PHOTOCHEMICAL TRANSFORMATION OF IMINODIACETIC ACID-INDUCED BY COMPLEXATION WITH COPPER(II) IN AQUEOUS-SOLUTION

The photodegradation of copper(II) iminodiacetate (CuIDA) was studied at 20 degrees onochromatic excitation at various pH values. The 1:1 co mplex between copper(II) and iminodiacetic acid was present under our experimental conditions. The initial quantum yield of CuIDA transforma tion, determined by high performance liquid chromatography (HPLC), was low and independent of pH. A redox process was observed giving rise t o Cu-1, HCHO, CO2 and glycine. In the presence of oxygen, the immediat e re-oxidation of copper(I) into copper(II) occurred, giving a very in teresting catalytic aspect to the system. In neutral solution, copper( II) was complexed by glycine (the main photoproduct of CuIDA transform ation) and the photodegradation continued, to give Cu-I, NH4+, CO2 and HCHO.