Perbromate

Structure of perbromic acid.

As Perbromates refers to the salts of perbromic with the molecular formula BrO ₄ ^- . The central bromine atom is in the +7 oxidation state and is tetrahedrally surrounded by four oxygen atoms.

History and manufacture

Despite numerous attempts at synthesis, it was not possible to find a synthetic route for macroscopic amounts of perbromate until late. As recently as 1963, calculations showed that perbromates cannot be stable in principle and that synthesis attempts are therefore pointless. The first synthesis then used the radioactive decay of selenate with radioactive ⁸³ Se:

${\displaystyle \mathrm {^{83}SeO_{4}^{2-}\longrightarrow \ ^{83}BrO_{4}^{-}+\beta ^{-}} }$

The electrolytic oxidation of bromate to perbromate was also described there, but only with a yield of 2%. Then later the oxidation of bromate with elemental fluorine succeeded . Despite experimental difficulties in working with fluorine gas, this has so far been the best method of synthesizing perbromate. In the meantime, however, it has been possible to synthesize perbromate from bromide solution by means of electrolysis on doped diamond anodes. However, the product is present alongside the bromate. The yields are in the lower percentage range.

properties

Similar to the homologous perchlorate ion , the perbromate ion is a weakly coordinating, mesomerically stabilized anion and an oxidizing agent . In contrast to perchlorates, however, perbromates do not decompose thermally to bromides , but rather react to bromates by releasing oxygen .

${\displaystyle \mathrm {2\ KBrO_{4}\longrightarrow \ 2\ KBrO_{3}\ +O_{2}} }$

Potassium perbromate decomposes to potassium bromate and oxygen when heated

In most cases, the more accessible perchlorate salts are used instead of perbromate salts.

See also

• Bromides : Br ^-
• Hypobromites : BrO ^-
• Bromites : BrO ₂ ^-
• Bromates : BrO ₃ ^-

Individual evidence

1. ↑ DS Urch: The perbromate problem , in: J. Inorg. Nucl. Chem. 1963 , 25 , 771-777.
2. ^ EH Appelman: Synthesis of perbromates , in: J. Am. Chem. Soc. 1968 , 90 , 1900-1901, doi : 10.1021 / ja01009a040 .
3. ^ S. Siegel, B. Tani, E. Appelman Crystal structure of potassium perbromate , in: Inorg. Chem. 1969 , 8 , 1190-1191; doi : 10.1021 / ic50075a036
4. ↑ H. Bergmann, J. Rollin, T. Iourtchouk, DE Patent 10 2009 040 651.4, 2009 .
5. ↑ Henry Bergmann, Tatiana Iourtchouk, Johanna Rollin: Perbromates - a new synthesis and detection ability , LABO June 2010 , 8-10.