THE CHEMISORPTION OF POLYIMIDE PRECURSORS AND RELATED MOLECULES ON METAL-SURFACES

A series of molecules including pyromellitic dianhydride (PMDA), m-phenylene diamine (m-PDA), succinic anhydride, phthalic anhydride and aniline were, separately, either chemisorbed at room temperature or condensed at approximately 150 K on a nickel surface and subsequently investigated by X-ray photoelectron spectroscopy and high resolution electron energy loss spectroscopy with a view to determining the nature of the adsorbed species and its orientation at the surface. The anhydride species interact through the anhydride unit, though for dianhydride, PMDA, the second anhydride unit remains intact and directed away from the metal. The amine species interact through a nitrogen atom which undergoes loss of hydrogen. The aromatic ring is aligned almost parallel to the metal surface.