Sodium hypobromite

Sodium hypobromite

Names
IUPAC name Sodium hypobromite
Identifiers
CAS Number	13824-96-9  Y
3D model (JSmol)	Interactive image
ChemSpider	146053
ECHA InfoCard	100.034.096
EC Number	237-520-4
PubChem CID	23673712
UNII	ZU61C4V8RA  Y
CompTox Dashboard (EPA)	DTXSID40930039
InChI InChI=1S/BrO.Na/c1-2;/q-1;+1 Key: CRWJEUDFKNYSBX-UHFFFAOYSA-N
SMILES [O-]Br.[Na+]
Properties
Chemical formula	NaOBr
Molar mass	118.893 g·mol−1
Appearance	orange solid
Related compounds
Other anions	Sodium bromide Sodium bromite Sodium bromate Sodium perbromate
Related compounds	Hypobromous acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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 NaOBr·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).

Sodium hypobromite slowly disproportionates to sodium bromide and sodium bromate:

3 NaOBr → 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.
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.