Computational characterization of organic ligands derived from fumaric acid for selective adsorption of inorganic mercury

Abstract

By means of electronic structure calculations, the interaction mechanisms between Hg2+ and organic ligands of fumaric acid functionalized with -SH, -SCH3, -NH2 and -PH2 groups were evaluated. Waters contaminated with mercury are a risk to the living beings that depend on these environments, being necessary to develop methods of capture and to identify the chemical species containing mercury. Functionalized organic compounds can be used in the remediation of waters or as constituents of metal−organic networks that adsorb the metal. Interaction energy analysis (in gas phase and including solvent effect), as well as global reactivity indices suggest that the tiol functionalization is a selective group to mercury compared to other water constituent metals. Through analysis of charge transfer and the index of non-covalent interactions it was verified that such adsorption was mediated by the coordination of mercury with an oxygen atom and the sulfur of the thiol group, and that these interactions are strong and non-dispersive.