SusChEM: Extending organochromium chemistry - stable alkyl hydrides and high-valent alkylidenes

化学学部化学催化项目支持Klaus Theopold教授的项目。Theopold教授是特拉华大学化学和生物化学系的教员。他正在把铬的有机金属化学扩展到以前未探索的方向。这个项目的一部分旨在探索简单碳氢化合物的碳氢键的活化。碳(C)-氢(H)键的活化和功能化是一个重大挑战，为合成有用的有机分子提供了机会。该项目的另一部分探索了铬烷基烷在该金属的最高氧化态（VI）下的反应性。这种分子是罕见的，它们催化转化的潜力在这项工作之前是未知的。因此，该研究项目正在揭示有助于现代合成有机化学的新的催化反应途径。这项工作处于无机化学和有机化学的交叉点。其广泛的覆盖面旨在培养各级合成化学家。Theopold教授的外展活动包括担任高中科学博览会的评委，为富兰克林研究所（宾夕法尼亚州费城的一家科学博物馆）做志愿者工作，以及为科学、技术、工程和数学专业的普通化学课程出版教科书。先前在Theopold实验室的工作已经发现了几种异常稳定的双核铬烷基氢化物，它们的类型为LCr(mu-R)(mu-H)CrL，它们可能被视为碳氢化合物C-H活化的产物，反过来又参与简单碳氢化合物的C-H活化反应。该项目的一部分是确定合成路线，以制备和结构表征更广泛的此类化合物。这项研究有助于检验它们的相对稳定性和反应性。该计划还包括研究它们与碳氢化合物反应的机制，导致烷基交换。在铬化学的另一个扩展中，制备了一种稀有的烷基化铬并确定了其结构。本项目涉及合成（ArN）2Cr(VI)=CHR型烷基烷。这些异常高价化合物的反应性以前还没有被详细研究过。潜在的催化应用包括烯烃的分解和聚合。通过相关的DFT计算扩充了综合工作。Theopold教授的研究小组是多元化的，并为在科学领域代表性不足的学生和残疾学生提供教育机会。

The Chemical Catalysis Program of the Chemistry Division supports the project by Professor Klaus Theopold. Professor Theopold is a faculty member in the Department of Chemistry and Biochemistry at the University of Delaware. He is extending the organometallic chemistry of chromium in previously unexplored directions. One part of this project aims to explore the activation of carbon-hydrogen bonds of simple hydrocarbons. The activation and functionalization of carbon (C)-hydrogen (H) bonds is a significant challenge and offers opportunities for the synthesis of useful organic molecules. The other part of this project explores the reactivity of chromium alkylidenes in the highest possible oxidation state (VI) of that metal. Such molecules are rare and their potential for catalytic transformation were unknown prior to this work. Accordingly, the research project is uncovering new catalytic reaction pathways that aid modern synthetic organic chemistry. The work lies at the interface of inorganic and organic chemistry. Its broad reach is designed to train synthetic chemists at all levels. Professor Theopold's outreach activities include service as judge for a high school science fair, volunteer work for the Franklin Institute, a science museum in Philadelphia, PA, and the publication of a textbook for General Chemistry courses for Science, Technology, Engineering and Mathematics majors. Previous work in the Theopold laboratory has led to the discovery of several unusually stable dinuclear chromium alkyl hydrides of the type LCr(mu-R)(mu-H)CrL, which may be seen as products of the C-H activation of hydrocarbons, and which in turn engage in C-H activation reactions of simple hydrocarbons. One part of the project is to identify synthetic routes for the preparation and structural characterization of a wider range of such compounds. This study facilitates an examination of their relative stability and reactivity. The program also includes investigations of the mechanism of their reaction with hydrocarbons, leading to alkyl group exchange. In another extension of chromium chemistry, a rare chromium alkylidene has been prepared and its structure determined. This project involves the synthesis of alkylidenes of the type (ArN)2Cr(VI)=CHR. The reactivity of these unusually high-valent compounds has not previously been explored in any detail. Potential catalytic applications involve olefin metathesis and polymerization. The synthetic work is augmented by relevant DFT calculations. Prof. Theopold's research group is diverse and offers educational opportunities to students underrepresented in science fields and students with disabilities.