Singlet Oxygen with Metal Thiolates and Arylphosphines

单线态氧与金属硫醇盐和芳基膦

• 批准号: 7255717
• 负责人: MATTHIAS SELKE
• 金额: $ 12.38万
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7255717
• 关键词: adduct; catalyst; chemical stability; chemical structure function; chemical synthesis; cysteine; electrical property; hydrogen ions; intermolecular interaction; ligands; metalloenzyme; methionine; nuclear magnetic resonance spectroscopy; organometallic compounds; oxidation reduction reaction; peroxides; phosphines; singlet oxygen; spectrometry; thiols

The chemistry of singlet oxygen with organometallic compounds and arylphosphines will be explored. Very little research has been accomplished in this area. The basic aims are twofold: (i) To solve a number of fundamental mechanistic questions in oxidation chemistry, and (ii) to find new oxidants derived from the most benign oxidant, i.e. dioxygen. Reactive intermediates in oxygen chemistry are often difficult to detect because they themselves are powerful oxidants. We are trying to find new methods (using singlet dioxygen) to observe and possibly isolate such species and, where applicable, to investigate their potential as oxidants. Specifically, the chemistry of singlet oxygen with metal thiolates, especially S-bound cysteine will be investigated. We will explore the diverse reaction pathways such as formation of sulfenate, sulfinate, C-S bond cleavage or oxidative addition at the metal center. We will determine factors (oxidation state of metal, protic vs. aprotic environment, sterics) that determine the susceptibility of such thiolates toward oxidative damage. Thiolate ligands often serve as bridges in multinuclear complexes, and the chemistry of such species with singlet oxygen will be explored as well. Both ligand oxidation and reaction of dioxygen at the metal center are possible reactive pathways in such systems. We will address the fundamental question of how oxidation at the first metal affects reactivity at the second metal center. We will also investigate the chemistry of singlet oxygen with arylphosphines. Despite the well-known affinity of trivalent phosphorous for oxygen, there have been no previous studies of the chemistry of arylphosphines with singlet oxygen, and intermediates in the oxidation of phosphines by singlet oxygen have never been directly observed. We are planning to study these intermediates and use them as a novel "oxene"-like class of oxygen atom transfer agents.

将探索单线态氧与有机金属化合物和芳基膦的化学反应。这方面的研究还很少。其基本目标有两个：（i）解决氧化化学中的一些基本机理问题，以及（ii）从最良性的氧化剂（即双氧）中寻找新的氧化剂。氧化学中的反应中间体通常难以检测，因为它们本身就是强氧化剂。我们正在尝试寻找新方法（使用单线态双氧）来观察并可能分离这些物种，并在适用的情况下研究它们作为氧化剂的潜力。 具体来说，将研究单线态氧与金属硫醇盐，特别是S-结合半胱氨酸的化学反应。我们将探索多种反应途径，例如次磺酸盐的形成、亚磺酸盐、C-S键断裂或金属中心的氧化加成。我们将确定决定此类硫醇盐对氧化损伤的敏感性的因素（金属的氧化态、质子与非质子环境、空间）。硫醇盐配体通常充当多核配合物中的桥梁，并且还将探索此类物质与单线态氧的化学反应。配体氧化和金属中心分子氧的反应都是此类系统中可能的反应途径。我们将解决第一个金属的氧化如何影响第二个金属中心的反应性的基本问题。我们还将研究单线态氧与芳基膦的化学反应。尽管三价磷与氧的亲和力众所周知，但以前没有对芳基膦与单线态氧的化学进行研究，并且从未直接观察到单线态氧氧化膦的中间体。我们计划研究这些中间体并将它们用作新型“oxene”类氧原子转移剂。