Chemistry:Sodium selenide

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Sodium selenide
Na2Se-powder.jpg
Sodium-selenide-unit-cell-1992-CM-3D-balls.png
Names
IUPAC name
sodium selenide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
EC Number
  • 215-212-0
UNII
Properties
Na2Se
Molar mass 124.951 g·mol−1
Density 2.62 g cm−3[1]
Melting point >875 °C
reacts with water
Structure[2]
Cubic (fluorite), cF12
Fm3m, No. 225
a = 0.6825 nm
4
Hazards
GHS pictograms GHS06: Toxic GHS08: Health hazard GHS09: Environmental hazard
GHS Signal word Danger
H301, H331, H373, H410
P260, P261, P264, P270, P271, P273, P301+310, P304+340, P311, P314, P321, P330, P391, P403+233, P405, P501
Related compounds
Other anions
Sodium oxide
Sodium sulfide
Sodium telluride
Sodium polonide
Other cations
Hydrogen selenide
Lithium selenide
Potassium selenide
Rubidium selenide
Caesium selenide
Related compounds
Sodium selenite
Sodium selenate
Aluminum selenide
Antimony selenide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Sodium selenide is an inorganic compound of sodium and selenium with the chemical formula Na2Se.

Preparation

This colourless solid is prepared by the reaction of selenium with a solution of sodium in liquid ammonia at −40 °C.[3] Alternatively, sodium selenide can be prepared by the reaction of gaseous hydrogen selenide with metallic sodium at 100 °C.

Reactions

Like other alkali metal chalcogenides, this material is highly sensitive to water, easily undergoing hydrolysis to give mixtures of sodium biselenide (NaSeH) and hydroxide. This hydrolysis occurs because of the extreme basicity of the Se2− ion.

Na2Se + H2O → NaHSe + NaOH

Similarly, sodium selenide is readily oxidized to polyselenides, a conversion signaled by off-white samples.

Sodium selenide reacts with acids to produce toxic hydrogen selenide gas.

Na2Se + 2 HCl → H2Se + 2 NaCl

The compound reacts with electrophiles to produce the selenium compounds. With alkyl halides, one obtains a variety of organoselenium compounds:

Na2Se + 2 RBr → R2Se + 2 NaBr

Organotin and organosilicon halides react similarly to give the expected derivatives:

Na2Se + 2 Me3XCl → (Me3X)2Se + 2 NaCl (X ∈ Si, Ge, Sn)

References

  1. Cite error: Invalid <ref> tag; no text was provided for refs named crc
  2. Bonneau, Philippe R.; Jarvis, Robert F.; Kaner, Richard B. (1992). "Solid-state metathesis as a quick route to transition-metal mixed dichalcogenides". Inorganic Chemistry 31 (11): 2127–2132. doi:10.1021/ic00037a027. 
  3. Brauer, G. ed. (1963) Handbook of Preparative Inorganic Chemistry, 2nd Ed., Academic Press, NY., Vol. 1. p. 421.