Synthesis, crystal structure and electronic properties of bis(N-2-bromophenyl-salicydenaminato)copper(II) complex

A new series of complexes of the type bis(N-substituted-salicydenaminato)copper(II) (1–9), have been synthesized and characterized by IR, UV–Vis and elemental analysis methods. The molecular structure of bis(N-2-bromophenyl-salicydenaminato)copper(II) (6), was determined using X-ray crystallography. There are two independent molecules in the structure. Each shows a neutral, mononuclear, four-coordinate, square-planar trans-Cu[N2O2] geometry and, in each, the Cu atom and the ligating atoms are coplanar. The chelating N–Cu–O angle is 91.39(11)° for molecule one and 91.20(11)° for molecule two, whereas the non-chelating N–Cu–O angles are 88.61(11) and 88.80(11)°, respectively. The trans-N–Cu–N and trans-O–Cu–O bond angles are 180°. The electronic absorption spectra of copper(II) complexes (1–9), indicate that the d–d band energy is dependent on the nature and position of substituent on phenyl ring of the salicyldenimine ligand. The UV–Vis spectra in various solvents were measured and a relationship between absorption spectra and dielectric constant of the solvents is reported.

Graphical abstractA new series of complexes of the type bis(N-substituted-salicydenaminato)copper(II), (1–9) have been synthesized and characterized. The molecular structure of bis(N-2-bromophenyl-salicydenaminato)copper(II), 6, was determined using X-ray crystallography. There are two independent molecules in the structure. Each shows a neutral, mononuclear, four-coordinate, square-planar trans-Cu[N2O2] geometry and, in each, the Cu atom and the ligating atoms are coplanar. The chelating N–Cu–O angle is 91.39(11)° for molecule one and 91.20(11)° for molecule two, whereas the non-chelating N–Cu–O angles are respectively 88.61(11) and 88.80(11)°. The trans-N–Cu–N and trans-O–Cu–O bond angles are 180°. The trans-N-Cu–N and trans-O–Cu–O bond angles are 180°. The electronic absorption spectra of copper(II) complexes, (1–9) indicate that the d-d band energy is dependent on the nature and position of substituent on phenyl ring of the salicyldenimine ligand.Figure optionsDownload full-size imageDownload as PowerPoint slide