ChemInform Abstract: Highly Stabilized Copper(III) Complexes.
Abstract
The reaction of strongly donating polyanionic chelating ligands with copper acetate hydrate in ethanol yields the Cu(III) complexes (I)-(III), which are isolated as salts of noncoordinating cations.
ChemInform Abstract
The reaction of strongly donating polyanionic chelating ligands with copper acetate hydrate in ethanol yields the Cu(III) complexes (I)-(III), which are isolated as salts of noncoordinating cations. The ligands in the complexes (I) are known, the other ligands (IX) and (XII) are synthesized as shown in the scheme. The X-ray crystal structure of one example, the tetraphenylphosphonium salt of (IIb)(space group P21/n, Z=4), is determined. The metal center is found in a square-planar environment with normal bond distances and angles for the Cu(III) formulation. Cu(III/II) couples are highly sensitive to ligand environments. The trend in formal potentials as the aromatic groups in these type of ligands are replaced by aliphatic groups indicates that oxidation of each Cu(II) complex is metal-centered. The formal potentials of the Cu(III/II) couples vary over a range of more than 1.1 V. Alkoxide ligands are much stronger donors than phenoxide ligands.
