Synthesis, characterization, electrochemical behaviour and X-ray crystal structures of nickel(II) complexes with a N2O4 donor set macrocyclic Schiff base ligand

Two nickel(II) complexes of [1 + 1] macrocyclic Schiff base ligand (L) have been prepared by cyclocondensation reactions between 1,3-diamino-2-propanol and 2-[3-(2-formylphenoxy)-2-hydroxypropoxy] benzaldehyde, using NiX2 (X = Br, and I) salts as template agents, and characterized by elemental analyses, IR, molar conductivity and electronic spectra in both solid and solution states. The single-crystal X-ray diffractions of the complexes are also reported that contain nickel(II) ion in a distorted octahedral geometry coordination of N2O3X (X = Br, I and NO3). In all complexes the ligand behaves as a pentadentate ligand. Cyclic voltammetric studies of nickel(II) complexes indicate a quasi-reversible redox wave in the negative potential range.

Graphical abstractSynthesis, characterization, cyclic voltammetry and crystal structure of some nickel complexes with potentially hexadentate macrocyclic Schiff base bearing different counter ions, and the role of anions, hydrogen bonds and π–π stacking on the crystal structures of the complexes have been investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide