Preparation and physical properties of alkylcobalt complexes of the coenzyme B12 model complex RCo[C2(DO)(DOH)pn]X

Article abstract of DOI:10.1021/ic50217a010

A detailed and convenient three-step synthesis of Co[C₂(DO)(DOH)_pn]I₂ (IV) is described beginning with readily available starting materials. The 70-80% reduction of the diiodide IV to 1-g quantities of the crystalline Co(I) Co[C₂(DO)(DOH)_pn](CO) (V) is presented as are the ¹³CO-exchange reaction of V and its alkyl halide oxidative additions as a clean and efficient synthesis of RCo[C₂(DO)(DOH)_pn]X complexes. Transformation of the alkyl halide adducts to [RCo[C₂(DO)-(DOH)_pn](base)]⁺PF₆ ^- and BF₂-bridged derivatives is also described. Some of the key physical properties of the alkyl-cobalt complexes are also presented including their extent of axial halide dissociation, the pyridine binding constant of the methyl derivative, the photochemical cleavage of the alkyl-cobalt bond in the presence of HMn(CO)₅, and the properties of the oxime O?H?O bridge.