Crystal structure, magnetism and spectroscopy of two strongly antiferromagnetically coupled dinuclear Cu(II) paddlewheel-like compounds with 4-azabenzimidazole as a ligand

摘要

Two dinuclear compounds, [Cu-2(azab)(4)Cl-2]Cl-2(CH3OH)(3) (1) and [Cu-2(azab)(4)Br-2]Br-2(H2O)(1/2) (2) (in which azab = 4-azabenzimidazole), have been synthesized and characterized by infrared spectroscopy and EPR. Also the X-ray structures of both compounds and the magnetic susceptibility have been investigated, and the dinuclear structural details are presented. The geometries of both structures are similar. Each copper(II) ion has a square pyramidal geometry with the basal plane formed by four nitrogen atoms of four bischelating azab molecules in a paddlewheel-like fashion. The apical position is occupied by a chloride or bromide anion, respectively.