Question

The colour of KMnO₄ is due to ______.

Options

• M → L charge transfer transition

• d-d trannsition

• L → M charge transfer transition

• σ-σ* transition

Answer 1

The colour of KMnO₄ is due to L → M charge transfer transition.

Explanation:

In KMnO₄ (potassium permanganate), the Mn atom is in the +7 oxidation state, which has no d-electrons. So, d-d transition is not possible. The purple/violet colour of KMnO₄ is due to the movement of an electron from a ligand (L) (like oxygen) to the metal (Mn). This is called Ligand to Metal Charge Transfer (LMCT).