Molecular Mechanisms of Bacterial Mercury Transformation

doi:10.2172/1127445

GSTDTAP > 地球科学

DOI	10.2172/1127445
报告编号	DOE-TENN-4895
来源ID	OSTI ID: 1127445
	Molecular Mechanisms of Bacterial Mercury Transformation
	smith, jeremy
	2014-04-15
出版年	2014
语种	英语
国家	美国
领域	地球科学
英文摘要	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 used quantum chemistry to dissect the relative binding free energies for a series of inorganic anion complexes of Hg2+. The results show that, whereas in the gas phase the binding affinity of two identical anionic ligands (forming HgL2) increases with ligand (Lâ) hardness, in contrast, in the aqueous phase the affinity increases with ligand softness. This switch in affinity upon hydration is shown to result mostly from interactions with only a small number (e.g. one or two) of water molecules. The results yield a clear, robust periodic trend within the chalcogenide and halide groups and are in agreement with the well-known experimentally observed preference of Hg2+ for soft ligands. By comparing the Hg2+ binding of one with two anions, the gas phase preferences are found to arise from the enhancement of reactivity of the cationic complex (HgL+) with the hardness of Lâ. The approach establishes a theoretical basis for understanding Hg speciation in the biosphere.
英文关键词	mercury computational science
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来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/6627
专题	地球科学
推荐引用方式 GB/T 7714	smith, jeremy. Molecular Mechanisms of Bacterial Mercury Transformation,2014.