Space-filling model of the perbromate anion, BrO−
4 | |
Identifiers | |
---|---|
3D model (
JSmol)
|
|
ChEBI | |
ChemSpider | |
PubChem
CID
|
|
| |
| |
Properties | |
BrO4− | |
Molar mass | 143.901 g·mol−1 |
Related compounds | |
Related compounds
|
bromide hypobromite bromite bromate |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
In
chemistry, the perbromate ion is the
anion having the chemical formula BrO−
4. It is an
oxyanion of
bromine, the
conjugate base of
perbromic acid, in which bromine has the
oxidation state +7.
[1] Unlike its chlorine (
ClO−4) and iodine (
IO−4)
analogs, it is difficult to synthesize.
[2] It has
tetrahedral molecular geometry.
[3]
The term perbromate also refers to a compound that contains the BrO−
4 anion or the –OBrO
3
functional group.
The perbromate ion is a strong oxidizing agent.
[2] The reduction potential for the BrO−
4/
Br− couple is +0.68 V at pH 14. This is comparable to
selenite's reduction potential.
Attempted syntheses of perbromates were unsuccessful until 1968, when it was finally obtained by the beta decay of selenium-83 in a selenate salt: [4] [5]
Subsequently, it was successfully synthesized again by the
electrolysis of LiBrO
3, although only in low yield.
[5]
[6] Later, it was obtained by the oxidation of
bromate with
xenon difluoride.
[3]
[7] Once perbromates are obtained,
perbromic acid can be produced by protonating BrO−
4.
[2]
One effective method of producing perbromate is by the oxidation of bromate with fluorine under alkaline conditions: [2] [8]
This synthesis is much easier to perform on a large scale than the electrolysis route or oxidation by xenon difluoride. [8]
In 2011 a new, more effective synthesis was discovered: perbromate ions were formed through the reaction of hypobromite and bromate ions in an alkaline sodium hypobromite solution. The reaction (and its perchlorate analogue) occurs naturally, but very slowly, requiring several days to complete. [9]
Diperiodatonickelate anions in alkaline solution can oxidise bromate to perbromate. This is a relatively lower cost and fluorine free synthesis. [10]
Other bromine anions:
Bromine oxidation state | −1 | +1 | +3 | +5 | +7 |
---|---|---|---|---|---|
Name | bromide | hypobromite | bromite | bromate | perbromate |
Formula | Br− | BrO− | BrO− 2 |
BrO− 3 |
BrO− 4 |
Structure |
Space-filling model of the perbromate anion, BrO−
4 | |
Identifiers | |
---|---|
3D model (
JSmol)
|
|
ChEBI | |
ChemSpider | |
PubChem
CID
|
|
| |
| |
Properties | |
BrO4− | |
Molar mass | 143.901 g·mol−1 |
Related compounds | |
Related compounds
|
bromide hypobromite bromite bromate |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
In
chemistry, the perbromate ion is the
anion having the chemical formula BrO−
4. It is an
oxyanion of
bromine, the
conjugate base of
perbromic acid, in which bromine has the
oxidation state +7.
[1] Unlike its chlorine (
ClO−4) and iodine (
IO−4)
analogs, it is difficult to synthesize.
[2] It has
tetrahedral molecular geometry.
[3]
The term perbromate also refers to a compound that contains the BrO−
4 anion or the –OBrO
3
functional group.
The perbromate ion is a strong oxidizing agent.
[2] The reduction potential for the BrO−
4/
Br− couple is +0.68 V at pH 14. This is comparable to
selenite's reduction potential.
Attempted syntheses of perbromates were unsuccessful until 1968, when it was finally obtained by the beta decay of selenium-83 in a selenate salt: [4] [5]
Subsequently, it was successfully synthesized again by the
electrolysis of LiBrO
3, although only in low yield.
[5]
[6] Later, it was obtained by the oxidation of
bromate with
xenon difluoride.
[3]
[7] Once perbromates are obtained,
perbromic acid can be produced by protonating BrO−
4.
[2]
One effective method of producing perbromate is by the oxidation of bromate with fluorine under alkaline conditions: [2] [8]
This synthesis is much easier to perform on a large scale than the electrolysis route or oxidation by xenon difluoride. [8]
In 2011 a new, more effective synthesis was discovered: perbromate ions were formed through the reaction of hypobromite and bromate ions in an alkaline sodium hypobromite solution. The reaction (and its perchlorate analogue) occurs naturally, but very slowly, requiring several days to complete. [9]
Diperiodatonickelate anions in alkaline solution can oxidise bromate to perbromate. This is a relatively lower cost and fluorine free synthesis. [10]
Other bromine anions:
Bromine oxidation state | −1 | +1 | +3 | +5 | +7 |
---|---|---|---|---|---|
Name | bromide | hypobromite | bromite | bromate | perbromate |
Formula | Br− | BrO− | BrO− 2 |
BrO− 3 |
BrO− 4 |
Structure |