Metal Sulfur Complexes in Marine Waters

小行星9314349 在缺氧和硫化物环境中痕量金属的浓度是由金属硫化物相的沉淀以及硫化物和其他硫物质对金属的络合作用控制的。 将确定各种具有环境意义的金属与硫化物、硫代硫酸盐和多硫化物的稳定常数。 通过伏安法使用硫物质和/或金属的峰获得常数。 这项研究还需要用酸和碱滴定络合物，以确定附着在硫物质上的质子数。这项工作将建立在海水中的初步工作，这表明，铁（II）和硫化物形成两个络合物，这是Fe（SH）+（log B=5.5）和Fe 2（SH）3+（log B= 11.1）。 这些 常数的数量级高于通过线性自由能关系估算的常数。 事实上，Fe 2（SH）3+并没有通过这种或任何使用硫化物作为滴定剂的实验方法预测。 因此，铁（II）在缺氧界面和硫化物环境中的溶解度可以提高比以前的估计。

9314349 LUTHER The concentration of trace metals in anoxic and sulfidic environments is controlled by the precipitation of metal sulfide phases as well as the complexation of the metals by sulfide and other sulfur species. Stability constants of a variety of metals of environmental significance with sulfide, thiosulfate and polysulfides will be determined. The constants will be obtained by voltammetric methods using the peaks of the sulfur species and/or the metal. The research also requires titrations of the complexes with acid and base to determine the number of protons attached to the sulfur species. This work will build on initial work in seawater which shows that iron (II) and sulfide form two complexes which are Fe(SH)+ (log B=5.5) and Fe2(SH)3+ (log B= 11.1). These constants are orders of magnitude higher than constants evaluated by linear free energy relationships. In fact, Fe2(SH)3+ was not predicted by this or any experimental approach which uses sulfide as a titrant. Thus, Fe(II) solubility at anoxic interfaces and in sulfidic environments can be enhanced over previous estimates.