Ligand decomposition in the photolysis of copper(II)–amino-acid complexes in aqueous solution

Ligand decomposition following charge-transfer excitation of bis(glycinato)cuprate(II) in aqueous solution gives NH3 and HCHO as the final products in yields equivalent to the reduction of the metal to CuI. An intermediate, observed by flash photolysis, is believed to be the Cu—C-bonded species, CuCH2NH2. The reaction mechanism is discussed for the process in deaerated solution and in O2-saturated solution, where H2O2 is formed in addition to the ligand-decomposition products. Cu(α-alanine)2 shows photolytic behaviour similar to that of the glycine complex.