View source for Perbromate

{{chembox
| OtherNames = Tetraoxidobromate(1−)
| Section1 = {{Chembox Identifiers
|   ChemSpiderID = 4574125
|   InChI=1/BrHO4/c2-1(3,4)5/h(H,2,3,4,5)/p-1
|   InChIKey = LLYCMZGLHLKPPU-REWHXWOFAT
|   StdInChI=1S/BrHO4/c2-1(3,4)5/h(H,2,3,4,5)/p-1
|   StdInChIKey = LLYCMZGLHLKPPU-UHFFFAOYSA-M
|   CASNo = 16474-32-1
  }}
| Section3 = {{Chembox Structure
|   Reference = <ref>{{citation | first1 = William | last1 = Levason | first2 = J. Steven | last2 = Ogden | first3 = Mark D. | last3 = Spicer | first4 = Nigel A. | last4 = Young | title = Characterisation of the oxo-anions of bromine BrO<sub>''x''</sub><sup>−</sup> (''x''&nbsp;= 1–4) by infrared, Raman, nuclear magnetic resonance, and bromine ''K''-edge extended X-ray absorption fine structure techniques | journal = J. Chem. Soc., Dalton Trans. | year = 1990 | issue = 1 | pages = 349–53 | doi = 10.1039/DT9900000349}}.</ref>
|   MolShape = ''r''(Br–O) = 161 pm
  }}
| Section8 = {{Chembox Related
|   OtherAnions = [[Perchlorate]]<br/>[[Periodate]]
  }}
}}
A '''perbromate''' is a [[salt]] or [[ester]] of [[perbromic acid]]. Perbromates, including perbromic acid,<ref group=note>[[Perbromic acid]] is fully dissociated in solution. By analogy with [[perchloric acid]], the solid HBrO<sub>4</sub>·2H<sub>2</sub>O is expected to contain [(H<sub>2</sub>O)<sub>2</sub>H]<sup>+</sup>[BrO<sub>4</sub>]<sup>−</sup>.</ref> are the only well-characterized compounds of bromine in the +7 [[oxidation state]].

Perbromates are thermodynamically more oxidizing than [[perchlorate]]s or [[periodate]]s, and eluded preparation for more than 100&nbsp;years until 1968.<ref name="1st">{{citation | title = The Synthesis of Perbromates | first = Evan H. | last = Appelman | journal = J. Am. Chem. Soc. | year = 1968 | volume = 90 | issue = 7 | pages = 1900–1 | doi = 10.1021/ja01009a040}}. {{citation | first = Evan H. | last = Appelman | title = Perbromic acid and perbromates: synthesis and some properties | journal = Inorg. Chem. | volume = 8 | issue = 2 | pages = 223–27 | year = 1969 | doi = 10.1021/ic50072a008}}.</ref><ref name="G&E">{{Greenwood&Earnshaw1st|pages=1020–22}}.</ref><ref name="C&W">{{Cotton&Wilkinson5th|pages=568–69}}.</ref> However, they are kinetically quite inert, especially in dilute solution.<ref name="G&E"/><ref name="C&W"/><ref>{{citation | title = Electron-transfer reactions between the perbromate ion and iron(II) complexes of 2,2'-bipyridine and substituted 1,10-phenanthrolines | first1 = A. M. | last1 = Kjaer | first2 = J. | last2 = Ulstrup | journal = Inorg. Chem. | year = 1982 | volume = 21 | issue = 9 | pages = 3490–94 | doi = 10.1021/ic00139a044}}.</ref>

==History==
Although [[perchlorate]]s and [[periodate]]s have been known since the early nineteenth century, perbromates proved far more elusive. The first claim of preparation came in 1863,<ref>{{citation | first = Hermann | last = Kämmerer | title = Notizen | journal = J. Prakt. Chem. | year = 1863 | volume = 90 | pages = 190 | doi = 10.1002/prac.18630900126}}. {{citation | first = Hermann | last = Kaemmerer | title = Studien über die Sauerstoffverbindungen der Halogene | journal = Ann. Phys. (Berlin) | volume = 214 | issue = 11 | pages = 390–417 | year = 1869 | doi = 10.1002/andp.18692141104}}.</ref> but proved unrepeatable.<ref>{{citation | first = M. M. | last = Pattison Muir | title = Note on the perbromates | journal = J. Chem. Soc. | year = 1876 | volume = 30 | page = 469 | doi = 10.1039/JS8763000469}}.</ref><ref>{{citation | first = Guido | last = Wolfram | title = Ueber die Darstellung der Perbromsäure | journal = Justus Liebigs Ann. Chem. | year = 1879 | volume = 198 | issue = 1–2 | pages = 95–98 | doi = 10.1002/jlac.18791980107}}.</ref> Several later attempts to prepare perbromates were equally unsuccessful.<ref>{{citation | first = Ernest H. | last = Cook | title = Effect of heat on iodates and bromates. I. Potassic iodate and bromate | journal = J. Chem. Soc., Trans. | year = 1894 | volume = 65 | pages = 802–14 | doi = 10.1039/CT8946500802}}.</ref><ref>{{citation | first1 = G. M. | last1 = Bancroft | first2 = H. D. | last2 = Gesser | title = The search for perbromate—I: The thermal decomposition of bromates | journal = J. Inorg. Nucl. Chem. | year = 1965 | volume = 27 | issue = 7 | pages = 1545–56 | doi = 10.1016/0022-1902(65)80016-1}}.</ref> Several authors surmised that perbromates were fundamentally unstable.<ref>{{citation | first = Z. Z., Jr. | last = Hugus | title = The Possible Use of 4f Orbitals in Bonding: the Enhanced Stability of the Higher Oxidation States of Iodine, Tellurium and Antimony; the Non-existence of Perbromic Acid | journal = J. Am. Chem. Soc. | year = 1952 | volume = 74 | issue = 4 | pages = 1076–77 | doi = 10.1021/ja01124a502}}.</ref><ref>{{citation | first = D. S. | last = Urch | title = The perbromate problem | journal = J. Inorg. Nucl. Chem. | year = 1963 | volume = 25 | issue = 7 | pages = 771–78 | doi = 10.1016/0022-1902(63)80360-7}}.</ref>

