KMnO4 or Potassium Permanganate is a salt formed of K+ and MnO4- ions. It dissolves in water to give intensely pink or purple solutions, the evaporation of which leaves prismatic purplish-black glistening crystals.
KMnO4 in Organic Chemistry
- Dilute solutions of KMnO4 convert alkenes into diols ( Have 2 -OH groups). This behaviour is used as a test for double or triple bonds in organic compounds, since the reaction decolorizes the purple KMnO4 and generates a brown MnO2 percipitate.
- KMnO4 is a strong oxidising agent and can react with a variety of groups.
- Under acidic conditions, the alkene double bond is cleaved to give the appropriate carboxylic acid (-COOH )
- Potassium permanganate oxidises aldehydes to carboxylic acids (From -COH to -COOH)
- Primary alcohols are directly oxidised to carboxylic acids.
- Oxidises the Alkyl group in Toluene (1-MethylBenzene) to a carboxyl group (-COOH)