Synthesis, structure, spectroscopic, magnetic and electrochemical studies of a rare syn–anti acetate-bridged copper(II) complex

The structure, spectroscopy and electrochemical properties of a novel dinuclear copper(II) complex, [{Cu(phen)2}2(μ-CH3COO)][PF6]3 where phen = 1,10-phenanthroline, is reported. The crystal structure contains two independent Cu(II) ions, with different geometry around each copper center, which are bridged by an acetate anion. The acetate-bridged ligand shows a syn–anti coordination mode with a trigonal bipyramidal geometry for the Cu(1) center and a distorted square-based pyramidal geometry for the Cu(2) center. The angular structural index parameter τ for Cu(1) and Cu(2) is 0.9 and 0.33, respectively. The copper(II) atoms display a different geometry with a N4O chromophore group and with Cu–O distances of 1.993(5)–1.996(5) Å and Cu–N distances which vary from 1.980(5) to 2.161(6) Å. The intra Cu…Cu separation is 4.9904(5) Å. The effective magnetic moment (μeff) of the complex was measured by the Evans method. The cyclic voltammogram of [{Cu(phen)2}2(μ-CH3COO)][PF6]3 shows two waves at positive potential which are assigned to the two Cu(II/I) reduction couples.

The structure, spectroscopy and electrochemical properties of a novel dinuclear copper(II) complex, [{Cu(phen)2}2(μ-CH3COO)][PF6]3, is reported. The crystal structure contains two independent Cu(II) ions with different geometries around each copper center which are bridged by an acetate anion. The acetate bridging ligand between the two Cu(II) centers shows a syn–anti coordination mode with a trigonal bipyramidal geometry for the Cu(1) center and a distorted square-based pyramidal geometry for the Cu(2) center.Figure optionsDownload as PowerPoint slide