The influence of thiourea and cyanothioacetamide on the anodic properties of copper has been investigated by reflectance infrared spectroscopy, cyclic voltammetry and rotating disk electrode techniques. It is shown that thiourea acts as a ligand for Cu dissolution in aqueous borax whereas cyanothioacetamide reacts with Cu(I) to form an insoluble film at the electrode surface. The main IR peaks observed can be ascribed to the formation of copper complexes and it is shown that IR spectroscopy is a useful tool for the characterisation of metal dissolution products when ligands are present in the solution.