Chemical Properties
The green anhydrous salt is prepared by dehydration of the red hexahydrate or by the action of bromine on heated cobalt. It is very soluble in water and soluble in many polar organic solvents; it deliquesces in moist air to a red solution. The hexahydrate crystallizes from aqueous solution at room temperature; it melts at 100°, evolving water and forming the purple dihydrate.
Chemical Properties
Reddish violet crystalline powder
Uses
Cobalt(II) bromide is used as a catalyst in organic synthesis. It is used as a precursor in the production of ethylsulfanyl)porphyrazinato)cobalt(II), which gives the possibility of intermolecular ferromagnetic interactions.
Uses
Used in the preparation of a new complex, Co(OESPz), which offers the possibility of intermolecular ferromagnetic interactions.1
Preparation
Cobalt(II) bromide (CoBr2) is on its anhydrous form a green solid that is soluble in water, used primarily as a catalyst in some processes. Cobalt(II) bromide can be formed as a hydrate by the reaction of cobalt hydroxide with hydrobromic acid.
Co (OH) 2 (s)+2HBr (aq)→CoBr2.6H2O(aq)
General Description
COBALT(II) BROMIDE is a red violet crystalline solid. COBALT(II) BROMIDE is soluble in water. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. COBALT(II) BROMIDE is used as a catalyst in the production of other chemicals.
Air & Water Reactions
Water soluble.
Reactivity Profile
Acidic salts, such as COBALT(II) BROMIDE, are generally soluble in water. The resulting solutions contain moderate concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. Many of these compounds catalyze organic reactions. When heated to decomposition can give off highly toxic fumes of Br [USCG, 1999].
Health Hazard
SOLID: Irritating to skin and eyes. Harmful if swallowed.
Fire Hazard
Not flammable. POISONOUS FUMES ARE PRODUCED WHEN HEATED TO DECOMPOSITION. When heated to decomposition can give off highly toxic fumes of Br.
Purification Methods
Crystallise it from water (1mL/g) by partial evaporation in a desiccator. The anhydrous salt is soluble in EtOH, Me2CO, MeOAc to form blue-coloured solutions. [Glemser in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol II p 1517 1965.]
