Studies on the Chemistry of Platinum Group Element Complexes Relating to Catalysis

化学部无机、生物无机和金属有机化学项目支持罗切斯特大学化学系Richard Eisenberg博士研究与均相催化和键激活有关的铂族元素络合物的化学。该项目的第一部分是一系列的机理研究，涉及对氢诱导极化(PhIP)在新的有机金属体系中的应用。这种方法可以检测到新的氢化物中间体，并有助于阐明氢加成的机理。将研究通过氧化加成到各种金属中心来激活氢，包括能够在分子内激活C-H和C-C的Rh和Ir络合物以及早期过渡金属氢化物。还将研究亚烷基、亚烷基、亚胺和硫化物中的金属-非金属多键与氢的加成反应，为协同四中心加成提供证据。PhIP将研究的催化反应包括不对称氢化和氢甲酰化。该项目的第二部分重点介绍了具有亲电或自由基特性的有机金属体系的键活化和催化反应。将合成Ir(III)的阳离子双膦配合物和具有特殊设计的四齿配体的配合物。这些络合物将有两个相邻的不稳定位点，用于底物结合、活化和偶联。还将研究铂和钯与新的二亚胺和二胺配体的相关亲电络合物。这些和相关的络合物将在H/D交换、异构化、C-H键活化和烯烃聚合等反应中进行反应性筛选。新的d7Rh(II)和Ir(II)希夫碱配合物将研究奇电子配合物对键的活化作用，其中含有四齿N和S给体配体。将被最广泛研究的金属反应是那些涉及甲烷、甲苯、烷烃和zylen的C-H活化以及自由基驱动聚合的反应。将开展与均相催化和键活化有关的铂族元素化合物化学的研究计划。铂族元素络合物是当今工业上使用最广泛的催化剂，过去十年的发展，特别是在不对称催化和聚合催化方面的发展表明，这种作用在未来将会增加。该项目将促进我们对发生在金属上的根本性变化的理解，并将有助于为化工和制药行业设计新的重要催化剂。

The Inorganic, Bioinorganic and Organometallic Chemistry Program of the Chemistry Division is supporting Dr. Richard Eisenberg, Chemistry Department, University of Rochester, for research on the chemistry of platinum group element complexes relating to homogeneous catalysis and bond activation. Part one of the project is a series of mechanistic studies involving applications of parahydrogen induced polarization (PHIP) to new organometallic systems. This method can permit the detection of new hydride intermediates and may help elucidate the mechanism of hydrogen addition. The activation of hydrogen by oxidative addition to a variety of metal centers will be investigated, including rhodium and iridium complexes capable of intramolecular C-H and C-C activation and early transition metal hydrides. The addition of hydrogen to metal-nonmetal multiple bonds contained in alkylidene, alkylidyne, imido and sulfido complexes will also be studied in an effort to provide proof for a concerted 4-center addition. Catalytic reactions that will be investigated by PHIP include asymmetric hydrogenation and hydroformylation. Part two of the project focuses on the bond activation and catalytic reactions of organometallic systems that exhibit electrophilic or radical character. Cationic diphosphine complexes of Ir(III) and complexes with specifically designed tetradentate ligands will be synthesized. These complexes will have two adjacent labile sites for substrate binding, activation, and coupling. Related electrophilic complexes of Pt and Pd with new diimine and diamine ligands will also be studied. These and related complexes will be screened for reactivity in reactions that include H/D exchange, isomerizations, C-H bond activation, and olefin polymerization. Bond activation by odd electron complexes will be studied with new d7 Rh(II) and Ir(II) Schiff base complexes that contain tetradentate N and S donor ligands. The metalloradical reactions that will be studied most extensively are those involving C-H activation of methane, toluene, alkanes, and zylenes, and radical driven polymerizations. A program of research on the chemistry of platinum group element compounds relating to homogeneous catalysis and bond activation will be conducted. Platinum group element complexes include the most widely used catalysts in industry today, and developments in the past decade, particularly with regard to asymmetric catalysis and polymerization catalysis, suggest that this role will increase in the future. This program will advance our understanding of the fundamental transformations that take place at the metal and will help in the design of new important catalysts for the chemical and pharmaceutical industry.