BeCl2

BeCl2, or beryllium chloride, is an inorganic compound with the formula BeCl2. It appears as a colorless, crystalline solid at room temperature and is highly reactive toward moisture. In the gas phase it exists mainly as a linear BeCl2 molecule, whereas in the solid state it adopts a polymeric structure in which Be centers are four-coordinate, linked by bridging chloride ligands.

BeCl2 is prepared by direct combination of beryllium with chlorine at elevated temperature, or by chlorination of beryllium oxide: BeO + 2 HCl → BeCl2 + H2O. It readily forms Lewis acid–base adducts with donor solvents. In non-coordinating media it tends to polymerize; in donor solvents such as ethers or THF it forms adducts like BeCl2(ether)2 or BeCl2(THF)2.

Physically, BeCl2 is highly hygroscopic and hydrolyzes in water to give Be(OH)2 and HCl; upon continued hydrolysis Be(OH)2 can dehydrate to BeO. In aqueous solution the beryllium centers are heavily hydrated and the solutions are strongly acidic.

BeCl2 finds use as a precursor to organoberyllium compounds and as a laboratory starting material for preparations of Be-containing materials and catalysts. Its handling requires strict safety measures due to the toxicity and carcinogenic potential of beryllium compounds; exposure must be avoided, and it is normally stored under inert conditions.