The temperature dependence of some physical properties of cobinamides and cobalamins

Abstract

The temperature dependences of the electronic absorption spectra and the ¹H n.m.r. spectra of the cobinamides and cobalamins are discussed. A conformational change, which does not involve the removal of the 5,6-dimethyl-benzimidazole ligand from the co-ordination sphere of the cobalt is favoured as an explanation of the temperature dependence of these physical properties of the cobalamins.