Sodium hypobromite

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Sodium hypobromite
NaOBr.svg
Names
IUPAC name
Sodium hypobromite
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.034.096 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 237-520-4
PubChem CID
UNII
  • InChI=1S/BrO.Na/c1-2;/q-1;+1
    Key: CRWJEUDFKNYSBX-UHFFFAOYSA-N
  • [O-]Br.[Na+]
Properties
NaOBr
Molar mass 118.893 g·mol−1
Appearanceorange solid
Related compounds
Other anions
Related compounds
Hypobromous acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Sodium hypobromite is an inorganic compound with the chemical formula Na O Br . It is a sodium salt of hypobromous acid. It consists of sodium cations Na+ and hypobromite anions OBr. It is usually obtained as the pentahydrate, so the compound that is usually called sodium hypobromite actually has the formula NaBrO·5H2O. It is a yellow-orange solid that is soluble in water. It adopts a monoclinic crystal structure with a Br–O bond length of 1.820 Å. [1] It is the bromine analogue of sodium hypochlorite, the active ingredient in common bleach. In practice the salt is usually encountered as an aqueous solution.

Sodium hypobromite arises by treatment of aqueous solution of bromine with base: [2]

Br2 + 2 NaOH → NaBr + NaOBr + H2O

It can be prepared in situ for use as a reagent, such as in the synthesis of 3-aminopyridine from nicotinamide [3] (Hofmann rearrangement).

Synthesis of 3-Aminopyridine.gif

Sodium hypobromite slowly disproportionates to sodium bromide and sodium bromate:

3 NaBrO → 2 NaBr + NaBrO3

References

  1. Topić, Filip; Marrett, Joseph M.; Borchers, Tristan H.; Titi, Hatem M.; Barrett, Christopher J.; Friščić, Tomislav (2021). "After 200 Years: The Structure of Bleach and Characterization of Hypohalite Ions by Single-Crystal X-Ray Diffraction". Angew. Chem. Int. Ed. 60 (46): 24400–24405. doi:10.1002/anie.202108843. PMID   34293249. S2CID   236199263.
  2. Schmeisser, M. (1963). "Sodium Hypobromite". In Brauer, Georg (ed.). Handbook of Preparative Inorganic Chemistry. Vol. 1 (2nd ed.). New York: Academic Press. pp. 310–311. ISBN   9780323161275.{{cite book}}: ISBN / Date incompatibility (help)
  3. Allen, C. F. H.; Wolf, Calvin N. (1950). "3-Aminopyridine". Organic Syntheses . 30: 3. doi:10.15227/orgsyn.030.0003 ; Collected Volumes, vol. 4, p. 45.