CHEMISORPTION STUDIES RELATED TO REACTIVE ORGANIC FILM GROWTH

Metal surfaces can be functionalised by the chemisorption of a bifunct ional molecule. One functionality is used to form the chemisorption bo nd, 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 u sing 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 an d p-phenylene diamine to form imide links via the intermediate amic ac id. The chemisorption behaviour of pyromellitic dianhydride which invo lves 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 phthal ic anhydride and benzoic acid on a copper surface. The reactions are a lso followed by these techniques.