子继电器的金属络合物，用于小分子活化； Smaranda C. Marinescu，南加州大学 (USC) 直接从阳光中获取的能源是满足全球电力需求且对环境影响最小的一种有吸引力的来源。 为了利用这种几乎取之不尽用之不竭的资源，首先需要解决太阳能捕获、存储和分配方面的几个重要问题，以便利用太阳辐射来满足全球能源需求。一种有前途的方法是利用太阳能驱动化学反应，产生易于储存的燃料。 二氧化碳 (CO2) 是燃烧化石燃料和其他工业过程中不需要的“温室气体”副产品，它可能是太阳能驱动催化生产碳氢化合物燃料的丰富且经济的原料。受到自然光合作用生物系统的启发，Smarandra Marinescu 博士正在为这一过程开发分子催化剂。 该催化剂结构经过专门设计，具有能够活化二氧化碳的氢键框架。该项目的研究目标是设计和合成由带负电或中性分子片段（称为配体）支撑的第一行过渡金属催化剂配合物，能够提供化学反应所需的质子，并使用这些金属配体配合物使二氧化碳转化为二氧化碳，这是激活温室气体形成碳氢化合物的第一步。该研究具有更广泛的社会影响，既以有效和可储存的方式开发太阳能，又消除环境中的二氧化碳，从而将有害的废物转化为有用的资源。 该项目在满足研究和教育活动相结合的特定职业标准方面也具有更广泛的影响，其中涉及当地初中/高中的学生和教师参与与能源相关的项目和教育经验。 Marinescu 博士还在为本科生、研究生和博士后级别的女性制定指导计划，以增加这一代表性不足的群体在科学领域的参与。在化学系化学催化项目的资助下，南加州大学化学系的 Smarandra Marinescu 教授正在合成几种大环氨基吡啶配合物，并评估其还原 CO2 的催化性能。初步研究表明，带有 NH 侧基的钴配合物可作为有效的电催化剂，将 CO2 还原为 CO，并具有出色的法拉第效率。相比之下，带有叔胺侧链的钴配合物并不是有效的 CO2 还原催化剂，这表明仲胺侧链 NH 部分的存在对于催化至关重要。进行化学计量研究是为了检测和表征催化循环中提出的中间体。对所制备的催化剂进行结构、电化学和光谱研究，以了解其化学反应活性。这些基础研究进一步加深了对氢键如何促进二氧化碳还原的基本理解，并有助于使用廉价金属开发实用催化剂。此外，还有一些更广泛的影响与改善和多样化对化学感兴趣并从事化学工作的年轻科学家的渠道直接相关。教育部分与能源和催化应用相结合，针对初中/高中学生和教师。 Marinescu 博士还在为本科生、研究生和博士后级别的女性制定指导计划，以增加这一代表性不足的群体在 STEM 领域的参与。