Mechanistic Chemistry of Transition Metal Oxygen and Oxo Complexes

该奖项在无机，生物无机和有机化学 该计划将支持詹姆斯·H博士的工作Espenson和Andreja 爱荷华州州立大学化学系的Bakac说， 过渡金属介导的氧化反应。 许多 研究将探索超氧铬（III）离子，这是 当Cr（II）与氧反应时迅速形成。 相关Aqua Cr、W和Mo的大环络合物将被 表征以确定氧结合模式。 离子的氧自交换机制将是 使用放射性标记方法测定。 氧传递 Ru、Rh和Cr与其它过渡金属氧代之间的反应 将研究受体。 此外，快速 其他低价过渡金属离子与氧的反应 将被研究，这些反应的机理 测定 金属-氧代、金属-过氧或金属-超氧 可以预期复合物作为中间体被观察到。 将讨论所形成的金属-氧代络合物的各种反应。 进行，包括电子转移和氢 抽象 %%% 在这场对细节的彻底调查中， 一些过渡金属离子与氧，Espenson和 Bakac将决定氧与金属结合的方式， 氧气与其他气体交换的速率和途径 金属，以及金属-氧代络合物对 氧化或还原。 基本成果在预期之中 有助于理解过渡金属在 有机氧化反应，在工业上是重要的， 以及生物系统中的金属氧离子。

This award in the Inorganic, Bioinorganic, and Organometallic Program will support work by Drs. James H. Espenson and Andreja Bakac of the Chemistry Department, Iowa State University, on transition metal-mediated oxidation reactions. Many of the studies will explore the superoxochromium(III) ion, which is quickly formed when Cr(II) reacts with oxygen. Related aqua and macrocyclic complexes of Cr, W, and Mo will be characterized in order to determine the oxygen binding mode. The mechanism of oxygen self-exchange of the ion will be determined using radioactive labeling methods. Oxygen transfer reactions between Ru, Rh, and Cr and other transition metal oxo acceptors will be studied. In addition, the very rapid reactions of other low-valent transition metal ions with oxygen will be investigated and the mechanism of those reactions determined. Metal-oxo, metal-peroxo, or metal-superoxo complexes might be expected to be observed as intermediates. Various reactions of the metal-oxo complexes formed will be undertaken, including electron transfer and hydrogen abstraction. %%% In this thorough investigation of the details the interaction of a number of transition metal ions with oxygen, Espenson and Bakac will determine the way oxygen binds to the metal, the rates and pathways by which oxygen is exchanged with other metals, and the susceptibility of the metal-oxo complexes to oxidation or reduction. The fundamental results are expected to be helpful in understanding the role of transition metals in organic oxidation reactions, which are industrially important, and of metal-oxo ions in biological systems.