SusChEM: CAREER: High-Resolution X-ray Spectroscopic Studies of Base Metal Catalysis

有了这个职业奖，化学系的化学结构，动力学机制B计划资助教授凯尔M。康奈尔大学化学和化学生物学系的兰开斯特利用最先进的X射线光谱学来探索地球上丰富的过渡金属催化剂的反应性。 这项研究的目的是确定这些催化剂影响显着的化学转化的机制，包括生物质分解为生物燃料的单糖和天然气转化为可运输的液体形式。了解含有地球上丰富的金属的催化剂的反应性是可持续化学未来的关键。拟议中的工作包括生物化学，合成，光谱学和理论的元素，为本科生和研究生研究人员提供跨学科的培训。构成光谱学基础的光与物质之间的相互作用是本项目下外联工作的基础;具体地说，将为K-12学生开发实用的“实验工具包”，以探索光的性质。正在出现价核X射线发射光谱学、高能量分辨率荧光检测X射线吸收光谱学和共振非弹性X射线散射，表征配位环境和配体电子结构的通用方法。这些方法被用来探测铜催化剂，在这里被定义为酶或配位络合物。待研究的一种这样的催化剂是单核铜酶，其氧化裂解生物质中的多糖，如几丁质和纤维素。停流动力学和快速冷冻淬火方法被用来捕获活性铜氧物种的X射线光谱表征。天然铜催化剂用于甲烷转化为甲醇是本研究的重点。这种催化剂是一种完整的膜蛋白，其活性铜-氧物种通过常规方法无法研究。努力扩展到一个非生物系统：铜催化的有氧醇氧化。这项研究可以证明，所采用的方法并不一定需要精确的知识预催化剂，以表征反应成分。

With this CAREER award, the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division is funding Professor Kyle M. Lancaster of the Department of Chemistry and Chemical Biology at Cornell University to use cutting-edge X-ray spectroscopies to explore the reactivity of earth-abundant transition metal catalysts. The goal of this research is to determine the mechanisms by which these catalysts effect remarkable chemical transformations including the breakdown of biomass to simple sugars for biofuels and the conversion of natural gas to transportable liquid forms. Understanding the reactivity of catalysts incorporating earth-abundant metals is key to a sustainable chemical future. The proposed work incorporates elements of biochemistry, synthesis, spectroscopy, and theory, affording interdisciplinary training for undergraduate and graduate researchers. The interaction between light and matter that forms the basis of spectroscopy is the foundation for outreach efforts under this project; specifically, hands-on "lab kits" are to be developed for K-12 students to explore properties of light.Valence-to-core X-ray emission spectroscopy, high-energy-resolution fluorescence-detected X-ray absorption spectroscopy and resonant inelastic X-ray scattering are emerging, versatile methods to characterize coordination environments and ligand electronic structures. These methods are being used to probe copper catalysts, defined here as either enzymes or coordination complexes. One such catalyst to be studied is a mononuclear copper enzyme that oxidatively cleaves polysaccharides in biomass such as chitin and cellulose. Stopped-flow kinetics and rapid freeze quench methods are being used to trap reactive copper-oxygen species for X-ray spectroscopic characterization. Nature's copper catalyst for conversion of methane to methanol is a focus of this study. This catalyst is an integral membrane protein whose reactive copper-oxygen species have eluded study by conventional methods. Efforts are to be extended to an abiotic system: copper-catalyzed aerobic alcohol oxidation. This study could demonstrate that the methods to be employed do not necessarily require precise knowledge of precatalysts in order to characterize reaction constituents.