Dinuclear Copper(II) Complexes with Distant Metal Centers: Weaker Donor Groups Increase Catecholase Activity

Two dinuclear complexes with CuC distances above 7 A were characterized by X-ray diffraction, EPR spectroscopy, solution speciation, and cyclic voltammetry. Both complexes display EPR spectra typical of dipole-dipole-coupled di-copper(II) complexes. The two complexes presented herein are part of a series of dinuclear complexes with catecholase activity, and they exhibit the highest catalytic efficiencies of the series. This is associated with the weaker donor character of the ligands.