Abstract
Mercury (Hg) is a major global pollutant arising from both natural and anthropogenic sources. Defining the factors that determine the relative affinities of different ligands for the mercuric ion, Hg2+, is critical to understanding its speciation, transformation, and bioaccumulation in the environment. Here, we use quantum chemistry to dissect the relative binding free energies for a series of inorganic anion complexes of Hg2+. Comparison of Hg2+-ligand interactions in the gaseous and aqueous phases shows that differences in interactions with a few, local water molecules led to a clear periodic trend within the chalcogenide and halide groups and resulted in the well-known experimentally observed preference of Hg2+ for soft ligands such as thiols. Our approach establishes a basis for understanding Hg speciation in the biosphere.
Original language | English |
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Pages (from-to) | 2317-2322 |
Number of pages | 6 |
Journal | Journal of Physical Chemistry Letters |
Volume | 4 |
Issue number | 14 |
DOIs | |
State | Published - Jul 18 2013 |
Keywords
- HSAB
- biomagnification
- environmental contamination
- periodic trends
- selenium
- solvation
- speciation