Cesium carbonate is an inorganic compound, white solid at normal temperature and pressure, easily soluble in water, placed in the air quickly hygroscopic. Cesium carbonate solution is strongly alkaline, can react with acid, produce the corresponding cesium salt and water, and release carbon dioxide. Cesium carbonate should be sealed, dried and stored separately from acids.

Caesium carbonate (Cs2CO3 molecular weight 325.82) CAS carbonate no. 534-17-8

Many properties of cesium carbonate in organic synthesis come from the soft lewis acid of cesium ion, which makes it soluble in organic solvents such as alcohol, DMF and ether. Better solubility in organic solvents enables cesium carbonate to participate in palladium catalyzed chemical reactions such as Heck, Suzuki and Sonogashira reactions as an effective inorganic base.