Beryllium bromide is the chemical compound with the formula BeBr2. It is very hygroscopic and dissolves well in water. The Be(2+) cation, which is relevant to BeBr2, is characterized by the highest known charge density (Z/r = 6.45), making it one of the hardest cations and a very strong Lewis acid.

Preparation and reactions

It can be prepared by reacting beryllium metal with elemental bromine at temperatures of 500 °C to 700 °C: When the oxidation is conducted on an ether suspension, one obtains colorless dietherate: The same dietherate is obtained by suspending beryllium dibromide in diethyl ether: This ether ligand can be displaced by other Lewis bases.is ether ligand can be displaced by other Lewis bases. Beryllium bromide hydrolyzes slowly in water: BeBr2 + 2 H2O → 2 HBr + Be(OH)2

Structure

Two forms (polymorphs) of BeBr2 are known. Both structures consist of tetrahedral Be2+ centers interconnected by doubly bridging bromide ligands. One form consist of edge-sharing polytetrahedra. The other form resembles zinc iodide with interconnected adamantane-like cages.

Safety

Beryllium compounds are toxic if inhaled or ingested.