Much current research is directed toward understanding the behavior of trace metals in anoxic aquatic environments. These studies have created a need for accurate data on the stoichiometry and stability of metal complexes containing reduced sulfur ligands. Existing data in many cases are uncertain at the order of magnitude level. In other cases, no data whatever are available (e.g., polysulfide and aliphatic thiol complexes of most sulfophile trace metals). A major question about such data as do exist concerns whether the complexes are mononuclear or poly- nuclear. Previous experimentalists have raised this question but not answered it. Misinterpretation of polynuclear complexes as mononuclear can create immense errors in predictions of chemical behavior in nature. A program to make the fundamental measure- ments is needed to answer such questions. Copper and zinc will be the focus of most of the work, although some studies on Fe will be undertaken if time permits. All measurements will be made at 250C. These studies will build upon previous work in this laboratory. They will add significant information in deciphering metal solubility in anoxic environments with applications to pollution, waste water treatment and a variety of geochemical problems.
