Coordination compound films of 1-phenyl-5-mercaptotetrazole on copper surface

The chemical nature of the coordination compound film formed by reacting PMTA (1-phenyl-5-mercaptotetrazole) with a copper surface has been studied by accelerated corrosion tests, linear sweep voltammetry (LSV), cyclic voltammetry (CV), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). These studies show that, in retarding the corrosion of copper substrate, the film is superior to those formed by TTA (tetrazole), BTA (benzotriazole), HBTA (hydroxybenzotriazole), MBT (2-mercaptobenzothiazole), MBI (2-mercaptobenzo-imidazole), 2-AP (2-aminopyrimidine), IBM (imidazole) and chromates. The surface film has been characterized and found to be a polymeric complex of Cu–PMTA. The mechanism for film formation and relationships between this novel film structure and the observed inhibition behavior are discussed.