New Bi-Nuclear Nickel(II) Complex-Based Salen Schiff Base: Synthesis, Crystal Structure, Spectroscopic, Thermal, and Electrical Investigations

In this study, a new bi-nuclear nickel complex [Ni2HL2(EtOH)2](Cl)(EtOH) of a Schiff base ligand, 2-[3-[2-hydroxybenzylideneamino]propyliminomethyl]phenol, was synthesized and characterized using UV/Vis, IR, HRMS, and TGA/DTA analysis. The molecular structure of the obtained complex was corroborated by the single crystal X-ray diffraction technique. It was found in the complex that two molecules of the ligand coordinate with two nickel atoms through azomethine-N and phenoxy-O, resulting in 6-coordinate distorted octahedral geometry, in which two ethanol molecules occupy the axial positions. The dielectric and electrical properties of the obtained samples were studied by impedance spectroscopy at different frequencies (from 1 Hz to 1 MHz) in the temperature range 298–343 K. It is found that the electrical conductivity of the Ni(II) complex is lower than that of the free ligand H2L, suggesting that the complexation traps the charge carriers contained in the ligand.