Lewis Acids: Electron Transfer Reagents

在有机动力学项目的支持下，詹森博士将研究金属离子催化的有机物质与水的反应，以此来确定金属离子在各种络合状态下的反应行为。无论是从工业/经济角度还是从生物学角度来看，金属离子在对我们的生活质量至关重要的化学过程中起着至关重要的作用。通过探索金属离子反应性对金属络合状态的依赖性而获得的信息有望应用于环境问题(例如，与环境中有机化合物的解毒有关的问题和新化学转化的发展。已经证明，当反应在能够络合汞离子的阴离子存在下进行时，汞（II）离子促进O， s -缩醛水解的能力大大降低。该项目旨在澄清重金属离子在此类反应中的作用，即，金属是否只是作为路易斯酸起作用，或者与O， s -缩醛等反应是否通过电子转移到重金属离子中涉及硫的氧化？将水解促进试剂从路易斯酸试剂转变为电子转移试剂的影响将通过涉及各种过渡金属的高氧化态金属配合物的动力学研究来探讨。快速反应动力学（即止流）技术将被用于检测氧化硫物质的积聚，这种物质假定发生在电子转移介导的O， s -缩醛分解之前。

With support from the Organic Dynamics Program, Dr. Jensen will study metal ion catalyzed reactions of organic substances with water as a means to determine the reactive behavior of metal ions in various states of complexation. Metal ions play a vital role in the chemical processes essential to our quality of life, both from an industrial/economic viewpoint as well as from a biological perspective. Information gained via exploration of the dependence of metal ion reactivity on the state of metal complexation is expected to have application to environmental problems (e.g., problems related to detoxification of organomercurials in the environment) and to the development of new chemical transformations. It has been shown that the ability of mercury(II) ions to promote hydrolysis of O,S-acetals is greatly diminished when the reaction is performed in the presence of anions that are capable of complexing this ion. The project seeks to clarify the role of the heavy metal ion in such reactions, i.e., does the metal simply function as a Lewis acid, or does the reaction with, e.g., O,S-acetals involve oxidation of sulfur via electron transfer to the heavy metal ion? The effect of changing the hydrolysis-promoting reagent from a Lewis acid reagent to an electron transfer reagent will be probed via kinetic studies that involve high oxidation state metallocomplexes of a variety of transition metals. Fast reaction kinetic (i.e., stopped-flow) techniques will be utilized to detect build-up of oxidized sulfur species that is postulated to occur prior to decomposition of the O,S-acetal in electron transfer mediated processes.