PHOTOCHEMICAL BEHAVIOR OF COPPER(II) NITRILOTRIACETATE IN AQUEOUS-SOLUTION

The phototransformation of copper(II) nitrilotriacetate (CuNTA) was studied at 20-degrees-C using monochromatic excitation at various pH values. Regardless of irradiation wavelength and pH, the observed phenomenon is a redox process giving rise to Cu(I), HCHO, CO2 and iminodiacetic acid. The quantum yield is low and wavelength dependent with only a slight influence of oxygen. The 1:1 ratio between copper(I) and HCHO formation supports a redox process between Cu(II) and the carboxylate group. The quasi-immediate re-oxidation of copper(I) into copper(II) confers a catalytic effect of interest to the system with regard to the fate of nitrilotriacetate acid (NTA) in the environment.