Photochemistry of macrocyclic copper(II) complexes. Photoinduced redox reactions of Cu[13-AtH]2+1

The photochemical reactivity of the Cu[13-AtH]2+ complex is noticeable only for ultraviolet irradiations (254 to 370 nm). Photolyses, carried out in the presence of various alcohols, produced aldehydes or ketones. Two Cu(II) macrocyclic complexes, one characterized as Cu[Me2[13]monoeneN4]2+, were products of the reaction. The dependence of the quantum yields on experimental variables (acid concentration, scavenger concentration, light intensity, excitation wavelength) is explained in terms of a proposed reaction mechanism. The primary product, a Cu(III) cation--ligand radical, was postulated by a comparison with the behavior already reported for Cu[[14]dieneN4]2+