General Syntheses of Tris bidentate Complexes

By far the tris-type complexes such as tris(diamine)cobalt(III), tris(dicarboxylato)-cobaltate(III), and tris(p-ketoacidato)cobalt(III) are best preparwi by oxidizing the cobalt(II) ion in the presence of the ligand in basic form. However, Bauer and Drinkard utilized sodiiun tricarbonatocobaltate(III) trihydrate in a general method to prepare  

Tris(ethylenediamine)cobalt(III) chloride Tris(l,3-diamino-2-propanol x balt(III) nitrate Tris(acetylacetonato)cobalt(III) 

Sodium tris(mercaptoacetato)cobaltate(III) 6-hydrate Tris(ethylenediamine)cobalt(III) tris(salicylato)cobaltate(III) 

Bauer and Drinkard described several features of tricarbonatocobaltate(III) sodium as an intermediate 

This general method was then extended not only to complexes with other bidentate ligands but also to those with a terdentate or a sexadentate ligand, e.g. bidentates, (+)-hydroxymethylenecamphor (-+-)-3-acetylcamphor and (—)-cyclohexanediamine terdentates, 2,3-diaminopropionic add 2,4-diamino-butyric acid l,3-diamino-2-propanol and l-methyl-2,4,6-triaminocyclohexane 

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