heksaamminkoboltIII

Heksaamminkobolti(III) is an inorganic coordination compound with the chemical formula [Co(NH₃)₆]Cl₃. It is a salt consisting of the hexamminecobalt(III) cation, [Co(NH₃)₆]³⁺, and three chloride anions, Cl⁻. The central cobalt ion is in the +3 oxidation state and is coordinated by six ammonia ligands. This complex is notable for its stability.

The hexamminecobalt(III) cation is a classic example of a coordination complex. The cobalt(III) ion is octahedrally surrounded by six ammonia molecules. The cobalt-nitrogen bonds are strong, contributing to the inertness of the complex, meaning it reacts slowly with other reagents. This inertness was significant in early coordination chemistry studies.

Heksaamminkobolti(III) typically appears as yellow to orange crystals. It is soluble in water. Its preparation often involves the oxidation of cobalt(II) salts in the presence of ammonia. A common method involves reacting cobalt(II) chloride with ammonia and an oxidizing agent such as hydrogen peroxide or air. Careful control of conditions is necessary to ensure the formation of the desired cobalt(III) complex.

This compound has been used in various applications, including as a laboratory reagent and in studies of coordination chemistry. Its predictable behavior and well-defined structure have made it a valuable tool for understanding the principles of metal-ligand bonding and oxidation states in coordination compounds. Historically, it was important in the development of Werner's coordination theory.