Strontium Carbonyl, Sr(CO)₂

When a solution of strontium ammonium in ammonia is treated with carbon monoxide at -45° C., a dull yellow, powdery mass of Strontium Carbonyl, Sr(CO)₂, is obtained. It becomes bright yellow on exposure to moist air, forms a clear yellow solution with water, and blackens when heated under reduced pressure yielding a mixture of carbon with strontium oxide and carbonate.