text: Compounds of cobalt in the +3 oxidation state exist, such as cobalt(III) fluoride , nitrate , and sulfate ; however, cobalt(III) chloride  is not stable in normal conditions, and would decompose immediately into  and chlorine.
  On the other hand, cobalt(III) chlorides can be obtained if the cobalt is bound also to other ligands of greater Lewis basicity than chloride, such as amines.  For example, in the presence of ammonia, cobalt(II) chloride is readily oxidised by atmospheric oxygen to hexamminecobalt(III) chloride:
  :4 ·6 + 4 Cl + 20  +  → 4  + 26 
  Similar reactions occur with other amines.  These reactions are often performed in the presence of charcoal as a catalyst, or with hydrogen peroxide  substituted for atmospheric oxygen. Other highly basic ligands, including carbonate, acetylacetonate, and oxalate, induce the formation of Co(III) derivatives. Simple carboxylates and halides do not.
  Unlike Co(II) complexes, Co(III) complexes are very slow to exchange ligands, so they are said to be kinetically inert. The German chemist Alfred Werner was awarded the Nobel prize in 1913 for his studies on a series of these cobalt(III) compounds, work that led to an understanding of the structures of such coordination compounds.