Alkane Oxidation Catalyzed by Mononuclear Non-Heme Iron Complexes

单核非血红素铁配合物催化烷烃氧化

• 批准号: 9818492
• 负责人: Pradip Mascharak
• 金额: $ 39.3万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9818492&HistoricalAwards=false
• 关键词: Alkane; Oxidation; Catalyzed; Mononuclear; Non

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry program supports research on alkane oxidation by Dr. Pradip K. Mascharak of the Chemistry Department, University of California - Santa Cruz. A series of non-porphyrin ligands with biologically relevant donor groups will be synthesized and used to prepare iron complexes that will functionalize C-H bonds. Some of these ligands have been patterned on bleomycin, iron complexes of which have been shown to have monooxygenase activity. A second subset of ligands contains strong field donor groups to stabilize hypervalent iron centers implicated in model complexes. The third subset of ligands can accommodate ligand-based radicals. All the ligands are pentadentate and will afford distorted square pyramidal Fe(II) and Fe(III) complexes that form low spin peroxo Fe(III) complexes when reacted with dioxygen or peroxides. It is this highly oxidizing species that is expected to promote rapid functionalization of alkanes and alkenes under mild conditions. Systematic alteration of ligands will be used to find optimal conditions for oxidation of various alkanes. Reaction rates, product distributions, and stability of the catalytic species will be considered. The reaction pathway will be probed using kinetic isotope effect studies, radical trapping, and stereochemical product analysis. Various spectroscopic techniques (Raman, X-ray, EPR, Mossbauer) will be used to determine the structural and electronic features of the intermediates.The goal of this research is to design new non-heme mononuclear iron complexes that catalyze alkane oxidations and that can also be used to probe the details of the reaction pathways. Alkane oxidation is an important process because methane and other saturated hydrocarbons are abundant and have great potential as starting materials for many essential chemicals, yet are resistant to reaction. Students involved in the project will learn a wide variety of skills in synthesis and instrumental analysis and will gain experience in an interdisciplinary effort that bridges biology and industrial catalyis.

这个无机、生物无机和有机金属化学项目的奖项支持加州大学圣克鲁兹分校化学系的Pradip K. Mascharak博士对烷烃氧化的研究。一系列非卟啉配体与生物相关的供体基团将被合成并用于制备铁配合物，将功能化C-H键。这些配体中的一些已经在博莱霉素上形成了图案，其中的铁配合物已被证明具有单加氧酶活性。第二种配体包含强场给体基团，以稳定模型配合物中涉及的高价铁中心。第三类配体可以容纳基于配体的自由基。所有的配体都是五齿体，当与二氧或过氧化物反应时，会产生扭曲的方形锥体铁（II）和铁（III）配合物，形成低自旋过氧铁（III）配合物。正是这种高氧化性的物质有望在温和的条件下促进烷烃和烯烃的快速官能化。配体的系统改变将用于寻找各种烷烃氧化的最佳条件。反应速率，产物分布和催化物种的稳定性将被考虑。反应途径将通过动力学同位素效应研究、自由基捕获和立体化学产物分析来探索。各种光谱技术（拉曼，x射线，EPR，穆斯堡尔）将被用来确定中间体的结构和电子特征。本研究的目的是设计新的非血红素单核铁配合物，催化烷烃氧化，也可用于探测反应途径的细节。烷烃氧化是一个重要的过程，因为甲烷和其他饱和碳氢化合物丰富，有很大的潜力作为许多基本化学品的原料，但不易发生反应。参与该项目的学生将学习各种各样的合成和仪器分析技能，并将获得连接生物学和工业催化剂的跨学科工作经验。