BrO4

BrO4 most commonly denotes the perbromate anion, BrO4−, the conjugate base of perbromic acid (HBrO4). In inorganic chemistry it represents an oxoanion of bromine in the +7 oxidation state, analogous to the perchlorate (ClO4−) and periodate (IO4−) families.

The structure of BrO4− is tetrahedral, with four equivalent Br–O bonds surrounding the central bromine atom. In salts, BrO4− pairs with various cations such as Na+, K+, or Cs+. The tetrahedral geometry and high oxidation state give the ion a strong tendency to act as an oxidizing agent.

Perbromates are prepared by oxidation of bromate-bearing solutions under strongly oxidizing conditions, and they are isolable as solid salts such as sodium perbromate (NaBrO4) and potassium perbromate (KBrO4). They are generally stable as solids but can decompose on heating, releasing oxygen gas and/or forming lower bromine oxoanions.

In solution, BrO4− can participate in redox reactions, typically under acidic or basic conditions, and is mainly encountered in research and specialized analytical contexts. Compared to the more common perchlorates, perbromates are less widely used, owing to their relative rarity, preparation challenges, and cost.

Safety notes are important: perbromates are strong oxidizers and can react vigorously with reducing agents or organic materials. They should be handled with appropriate precautions, stored away from heat and incompatible substances, and used within the confines of established laboratory guidelines.

Note: In some contexts, BrO4 may be used informally to refer to the perbromate ion BrO4−; the neutral molecule BrO4 is not a standard or widely isolated species.