Barium Ruthenocyanide, Ba₂Ru(CN)₆

Barium Ruthenocyanide, Ba₂Ru(CN)₆.6H₂O, may be prepared from the potassium salt as pale, straw-coloured monoclinic crystals. It is slightly soluble in cold water. When preserved over sulphuric acid the crystals lose water of crystallisation; at 100° C. 5.5 molecules are expelled, the remaining half molecule being retained up to nearly 200° C.