Stepwise acetylide ligand substitution for the assembly of ethynylbenzene-linked Co(III) complexes

► A family of chloro-ethynylbenzene complexes containing [(cyclam)Co]3+ units are prepared via dehydrohalogenation routes. ► Co:ligand reactant ratios and concentration of exogenous base affect product nuclearity. ► Stepwise ligand substitution is demonstrated, offering control of complex nuclearity. ► Electrochemical characterization shows solution instability of reduced Co-ethynylbenzene complexes.