UV-Vis and EPR spectroscopic study of copper(II) complexes with bis(benzimidazol-2-yl) ligands

Abstract

Copper(II) complexes with bis(benzimidazol-2-yl) ligands of the type Bz(CH 2) n -X-(CH 2) n Bz (where Bz=benzimidazol-2-yl; XO, S or CH 2; n=1, 2) have been characterized in solution by UV-Vis and EPR spectroscopy. Mono complexes with O or S donor atom containing ligands have square-pyramidal stereochemistries, while bis complexes have pseudo-octahedral geometries with four nitrogen donors in the equatorial plane and the two heteroatoms occupying the apical positions. The mono and bis complexes with the ligand having XCH 2 and n=2 have distorted octahedral geometries with two molecules of solvents involved in the apical positions. The experimental results on the complexes with the ligand having XCH 2 and n=1 suggest that this ligand behaves as monodentate.