Vitamin organocobalt complexes

Certain groups of organocobalt(III) complexes have been dealt with in previous reviews. The organo-corrinoids have been mentioned in all reviews on vitamin B, 2 since 1961, when the coenzyme form was identified as an organometallic compound [see, for example, (79, 178) and references therein]. The literature on the corrinoids is too extensive to be treated comprehensively here and for details and references readers are referred to the book on The Inorganic Chemistry of Vitamin B,2 (136)certain other aspects of the organometallic chemistry of cobalt corrinoids are treated elsewhere (137). The pentacyanides were reviewed in 1967 (105), the DMG complexes (cobaloximes) in 1968 (145), and some aspects of salen, BAE, and related complexes in 1970 (17). 

The chapter deals with complexes formed with groups IV (C, Si), V (N, P, As) and VI (O, S, Se) donor atoms with the following exceptions. Organocarbon chemistry including organocobalt(III) model systems for vitamin B12 have been considered by Kemmitt and Russell in the companion series... 

Cobalt is an element known from cobalt blue, cobalt irradiation, metals in special steels and magnetic materials, etc. Cobalt is one element of vitamin B12 which is one of the indispensable human nutrients. Generally, cobalt is widely studied in the chemistry of complexes since it is liable to form complex salts. But organocobalt compounds are not known unlike the complex salts. However, recently their organosynthetic uses have been rapidly increasing. 

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