Extended heterocyclic systems

Abstract

The first chapter of this thesis provides a general introduction to conjugated polymers. The theory underlying the conductive proper- ties of such polymers and their applications are discussed, followed by a brief outline of the aims of the research project. In Chapter 2 the synthetic approaches to pyridine-thiophene and pyridine-furan systems is discussed. A general review of the synthesis of pyridine, thiophene and furan rings, together with synthetic app- roaches to 1,4-diketones, is presented. Chapter 3 describes the synthesis of symmetrical and unsymmetri- cal three ring oligomeric pyridine- thiophenes and pyridine-furans systems, which use 1,4-diketone intermediates. In Chapter 4 the synthesis of the polymeric diketones, poly(py- ridinethiophene) and poly(pyridine-furan) is described, together with a discussion of with their spectral data. Chapter 5 gives full details of the experimental procedures. In Chapter 6 the basicities of the compounds, which have been synthesised in this work, are given together with a general discussion of the data. The Appendix contains the experimental data required for the calculation of the pKa values.