| Abstract: | Infrared reflection-absorption spectroscopy has been used to study the chemical structure of thin films of pyrolyzed polyacrylonitrile (PAN) on copper and aluminium surfaces. The formation of a conjugated C? C?C backbone occurs at temperatures as low as 200°C for PAN on copper, whereas the same reaction on aluminium requires pyrolysis at 300°C in order to be completed. These temperatures are, respectively, about 200 and 100°C lower than those previously reported for bulk PAN. Pyrolysis of PAN on copper at 200°C also results in diffusion of copper atoms (ions) into the polymer network followed by Cu(I)? N°C complexing. Conclusive evidence is obtained for end-on coordination through nitrogen lone pair orbitals of the C?N groups. We propose a chemical structure of PAN on copper that is different to that in the bulk and on aluminium. |
