A novel octanuclear copper(II) compound: Synthesis, crystal structure and magnetic properties

The crystal structure of a novel octanuclear copper(II) complex containing the bidentate 1,10-phenanthroline ligand (abbreviated as phen) with cooperative carbonato and hydroxido bridging ligands, [Cu8(phen)12(μ3-OH)2(μ-OH)2(μ3-CO3)2](CF3SO3)8(DMF)2(H2O)0.5 (1) (when DMF = N,N-dimethylformamide) is described. Compound 1 consists of two symmetry-related di-μ-hydroxido-bis(1,10-phenanthroline)copper(II) groups which held together by long Cu–O(H) bonds, creating a Cu2(OH)2 core of a tetranuclear hydroxido-bridged copper(II) unit, further coordinated with trans-axially at Cu(3) and Cu(3)A by [μ3-carbonato-tetrakis(phen)dicopper(II)] moieties. The di-μ-hydroxidocopper(II) species play an important role for the apparent ferromagnetic interaction with the Cu–OH–Cu angles (θ) of 95.8(2)° and 93.5(1)°. The spectroscopic properties (IR, reflectance and EPR spectra) and the magnetic susceptibility data of this compound are investigated and compared with other related polynuclear copper(II) compounds.