PHOTOCHEMICAL REDOX REACTIONS OF INNER-SPHERE COPPER(II)-DICARBOXYLATE COMPLEXES : EFFECTS OF THE DICARBOXYLATE LIGAND STRUCTURE ON COPPER(I) QUANTUM YIELDS

Studies were carried out on the photochemical redox reactions of a series of structurally related inner-sphere Cu(II)/dicarboxylate complexes in aqueous solution (N2-purged), using steady-state illumination. Cu(I) quantum yields (313 nm) of these systems were characterized with respect to the effects of copper(II) speciation, mainly considering the effect of the dicarboxylate structure on the Cu(I) quantum yield. For each solution composition, which corresponds to a unique Cu(II) speciation, the Cu(II)-based molar absorptivity (eCu(II), M-1 cm-1) and the quantity ΦCu(I)eCu(II) (where ΦCu(I) represents the experimental Cu(I) quantum yield) were determined from experiments. This experimental information (eCu(II) and ΦCu(I)eCu(II)) was explicitly combined with the calculated equilibrium Cu(II) speciation (based on critically reviewed thermodynamic data) in a quantitative model to determine molar absorptivities (eCuL) and Cu(I) quantum yields (ΦCu(I),CuL) of the CuL complexes, where L represents the dicarboxy...