Bromine dioxide
IUPAC name
Bromine dioxide
3D model (JSmol)
  • InChI=1S/BrO2/c2-1-3 ☒N
  • InChI=1/BrO2/c2-1-3
  • O=Br=O
Molar mass 111.903 g/mol[1]
Appearance unstable yellow crystals
Melting point decomposes around 0°C


Related compounds
Other anions
Bromine monoxide
Bromine trifluoride
Bromine pentafluoride
Other cations
Oxygen difluoride
Dichlorine monoxide
Chlorine dioxide
Iodine dioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Bromine dioxide is the chemical compound composed of bromine and oxygen with the formula BrO2. It forms unstable yellow[2] to yellow-orange[1] crystals. It was first isolated by R. Schwarz and M. Schmeißer in 1937 and is hypothesized to be important in the atmospheric reaction of bromine with ozone.[3] It is similar to chlorine dioxide, the dioxide of its halogen neighbor one period higher on the periodic table.[citation needed]


Bromine dioxide is formed when an electric current is passed through a mixture of bromine and oxygen gases at low temperature and pressure.[4]

Bromine dioxide can also be formed by the treatment of bromine gas with ozone in trichlorofluoromethane at −50 °C.[1]

When mixed with a base, bromine dioxide gives the bromide and bromate anions:[4]

6 BrO2 + 6 NaOHNaBr + 5 NaBrO3 + 3 H2O


  1. ^ a b c Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, p. 74, ISBN 0-8493-8671-3, retrieved 17 March 2009
  2. ^ a b Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, p. 447, ISBN 0-8493-0594-2
  3. ^ Müller, Holger S. P.; Miller, Charles E.; Cohen, Edward A. (1997). "The rotational spectrum and molecular properties of bromine dioxide, OBrO". The Journal of Chemical Physics. 107 (20): 8292. Bibcode:1997JChPh.107.8292M. doi:10.1063/1.475030. ISSN 0021-9606.
  4. ^ a b Arora, M.G. (1997), P-Block Elements, New Delhi: Anmol Publications, p. 256, ISBN 978-81-7488-563-0, retrieved 17 March 2009