Topic summary
Perrhenate
The perrhenate ion is the anion with the formula ReO
4, or a compound containing this ion. The perrhenate anion is tetrahedral, being similar in size and shape to perchlorate and the valence isoelectronicpermanganate. The perrhenate anion is stable over a broad pH range and can be precipitated from solutions with the use of organic cations. At normal pH, perrhenate exists as metaperrhenate (ReO
4), but at high pH mesoperrhenate (ReO
5) forms. Perrhenate, like its conjugate acid perrhenic acid, features rhenium in the oxidation state of +7 with a d configuration. Solid perrhenate salts takes on the color of the cation.