Progress Towards the Synthesis of Novel Graphite Derivatives from a Solution Processable Poly-Cyano Precursor Polymer

Abstract

In this thesis the synthetic progress towards the development of a novel potentially conducting ladder polymer, through the direct writing of a soluble precursor polymer, is presented. The proposed ladder polymer can be synthesized through three steps; the synthesis of a poly-cyano monomer for polymerization, the synthesis of a poly-cyano precursor polymer, and a one step cascading cyclization of a poly-cyano polymer. First addressed is the rather specific palladium catalyzed coupling conditions needed for a single C-C bond forming reaction of highly electron deficient aryl cyanides. The optimization of this coupling reaction, as performed on small oligomers, illustrates that the choice of metal catalyst, supporting ligand, and most especially base have a large influence on the yield. Secondly, a new, highly selective synthetic route to a desired monomer is presented. Third, the precursor polymer is synthesized through the application of the aforementioned optimal conditions. It is observed, through an optimization study, that the highest yielding test couplings do not yield the highest molecular weight polymer. Finally, three cyclization routes, of which only one is a cascading cyclization, are discussed. Photo-physical properties of the isolated fused ring systems show that the larger fused ring oligomers have modest bandgaps and are potential candidates as semi-conducting materials.