Studies on the structure and properties of nickel complexes in a set of amide-based 13-membered macrocyclic ligands

► Nickel chemistry in a set of amide-based 13-membered macrocyclic ligands. ► Crystal structure reveals square-planar geometry around the nickel center. ► Electrochemistry suggests the involvement of metal- and ligand-centered oxidations. ► Effect of electronic substituents (-H, -Me, -Cl, and OMe) on the redox potentials. ► Spectral characterization of electrochemically generated Ni3+ species.