Barium manganate

Chemical properties

blue to dark blue-black fine crystalline powder

The Uses of Barium manganate

As pigment in fresco painting instead of Scheele's green because not so poisonous as latter. As mild oxidizing agent in organic synthesis.

The Uses of Barium manganate

Useful for the selective oxidation of diols.

Purification Methods

Wash the salt with conductivity H2O by decantation until the supernatant gives a faint test for Ba2+ . Remove excess H2O in a vacuum (IMPORTANT), then heat at 100o and the last traces of H2O are removed in a vacuum desiccator over P2O5. Store it over KOH. It disproportionates in hot H2O or dilute acid into Ba(MnO2)2 and MnO2, and is a mild oxidant. [Schlezinger & Siems J Am Chem Soc 46 1965 1924, Nyholm & Woolliams Inorg Synth XI 56 1968.]