Structural effects on electrochemical properties of the carboxamide complexes [NiII(Mebpb)] and [NiII(Mebqb)]

Two Ni(II) complexes of the dianionic ligands, Mebpb2−, [H2Mebpb = N,N′-bis(pyridine-2-carboxamido)-4-methylbenzene] and Mebqb2−, [H2Mebqb = N,N′-bis(quinoline-2-carboxamido)-4-methylbenzene] have been synthesized and characterized by elemental analyses, IR, and UV–Vis spectroscopy. The crystal and molecular structures of [Ni(Mebpb)], (1), and [Ni(Mebqb)], (2), were determined by X-ray crystallography. Both complexes exhibit distorted square–planar NiN4 coordination figures with two short and two long Ni–N bonds (Ni–N ∼1.84 and ∼1.95 Å, respectively). The electrochemical behavior of these complexes with the goal of evaluating the structural effects on the redox properties has been studied.

Graphical abstractTwo new Ni complexes containing pyridine-2-carboxamide ligands, [NiII(Mebpb)] and [NiII(Mebqb)], have been synthesized and structurally characteriazed. The relation between the structural changes and redox potentials of these nickel(II) complexes in going from Mebpb2− to Mebqb2− are discussed and compared with those already reported in the literature.Figure optionsDownload full-size imageDownload as PowerPoint slide