Mixed-ligand cobalt(III) complexes derived from bis(dehydroacetato)ethylenediimine

Summary A hydroxocobalt(III) complex (1a), has been obtained by reaction of bis(dehydroacetato)ethylenediimine (H₂dhaen) with cobalt(II) hydroxide or acetate in the presence of air. Addition of a second complexing agent leads to the formation of a series of mixed-ligand complexes (2)-(26) having either the trans- or cis- configuration. In the cis- complexes, the quadridentate ligand dhaen adopts a nonplanar conformation. Configurations are distinguishable from characteristic differences in the electronic and n.m.r. spectra.