The Molecular Structure of Aqueous Hg(II)-EDTA As Determined by X‑ray Absorption Spectroscopy
journal contributionposted on 26.03.2015, 00:00 by Sara A. Thomas, Jean-François Gaillard
The widespread presence and persistence of ethylenediaminetetraacetic acid (EDTA) in aquatic environments can lead to the formation of metal–EDTA complexes that influence metal bioavailability and mobility. Recently, the Hg(II)-EDTA complex was observed to slightly promote the biouptake of Hg(II) to the bacterium Escherichia coli and to undergo a relatively quick ligand exchange reaction with thiols at the bacterial cell membrane. The reactivity of a metal complex depends on its molecular structure; however, the molecular structure of aqueous Hg(II)-EDTA has yet to be reported. Here, we use X-ray absorption spectroscopy to determine the molecular structure of aqueous Hg(II)-EDTA. Our results suggest that aqueous Hg(II)-EDTA displays distorted octahedral geometry with one water molecule in the coordination sphere.