Kinetics and Mechanisms of Main-Group Reactions

本项目由无机、生物无机和有机金属化学计划资助。它的重点是水溶液中主要基团无机反应的动力学和机理。将使用止流法（单波长、快速扫描和电导率检测）获得动力学数据。停止缓慢的数据将用于获得速率常数，反应速率定律和化学计量。研究的反应包括：1)选择主基团氧化还原对之间的电子转移反应，为Marcus理论在离子半径差异很大的物质之间的反应的适用性提供严格的检验；2)氯/二氯、溴/二溴、羟胺/羟胺和NO/NO-作为氧化还原对的电子转移反应，反应伙伴为取代惰性配位配合物，得到主基团对的标准氧化还原电位和有效自交换速率常数；3)二亚胺的二氢转移（现在有方法生成和检测该物种），重点是与二氧、二碘和过氧化氢以及与烯烃和单电子氧化剂的反应；4)亚硫酸盐被四氯酸盐（III）和其他配位配合物氧化的球内反应，探索导致二硫酸盐中S-S键形成的机制因素；5)一氧化氮与二氧的反应和三氧化硫与水的反应，因为它们与环境问题相关。含有所谓的主族元素的分子的反应，如氮、硫、氯和溴，在工业和日常生活中非常重要，例如饮用水的净化和家用洗衣机中氯漂白剂的作用。除了更好地了解这些常见反应中有多少会发生外，该项目的结果还可能有助于了解如何避免有害的副反应，例如在污水处理厂废水氯化过程中致癌物质的形成。

This project is supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program. Its focus is the kinetics and mechanisms of main-group inorganic reactions in aqueous solution. Stopped-flow methods (with single wavelength, rapid scan and conductivity detection) will be used to obtain kinetic data. The stopped-slow data will be used to obtain rate constants, reaction rate laws and stoichiometries. Reactions to be studied include: 1) Selected electron transfer reactions between pairs of main-group redox couples, in order to provide stringent tests of the applicability of Marcus theory to reactions between species of widely differing ionic radii; 2) electron transfer reactions involving chlorine/dichloride, bromine/dibromide, hydroxylammonium/hydroxylamine, and NO/NO- as redox couples, where the reaction partners are substitution-inert coordination complexes, leading to standard redox potentials and effective self-exchange rate constants for the main-group couples; 3) dihydrogen transfer from diimide (now that methods are available to generate and detect this species) with emphasis on reactions with dioxygen, diiodine and hydrogen peroxide, as well as with olefins and one-electron oxidants; 4) inner-sphere reactions in which sulfite is oxidized by tetrachloroaurate(III) and other coordination complexes, probing the mechanistic factors that lead to formation of the S-S bond in dithionate; 5) the reactions of NO with dioxygen and of sulfur trioxide with water, because of their relevance to environmental issues. %%% Reactions of molecules containing the so-called main-group elements, such as nitrogen, sulfur, chlorine and bromine, are of great importance in industry and in everyday life, with examples including the purification of drinking water and the action of chlorine bleach in the home washing machine. In addition to providing a better understanding of how many of these common reactions occur, the results of this project may provide insight into how to avoid detrimental side reactions, such as the formation on carcinogens during the chlorination of sewage plant effluents.