Mercury selenide (HgSe; sometimes mercury(II) selenide) is a chemical compound of
mercury and
selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...
. It is a grey-black
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
line solid
semi-metal with a sphalerite structure. The
lattice constant
A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has ...
is 0.608 nm.
HgSe occurs naturally as the mineral
Tiemannite, and is a component of the "intimate mixture" of HgSe and Se known as HgSe
2.
Along with other II-VI compounds,
colloidal nanocrystals of HgSe can be formed.
Applications
* Selenium is used in filters in some steel plants to remove mercury from exhaust gases. The solid product formed is HgSe.
* HgSe can be used as an ohmic contact to wide-gap II-VI semiconductors such as zinc selenide or
zinc oxide
Zinc oxide is an inorganic compound with the Chemical formula, formula . It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, Zinc metabolism, food supplements, rubbe ...
.
Toxicity
Toxic
hydrogen selenide fumes can be evolved on exposure to acids. HgSe is non-toxic as long as it is not ingested due to its insolubility.
HgSe is forms large insoluble clusters with proteins during digestion, and a very precise co-administration of selenium during mercury ingestion has shown to reduce the resulting intoxication. The effect is too finicky for any practical use, but selenium's ability to complex mercury has been proposed to explain why relatively high mercury levels do not intoxicate deep-sea fish.
See also
*
Mercury sulfide
*
Mercury telluride
*
Cadmium selenide
*
Zinc selenide
References
*
*
* .
*
* SNV (1991) Guidelines on measures and methods for heavy metal emissions control. Solna, The Swedish Environmental Protection Agency – Naturvårdsverket.
External links
* https://web.archive.org/web/20051019034837/http://ctdp.ensmp.fr/species/Tiemannite.html
{{DEFAULTSORT:Mercury Selenide
Mercury(II) compounds
Selenides
Zincblende crystal structure