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.
