Kinetics and Mechanisms of Main-Group Reactions

该项目得到了无机化学、生物无机化学和金属有机化学计划的支持。重点研究了水溶液中主基无机反应的动力学和机理。将使用停流法(单波长、快速扫描和电导检测)来获得动力学数据。慢停数据将被用来获得速率常数、反应速率定律和化学计量。要研究的反应包括：1)选择主基团氧化还原对之间的电子转移反应，以严格检验Marcus理论对离子半径相差很大的物种之间的反应的适用性；2)电子转移反应，包括氯/二氯化物、溴/二溴、羟胺/羟胺和NO/NO-作为氧化还原对，其中反应伙伴是取代惰性配位络合物，导致主基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(现在已经有了生成和检测这种物种的方法)，重点是与氧气、二碘和过氧化氢的反应，以及与烯烃和单电子氧化剂的反应；4)亚硫酸盐被四氯金酸盐(III)和其他配位络合物氧化的内球反应，探讨了导致二硫酸盐中S-S键形成的机理因素；5)NO与二氧化氧和三氧化硫与水的反应，因为它们与环境问题有关。含有氮、硫、氯和溴等所谓主族元素的分子的反应在工业和日常生活中非常重要，举例包括饮用水的净化和氯漂白剂在家用洗衣机中的作用。除了更好地了解这些常见反应中有多少会发生之外，该项目的结果还可能为如何避免有害的副反应提供洞察，例如在污水处理厂废水的氯化过程中形成致癌物质。

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.