Chlorine compounds: dichlorine heptoxide

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The chlorine in dichlorine heptoxide formally is in the oxidation state 7.

Dichlorine heptoxide

  • Formula as often written: Cl2O7
  • Hill system formula: Cl2O7
  • CAS registry number: [10294-48-1]
  • Formula weight: 182.901
  • Class: oxide


  • dichlorine heptoxide
  • chlorine(VII) oxide
  • chlorine oxide
  • perchloric anhydride

Physical properties

  • Colour: colourless
  • Appearance: liquid
  • Melting point: -91.5°C
  • Boiling point: 83°C
  • Density: l900 kg m-3


Coming soon...

Element analysis

Element percentages for the elements in dichlorine heptoxide
Element %
Cl 38.77
O 61.23


Not available

Isotope pattern

What follows is the calculated isotope pattern for the Cl2O7 unit with the most intense ion set to 100%.

Formula: Cl2O7

mass  %
182 100.0 __________________________________________________
183 0.3
184 65.4 _________________________________
185 0.2
186 11.1 ______
187 0.0
188 0.2


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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