Mercury selenide

Mercury(II) selenide
IUPAC name Mercury selenide
Identifiers
CAS number	20601-83-6 Y
Properties
Molecular formula	HgSe
Molar mass	279.55 g/mol
Appearance	grey-black solid
Density	8.3 g/cm3
Melting point	1270 K
Solubility in water	insoluble
Structure
Crystal structure	sphalerite
Thermochemistry
Std enthalpy of formation ΔfHo298	247 kJ/mol
Specific heat capacity, C	178 J kg−1 K−1
Hazards
EU Index	080-002-00-6
EU classification	Very toxic (T+) Dangerous for the environment (N)
R-phrases	R26/27/28, R33, R50/53
S-phrases	(S1/2), S13, S28, S45, S60, S61
Flash point	Non-flammable
Related compounds
Other anions	Mercury oxide Mercury sulfide Mercury telluride
Other cations	Zinc selenide Cadmium selenide
Y selenide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Mercury selenide (HgSe) is a chemical compound of mercury and selenium. It is a grey-black crystalline solid semi-metal with a sphalerite structure. The lattice constant is 0.608 nm.

Mercury selenide can also refer to the following chemical compounds: HgSe₂ and HgSe₈. HgSe is strictly mercury(II) selenide.

HgSe occurs naturally as the mineral Tiemannite.

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.

Toxicity

HgSe is non-toxic so long as it is not ingested due to its insolubility. Toxic hydrogen selenide 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.^[1]

See also

• Mercury sulfide
• Mercury telluride
• Cadmium selenide
• Zinc selenide

References

1. ^ Watanabe, C. (2002). "Modification of Mercury Toxicity by Selenium: Practical Importanc?". The Tohoku Journal of Experimental Medicine 196 (2): 71–77. doi:10.1620/tjem.196.71. PMID 12498318.  edit

• Nelson, D.; Broerman, J.; Paxhia, E.; Whitsett, C. (1969). "Resonant Phonon Scattering in Mercury Selenide". Physical Review Letters 22 (17): 884. doi:10.1103/PhysRevLett.22.884.  edit
• Jayaraman, A.; Klement, W.; Kennedy, G. (1963). "Melting and Polymorphic Transitions for Some Group II-VI Compounds at High Pressures". Physical Review 130 (6): 2277. doi:10.1103/PhysRev.130.2277.  edit
• Gawlik, K. -U.; Kipp, L.; Skibowski, M.; Orłowski, N.; Manzke, R. (1997). "HgSe: Metal or Semiconductor?". Physical Review Letters 78 (16): 3165. doi:10.1103/PhysRevLett.78.3165.  edit.
• Kumazaki, K. (1990). "Dielectric properties of narrow-gap semiconductors". Journal of Crystal Growth 101: 687–690. doi:10.1016/0022-0248(90)91059-Y.  edit
• SNV (1991) Guidelines on measures and methods for heavy metal emissions control. Solna, The Swedish Environmental Protection Agency – Naturvårdsverket.

External links

• http://ctdp.ensmp.fr/species/Tiemannite.html
• List of related Hg chalcogenides