oa Reactivity of Hydrogen Sulfide Toward Organic Compounds with Sulfur-Sulfur Bonds

Organic compounds which contain sulfur-sulfur bonds were found in the waters and sediments of the natural aquatic systems as well as in the fossil fuels. Processes leading to formation of these compounds were intensively studied during the last decades. On the other hand, kinetics, mechanisms and products of reactions which lead to their decomposition are poorly studied. The main goal of this research is a determination of kinetic parameters of reactions between deprotonated form pf hydrogen sulfide, bisulfide anion, with organic compounds containing S-S bonds as well as determination of products and mechanisms of these reactions. It was found that organic polysulfides react with bisulfide anion rather than with hydrogen sulfide. Products of the reaction between dimethyl polysulfides and bisulfide anion include methane thiol, higher and lower dimethyl polysulfides and inorganic polysulfides. Under the environmental conditions, decomposition of aliphatic organic compounds with sulfur-sulfur bonds in the presence of bisulfide anion takes place in minutes to hundreds of years, e.g., at similar or higher rates than sulfurization of organic matter. This implies that the formation of organic compounds with sulfur-sulfur bridges under sulfidic conditions by a reaction of sedimentary organic matter with inorganic polysulfides is inevitably accompanied by their decomposition.