Cobalt a structural analog to ferrocene, with cobalt in place of iron. Cobaltocene is much more sensitive to oxidation than ferrocene. Cobalt carbonyl (Co(CO)) is a catalyst in carbonylation and hydrosilylation reactions. Vitamin B (see below) is an organometallic compound found in nature and is the only vitamin that contains a metal atom. An example of an alkylcobalt complex in the otherwise uncommon +4 oxidation state of cobalt is the homoleptic complex (Co(1-norb)), a transition metal-alkyl complex that is notable for its stability to β-hydrogen elimination. The cobalt(III) and cobalt(V) complexes [Li(THF)][Co(1-norb)] and [Co(1-norb)][BF] are also known. Co is the only
Cobalt B, the primary biological reservoir of cobalt as an ultratrace element. Bacteria in the stomachs of ruminant animals convert cobalt salts into vitamin B, a compound which can only be produced by bacteria or archaea. A minimal presence of cobalt in soils therefore markedly improves the health of grazing animals, and an uptake of 0.20 mg/kg a day is recommended because they have no other source of vitamin B. In the early 20th century, during the development of farming on the North Island Volcanic Plateau of New Zealand, cattle suffered from what was termed "bush sickness". It was discovered that