CHEMISORPTION STUDIES RELATED TO REACTIVE ORGANIC FILM GROWTH

Metal surfaces can be functionalised by the chemisorption of a bifunctional molecule. One functionality is used to form the chemisorption bond, while the second is directed away from the substrate and available for bonding to a second, potentially different, molecule. The process can be continued to grow an organic film in a layer-by-layer manner using controlled deposition and reaction sequences. These possibilities are demonstrated by the interaction of pyromellitic dianhydride with copper and nickel surfaces and its subsequent reaction with aniline and p-phenylene diamine to form imide links via the intermediate amic acid. The chemisorption behaviour of pyromellitic dianhydride which involves opening one of the anhydride rings, loss of CO and formation of a surface carboxylate link has been characterised by X-ray PES and EELS, and supported by similar measurements on the chemisorption of phthalic anhydride and benzoic acid on a copper surface. The reactions are also followed by these techniques.