Beryllium fluoride

Beryllium fluoride is the chemical compound with the formula BeF2. It is the beryllium compound with the greatest amount ionic character (due to the high electronegativity of fluorine), but even still it is not considered ionic by many chemists. This synthetic material is the principal precursor for the manufacture of beryllium metal, which is obtained by reduction of BeF2 at 1300°C:


 * BeF2 + Mg &rarr; Be + MgF2

Molecular BeF2, as found in the gas-phase, is isoelectronic with CO2 and SiO2. The condensed form adopts a polymeric structure resembling that of the mineral crystobalite. The difference between the ambient temperature structures of BeF2 and CO2 reflects the decreased tendency of alkali metals to form multiple bonds. Gaseous BeF2, after 1160 °C, is a linear molecule with a Be-F distance of 177 pm. An analogy exists between BeF2 and AlF3: both adopt extended structures at mild temperature.

Applications
Beryllium fluoride is used in biochemistry, particularly protein crystallography, since it binds in some of the same ways as phosphate does. ADP and beryllium fluoride together tend to bind to ATP sites and inhibit protein action, making it possible to crystallise proteins in the bound state.

Safety
All beryllium compounds are highly toxic. Beryllium fluoride is very soluble in water and is thus absorbed easily; as mentioned above, it inhibits ATP uptake. The LD50 in mice is about 100mg/kg by ingestion and 1.8mg/kg by intravenous injection.