Assemblies of substituted salicylidene-2-ethanolamine copper(II) complexes: From square planar monomeric to octahedral polymeric halogen analogues

A series of copper(II) complexes with tridentate salicylidene-2-ethanolamine type ligands is described. The complexes were isolated and characterized by single crystal X-ray diffraction, elemental analysis, IR and UV–Vis spectroscopy as well as cyclic voltammetry and magnetic susceptibility measurements. Single-crystal X-ray structure measurements for complexes with unsubstituted as well as 5-chloro and 5-bromo substituted salicylidene-2-ethanolamines demonstrate interesting differences in copper coordination geometry as well as topology of the crystal lattices. It was found, that the nature of the substituent in meta position affects supramolecular assembly in solid state and physicochemical properties such as magnetic susceptibility and redox potentials. Structural differences of studied systems impact the magnetic features by lowering the expected magnetic moments for d9 electronic configuration of copper(II). Cyclic voltammetry measurements show several irreversible reduction and oxidation processes attributed to coordinated ligands and metal centre. The resemblance of the solid state UV–Vis reflectance spectra of octahedral and square planar copper complexes makes them indistinguishable.

A series of copper(II) complexes with tridentate salicylidene-2-ethanolamine type ligands is described. Single-crystal X-ray structure measurements for complexes with unsubstituted as well as 5-chloro and 5-bromo substituted salicylidene-2-ethanolamines demonstrate interesting differences in copper coordination geometry as well as topology of the crystal lattices. It was found, that the nature of the substituent in meta position affects supramolecular assemblies in solid state as well as physicochemical properties.Figure optionsDownload as PowerPoint slide