Polynuclear Transmetalation Reactions and Products

该奖项由无机化学、生物无机化学和有机金属化学计划颁发，涉及过渡金属化学领域。该项目关注的是两种不同金属的原子在它们所连接的载体分子之间交换的反应，即所谓的转金属反应。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包含几个金属原子。该项目的一个目标是利用转金属反应来合成在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。这种混合金属多金属物种有望具有有趣的催化性能，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转金属现象，这种现象导致多金属靶中的金属中心被简单分子转金属中的其他金属定量、逐步地取代。反应在温和的条件下进行，产物很容易分离。这项研究的主要内容包括：1)阳离子靶标和转金属产物的分离、结构表征和电化学研究；2)早期和较重元素转金属体系的研究；3)开发和使用更经济的转金属化合物；4)鉴定得到大分子多金属分子的连接转金属化合物的反应；5)描述了杂多金属分子的选择性配体化学；6)利用过渡金属作用生成了新的块状合金和负载型金属催化剂；7)发展了杂多金属有机化学。

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.