Hydrogen selenide

  • Formula: H2Se
  • Hill system formula: H2Se1
  • CAS registry number: [7783-07-5]
  • Formula weight: 80.976
  • Class: selenide
  • Colour: colourless
  • Appearance: gas
  • Melting point: -66°C
  • Boiling point: -42°C
  • Density: 2120 kg m-3

The following are some synonyms of hydrogen selenide:

  • hydrogen selenide
  • hydrogen(I) selenide
  • dihydrogen monoselenide
  • dihydrogen selenide

The oxidation number of hydrogen in hydrogen selenide is 1.


Hydrogen selenide (danger!!) can be made in the laboratory by the direct reaction of the elements but might best be made from aluminium selenide. With considerable care, the reaction between aluminium selenide and water can be used in the laboratory to make hydrogen(II) selenide. Hydrogen(II) selenide is a colourless gas which boils at -42°C and freezes at -66°C.

Al2Se3 + (3 + x)H2O → 3H2Se + Al2O3.xH2O

Solid state structure

  • Geometry of hydrogen: 1 coordinate: terminus
  • Prototypical structure:

Crystal structure of hydrogen selenide

Element analysis

The table shows element percentages for H2Se (hydrogen selenide).

Element %
H 2.49
Se 97.51

Isotope pattern for H2Se

The chart below shows the calculated isotope pattern for the formula H2Se with the most intense ion set to 100%.


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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