Synthesis, structure, and physicochemical properties of triply-bridged binuclear copper(II) complex [Cu2Phen2(µ-CH3CO2)2(µ-OH)]2[B10Cl10

Abstract

The reaction between copper(II) acetate and Phen in the presence of [B10Cl10]2− anion affords mononuclear copper(II) complex [CuPhen2(CH3CO2)]2[B10Cl10]·[CuPhen(CH3CO2)2]. Continuous heating of the latter in DMSO results in triply-bridged binuclear copper(II) complex [Cu2Phen2(CH3CO2)2OH]2[B10Cl10] isolated from the reaction solution as a DMSO solvate hydrate [Cu2Phen2(CH3CO2)2OH]2[B10Cl10]·3DMSO·0.5H2O. Both complexes are studied by IR, 11B NMR, and X-ray diffraction; the binuclear complex is studied by 35Cl NQR and EPR spectroscopies as well as X-ray powder diffraction technique. Despite the short Cu−Cu distance revealed by X-ray diffraction analysis in the binuclear cationic complex (3.234 Å), no interactions between copper atoms are detected by EPR spectroscopy. According to 35Cl NQR studies, chlorine atoms bound with equatorial boron vertices of the boron cage participate in non-covalent interactions with H atoms of Phen molecules.