MONO-NUCLEAR AND DINUCLEAR COBALT(III) COMPLEXES WITH S-TYROSINE

In a direct synthesis, by oxidation of cobalt(II) to cobalt(III) by ox ygen in the presence of the lithium salt of S-tyrosine, the following isomers of the tris(S-tyrosinato)cobalt(III) complex were obtained: De lta-(-)(589)-facial, Lambda-(+)(589)- and Delta-(-)(589)-meridional, a nd (-)(589)-anti(N)-Delta-cis(N), cis(O)-Lambda-cis(N), di-mu-hydroxo- tetrakis(S-tyrosinato)dicobalt(III). Their composition was established by microanalysis, and their structure by electronic absorption, CD an d C-13 NMR spectra. Finally, it was found that Delta-mer-tris(S-tyrosi nato)cobalt(III) described earlier is a mixture of Delta and Lambda di astereomers of the complex.