Polynuclear Transmetalation Reactions and Products

该奖项由无机、生物无机和有机金属化学项目颁发，研究领域为过渡金属化学。该项目关注的是两种不同金属的原子在它们附着的载体分子之间交换的反应，即所谓的金属转化反应。特别令人感兴趣的是涉及多金属物种的反应，这些物种在一个分子中含有几个金属原子。该项目的目的之一是利用金属转化反应合成一个分子中含有两种或两种以上不同金属原子的多金属物种。这样的混合金属多金属物种有望具有有趣的催化性质，也是重要酶的模型，如呼吸酶细胞色素氧化酶。也有可能将混合金属分解成不能直接由组成金属制成的合金。该项目的重点将是新发现的金属转化现象，这种现象导致多金属靶中的金属中心被简单分子金属转化物中的其他金属定量地、逐步地取代。反应在温和的条件下进行，产物容易分离。主要研究内容为：1)阳离子靶和转金属产物的分离、结构表征和电化学研究；2)早期重元素嬗变系统的研究；3)开发和使用更经济的变性器；4)鉴定产生大多金属分子的连锁变金属反应；5)杂多金属分子的选择性配体化学描述；6)利用金属转化制备新的大块合金和负载金属催化剂；杂多有机金属化学的发展。

This award from the Inorganic, Bioinorganic and Organometallic Chemistry Program is in the area of transition metal chemistry. The project is concerned with reactions in which atoms of two different metals are exchanged between carrier molecules to which they are attached, so-called transmetalation reactions. Of particular interest are reactions involving polymetallic species, species which contain several metal atoms within one molecule. One aim of the project is to use transmetalation reactions to synthesize polymetallic species containing atoms of two or more different metals within one molecule. Such mixed-metal polymetallic species are expected to have interesting catalytic properties and also are models of important enzymes, such as the respiratory enzyme cytochrome oxidase. It may be possible also to decompose the mixed-metal species to yield alloys of types which cannot be made directly from the constituent metals. The focus of the project will be the newly discovered phenomenon of transmetalation which leads to quantitative, stepwise replacement of metal centers in polymetallic targets by other metals from simple molecular transmetalators. The reactions proceed under mild conditions and the products are easily separated. The major components of the research will be: 1) isolation, structural characterization and electrochemical studies of cationic targets and transmetalation products; 2) investigation of earlier and heavier element transmetalation systems; 3) development and use of more economical transmetalators; 4) identification of reactions of linkage transmetalators which give large polymetallic molecules; 5) description of the selective ligand chemistry of heteropolymetallic molecules; 6) use of transmetalation to generate new bulk alloys and supported metal catalysts; and 7) development of heteropolyorganometallic chemistry.