CsH2PO4

CsH2PO4, or cesium dihydrogen phosphate, is an inorganic salt composed of cesium ions (Cs+) and dihydrogen phosphate anions (H2PO4−). It is the cesium analogue of dihydrogen phosphate and is typically prepared by reacting a cesium salt (such as Cs2CO3 or CsCl) with phosphoric acid and then crystallizing the Cesium dihydrogen phosphate.

In aqueous solution, CsH2PO4 is highly soluble, and the solid forms crystalline material that is used in various laboratory and industrial contexts. The salt serves as a source of Cs+ in chemical synthesis and can function as a buffering component because the dihydrogen phosphate system participates in phosphate buffer equilibria. Because dihydrogen phosphate species are involved in proton transfer reactions, CsH2PO4 has attracted research attention as a potential solid-state proton conductor at elevated temperatures, with interest in electrochemical and energy applications.

Applications and handling: CsH2PO4 is used as a source of cesium ions in synthesis and, in research settings, as a component in buffer systems and in studies of proton-conducting materials. It is typically handled as a dry, standardized inorganic salt and, like other phosphate salts, should be managed with appropriate laboratory safety practices. It is not considered highly toxic but can irritate skin, eyes, and the respiratory tract if dust is inhaled or if there is prolonged exposure.

See also: KH2PO4, NaH2PO4, dihydrogen phosphate salts.