Preparation of potassium hexafluoromanganate(IV)
Plastic beakers and stirring rods are required for this preparation. Eighty-nine grams of 48% hydrofluoric acid are mixed with 11ml of water in a 150ml plastic beaker and 8.9g of anhydrous potassium carbonate are added in portions with stirring. When the effervescence has subsided, the solution of potassium hydrogen fluoride (KHF2), is cooled thoroughly in an ice bath and 8g of powdered potassium permanganate are stirred in. Without delay, absolute ether (free from al cohol and peroxides), is added dropwise, with good stirring, from a medicine dropper or a small burette. To avoid any possible reaction with the non-vitreous material, the ether should be run into the center of the solution and not onto the walls of the plastic vessel. About 2ml of ether are required for the complete discharge of the characteristic purple color of the potassium permanaganate. A brown liquid and yellow crystals of product remain at the end of the reaction; the mixture is left for 20 minutes in the ice bath and then the clear liquid is decanted into a second plastic beaker as completely as possible in order to avoid etching the filter flask subsequently. The brown mother liquor is reserved for the isolation of K3[MnF6]. The crystals of product are transferred to the suction filter with about 25-30 ml of glacial acetic acid, pressed dry, washed twice more with 20ml portions of acid, and finally with a similar quantity of acetone. The complex fluoride is dried in vacuo on filter paper. Yield = 7.5-8.0g. The product must be stored out of contact with moist air in plastic or paraffin coated vials because water causes instant hydrolysis to MnO2, and the fluoride, itself, etches glass with the formation of a brown deposit.
Inorganic laboratory preparations, by G. G. Schlessinger, 88-89, 1962
UNII-6Z77FB1PML, 6Z77FB1PML, Dipotassium hexafluoromanganate, Potassium hexafluoromanganate(IV), Dipotassium hexafluoromanganate(2-), Manganese potassium fluoride (K2MnF6), Potassium hexafluoromanganate(IV) [MI], Manganate(2-), hexafluoro-, potassium (1:2), (oc-6-11)-, 16962-31-5