Cobalt(II) bromide hydrate (CoBr2•xH2O)-Crystalline

Characteristic




Cobalt(II) bromide (CoBr2) is an inorganic compound. In its anhydrous form, it is a green solid that is soluble in water, used primarily as a catalyst in some processes.




Chemical formula:CoBr2; CoBr2.6H2O; CoBr2.2H2O

Molar mass 218.7412 g/mol (anhydrous);326.74 g/mol (hexahydrate)

Appearance:Bright green crystals (anhydrous);Red-purple crystals (hexahydrate)

Density:4.909 g/cm3 (anhydrous);2.46 g/cm3 (hexahydrate)

Melting point:678 °C (1,252 °F; 951 K) (anhydrous);47 °C (hexahydrate)

Solubility in water:anhydrous:66.7 g/100 mL (59 °C);68.1 g/100 mL (97 °C)

                    hexahydrate:113.2 g/100 mL (20 °C)

Crystal structure:Rhombohedral, hP3




Application




Hygrometers, catalystsCobalt(II) bromide hydrate is mainly used as a catalyst in organic synthesis, like C-metal, C-heteroatom and C-C bond formations, addition to unsaturated bonds, cyclizations, polymerization, oxidations reductions and carbonylations. It reacts with ammonia to form coordination compound bromopentaamminecobalt(III) bromide. It reacts with triphenylphosphine and form complexes of cobalt(II) bromide, which used as a catalyst in organic synthesis.