A study of the coordination environment in aqueous cadmium-thiol complexesby EXAFS spectroscopy: experimental vs. theoretical standards

Using EXAFS, we investigated the changes in the local structure of Cd(II) c omplexes formed with a series of low-molecular-weight thiols at different t hiol/cadmium stoichiometries. For dilute solutions, a comparison of theoret ical and experimental standards proved the latter approach superior. The nu mber of bound oxygen atoms decreased while the number of sulfur atoms incre ased as the thiol/cadmium ratios increased, indicating that up to four thio l compounds can bind to cadmium in aqueous solutions. The computer code FEF FIT was modified to employ experimental and theoretical standards with equa l facility.