Preparation of potassium hexacyanomanganate(III)
Thirty-nine grams of manganese(III) phosphate monohydrate are added in 5g portions with stirring to a solution of 150g of potassium cyanide in 400ml of water at 75°C. The latter solution is prepared by stirring the cyanide into the water previously heated to 95°C. The strong endothermic heat of solution reduces the temperature to about 75°C. As the phosphate is added to the cyanide the heat of the reaction maintains the temperature between 75-80°C. A deep red liquid forms and a fresh portion of phosphate is added only when the previous one has completely dissolved. At no time should the temperature exceed 80 °C ; otherwise manganese (III) oxide is precipitated, causing a loss in yield. The solution is filtered by suction while hot, if necessary, using one gram of Celite as a filter aid, and then allowed to stand under a hood in a large open evaporating dish. The brick-red product that forms is filtered off daily over a period of about one week. Any crystalline crusts which form on the surface of the liquid are broken up to facilitate evaporation. When the volume of the mother liquor has reached 300ml and the color has become a very pale orange, the isolation of product is complete. Dry in vacuo. Total Yield = 70g or 92% based on manganese (III) phosphate.
Inorganic laboratory preparations, by G. G. Schlessinger, 86-88, 1962
Potassium manganocyanide, Tripotassium hexacyanomanganate(3-), EINECS 237-848-8, Tripotassium hexakis(cyano-C)manganate, MANGANATE(3-), HEXACYANO-, TRIPOTASSIUM, Manganate(3-), hexakis(cyano-C)-, tripotassium, (OC-6-11)-, Potassium cyanomanganate(III) (6CI), Potassium hexacyanomanganate(III) (7CI), LS-89190
Potassium cyanomanganate(III), Potassium hexacyanomanganate(III), CID26400, 14023-90-6