Mercury selenide (HgSe; sometimes mercury(II) selenide) is a chemical compound of
mercury and
selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...
. 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, macro ...
line solid
semi-metal
A semimetal is a material with a very small overlap between the bottom of the conduction band and the top of the valence band.
According to electronic band theory, solids can be classified as insulators, semiconductors, semimetals, or metals. ...
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 o ...
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 formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement ...
.
Toxicity
HgSe is non-toxic as long as it is not ingested due to its insolubility. Toxic
hydrogen selenide
Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic sel ...
fumes can be evolved on exposure to acids. HgSe is a relatively stable compound which might mean that it is less toxic than elemental mercury or many organometallic mercury compounds. Selenium's ability to complex with mercury has been proposed as a reason for the lack of mercury toxicity in deep sea fish despite high mercury levels.
See also
*
Mercury sulfide
Mercury sulfide, or mercury(II) sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS. It is virtually insoluble in water.
Crystal structure
HgS is dimorphic with ...
*
Mercury telluride
Mercury telluride (HgTe) is a binary chemical compound of mercury and tellurium. It is a semi-metal related to the II-VI group of semiconductor materials. Alternative names are mercuric telluride and mercury(II) telluride.
HgTe occurs in nature ...
*
Cadmium selenide
Cadmium selenide is an inorganic compound with the formula Cd Se. It is a black to red-black solid that is classified as a II-VI semiconductor of the n-type. Much of the current research on this compound is focused on its nanoparticles.
Stru ...
*
Zinc selenide
Zinc selenide (ZnSe) is a light-yellow, solid compound comprising zinc (Zn) and selenium (Se). It is an intrinsic semiconductor with a band gap of about 2.70 eV at . ZnSe rarely occurs in nature, and is found in the mineral that was named af ...
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