CAS: CAREER: Light-Initiated C-H Functionalization by Metal Oxo Complexes for Sustainable Light Hydrocarbon Upgrading

在化学部（CHE）化学催化（CAT）计划和刺激竞争研究（EPSCoR）办公室既定计划的资助下，路易斯安那州立大学（LSU）的Matthey Chambers将致力于开发利用太阳能（光）作为可再生能源的方法，以推动碳氢化合物转化为商品化学品。碳氢化合物功能化是化学工业和能源经济的基石，但今天产生增值商品化学品和燃料的方法通常依赖于高温、高压和对环境有害的试剂。这导致了巨大的能源消耗，因为蒸汽重整和相关工艺占全球能源消耗的1-10%。 受生物系统的启发，有效地利用含有金属-氧活性位点的特殊分子辅因子，该项目将研究与光的相互作用可以启动这些基序选择性地介导惰性烃催化转化为产物的方式。作为路易斯安那州立大学化学演示计划的主任，钱伯斯博士将积极参与社区，并为整个地区服务不足和代表性不足的K-12学生提供实践科学经验。该项目具有潜在的长期广泛的影响，与化学工业相关的可持续催化。Matthew Chambers和他的团队将研究早期过渡金属氧光化学性质（光吸收，发射能量和寿命）和反应模式的基础因素。将通过稳态和瞬态发光光谱实现光化学表征，并通过NMR光谱和GC-MS分析确定产物分布。重点将放在更亲氧的平台上，因为在激发时，这些系统可以有效地激活C-H键，同时允许激活的底物进行各种各样的后续反应，以获得广泛的产品。这些转换的选择性是相关的实验和计算的中间体的M-OH键离解能，因为这被认为是影响产品选择性的关键参数。还将研究实现高效和稳定的光催化平台的方法。动力学研究的目的是确定金属氧代光催化剂再氧化过程中的关键步骤，而辅助配体场的变化是针对发展的关键功能的理解影响光催化剂。总的来说，这些目标预计将导致加强对金属氧代光化学和支持选择性的参数的理解。了解影响光激发金属氧化物的催化反应性的因素将构成使能技术，具有潜在的适用性，以开发新的石化技术和燃料形成reactions.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

With the funding from the Chemical Catalysis (CAT) Program of the Division of Chemistry (CHE) and the Established Program to Stimulate Competitive Research (EPSCoR) office, Matthey Chambers of the Louisiana State University (LSU) will work to develop methods to employ solar energy (light) as a renewable energy source to drive the conversion of hydrocarbons to commodity chemicals. Hydrocarbon functionalization is the cornerstone of the chemical industry and the energy economy, but methods for generating value-added commodity chemicals and fuels today typically rely on high temperatures, high pressures, and environmentally hazardous reagents. This has the consequence of dramatic energy usage, as steam reforming and related processes account for 1-10% of global energy consumption. Motivated by biological systems that efficiently use special molecular cofactors containing metal-oxygen active sites, this project will investigate the manner in which interactions with light can actuate these motifs to selectively mediate the catalytic conversion of inert hydrocarbons to products. As the director of LSU’s ChemDemo program, Dr. Chambers will actively engage communities and provides hands-on science experiences to underserved and underrepresented K-12 students throughout the region. This project has potential long term broader impacts related to sustainable catalysis of relevance to the chemical industry.Matthew Chambers and his group will investigate the factors that underpin early transition metal oxo photochemical properties (light absorption, emission energy, and lifetimes) and reactivity patterns. Photochemical characterization will be achieved via steady-state and transient luminescence spectroscopy and product distributions will be determined by NMR spectroscopy and GC-MS analysis. An emphasis will be placed on more oxophilic platforms as, upon excitation, these systems may efficiently activate C–H bonds while allowing the activated substrate to undergo a diverse array of follow-up reactivity to achieve a broad range of products. The selectivity of these transformations is related experimentally and computationally to the M–OH bond dissociation energies of the intermediates as this is thought to be the critical parameter influencing product selectivity. Also under investigation will be methodologies to achieve efficient and stable photocatalytic platforms. Kinetic studies will aim to identify the key steps during the reoxidation of the metal oxo photocatalyst while ancillary ligand field variations are directed at developing an understanding of the critical features impacting photocatalysis. Collectively, these aims are expected to lead to enhanced understanding of metal oxo photochemistry and the parameters that underpin selectivity. Understanding the factors that influence the catalytic reactivity of photoexcited metal oxos would constitute enabling technology, with potential applicability to the development of new petrochemical technologies and fuel-forming reactions.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.