UNDERSTANDING METAL MEDIATED C-H AND O-H BOND OXIDATIONS

拟议的研究将提供基本的了解如何 过渡金属络合物和活性位点氧化C-H和O-H键。 这种化学过程发生在广泛的生物系统中， 从脂肪氧合酶的脂肪酸氧化到 照相系统II.许多这些金属酶和相关系统都具有 已经被单独详细研究过，但对 它们的基本化学反应性是它们的基础。通过研究一系列 模型化合物和模型反应，一个基本的和预测的 理解正在发展。 涉及氢原子转移的反应是本领域的主要焦点。 描述的研究。速率常数与 热力学驱动力将扩展到新的系统， 更广泛的底物，包括酚类。驾驶以外的因素 力将被探测。有机自由基化学和马库斯 电子转移理论将被用来提供见解。的想法 在氢转移反应的这种发展范例的基础上， 将适用于其他氧化机制，特别是氢化物 转移过程。 拟议的工作包括机制和综合研究。 氧化配位络合物或铁，锰，铜， 钌将被制备并检测它们的反应。这些复合物 是氧化酶如脂氧合酶的功能模型， 多巴胺β-单加氧酶。通过研究碳氢化合物的氧化， 酚类和其他底物，同时测量氧化还原 电位，pK/a值和自交换率，我们将生成一个 了解这些反应，更一般地说，金属如何介导 生物化学系统中质子和电子的耦合运动 本案无关

The proposed research will provide fundamental understanding of how transition metal complexes and active sites oxidize C-H and O-H bonds. Such chemical processes occur in a wide range of biological systems, from fatty acid oxidations by lipoxygenases to oxygen evolution by photo-system II. Many of these metalloenzymes and related systems have been individually studied in detail, but there is limited knowledge of their basic chemical reactivity underlies them. By studying a range of model compounds and model reactions, a fundamental and predictive understanding is being developed. Reactions that involve transfer of a hydrogen atom are a major focus of the studies described. The correlations of rate constants with thermodynamic driving force will be extended to new systems and with a wider range of substrates, including phenols. Factors other than driving force will be probed. Both organic radical chemistry and the Marcus theory of electron transfer will be used to provide insights. The ideas underlying this developing paradigm for hydrogen tom transfer reactions will be applied to other oxidation mechanisms, especially hydride transfer processes. The proposed work includes both mechanistic and synthetic studies. Oxidizing coordination complexes or iron, manganese, cooper, and ruthenium will be prepared and their reactions examined. These complexes are functional models for oxidizing enzymes such as lipoxygenase and dopamine beta-monooxygenase. By studying the oxidations of hydrocarbons, phenols, and other substrates in parallel with measurements of redox potentials, pK/a values, and self exchange rates, we will generate an understanding these reactions and, more generally, how metals mediate the coupled movement of protons and electrons in systems of biochemical relevance.