The first clear evidence of the existence of the perbromate anion came from "hot-atom" techniques. A sample of the β<sup>−</sup>-emittor [[selenium-83]] (''t''<sub>½</sub>&nbsp;= 25&nbsp;min) was prepared in the form of the [[selenate]] anion SeO{{su|b=4|p=−}} and allowed to decay into [[bromine-83]]. Approximately 14% of the <sup>83</sup>Br activity (β<sup>−</sup>, ''t''<sub>½</sub>&nbsp;= 2.4&nbsp;h) coprecipitated with [[rubidium perchlorate]], as expected for a perbromate species.<ref name="1st"/>

Electrolysis of [[lithium bromate]] at a [[platinum]] [[anode]] gave a yield of about 2% perbromate.<ref name="1st"/> Small amounts of perbromate (1–4% yield) were also formed by the [[xenon difluoride]] oxidation of bromates, while [[perxenate]], [[peroxodisulfate]] and [[ozone]] were ineffective as oxidizing agents.<ref name="1st"/>

==Notes and references==
===Notes===
{{reflist|group=note}}

===References===
{{reflist|2}}

===Further reading===
*{{citation | first1 = Gerald K. | last1 = Johnson | first2 = Peter N. | last2 = Smith | first3 = Evan H. | last3 = Appelman | first4 = Ward N. | last4 = Hubbard | title = Thermodynamic properties of the perbromate and bromate ions | journal = Inorg. Chem. | volume = 9 | issue = 1 | pages = 119–25 | year = 1970 | doi = 10.1021/ic50083a025}}.
*{{citation | first1 = Ulrik K. | last1 = Klaening | first2 = Kjeld J. | last2 = Olsen | first3 = Evan H. | last3 = Appelman | title = Photolysis of perbromate in aqueous solution | journal = J. Chem. Soc., Faraday Trans. 1 | volume = 71 | pages = 473–84 | year = 1975 | doi = 10.1039/F19757100473}}.
*{{citation | first1 = K. J. | last1 = Olsen | first2 = K. | last2 = Sehested | first3 = E. H. | last3 = Appelman | title = Pulse-radiolysis of aqueous KBrO<sub>4</sub> solutions | journal = Chem. Phys. Lett. | volume = 19 | issue = 2 | pages = 213–14 | year = 1973 | doi = 10.1016/0009-2614(73)85057-2}}.
*{{citation | title = Preparation of an alkyl perbromate | first1 = Kurt | last1 = Baum | first2 = Charles D. | last2 = Beard | first3 = Vytautas | last3 = Grakauskas | journal = J. Am. Chem. Soc. | year = 1975 | volume = 97 | issue = 2 | pages = 267–68 | doi = 10.1021/ja00835a005}}. {{citation | inventor1-last = Baum | inventor1-first = Kurt | inventor2-last = Beard | inventor2-first = Charles D. | inventor3-last = Grakaukas | inventor3-first = Vitautas | assignee = U.S. Dept. of the Navy | title = Preparation of alkyl perbromates | country-code = US | patent-number = 4022811 | publication-date = 1977-10-05}}.
*{{citation | title = Nonexistent compounds. Two case histories | first = Evan H. | last = Appelman | journal = Acc. Chem. Res. | year = 1973 | volume = 6 | issue = 4 | pages = 113–17 | doi = 10.1021/ar50064a001}}.
*{{citation | title = Heat capacity of potassium perbromate, KBrO<sub>4</sub>, between 5 and 350°K | first1 = Felix | last1 = Schreiner | first2 = Darrell W. | last2 = Osborne | first3 = Alphonsus V. | last3 = Pocius | first4 = Evan H. | last4 = Appelman | journal = Inorg. Chem. | year = 1970 | volume = 9 | issue = 10 | pages = 2320–24 | doi = 10.1021/ic50092a024}}.
*{{citation | first = E. H. | last = Appelman | title = Perbromic acid and potassium perbromate | journal = Inorg. Synth. | year = 1972 | volume = 13 | pages = 1–9 | doi = 10.1002/9780470132449.ch1}}.

==External links==
{{wikipedia|Perbromate}}

[[Category:Perbromates| ]]
[[Category:Bromine oxoanions]]

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