Metathesis ring-opening polymerisation of some heteropolycyclic alkenes : an indirect approach to the synthesis of a new heterosubstituted conjugated polymer
This thesis consists of four chapters. The first chapter outlines the origins and objectives of the work reported. The second chapter discusses olefin metathesis and describes the synthesis, characterisation and investigation of the ring-opening polymerisation of some heterosubstituted cycloalkenes in an attempt to prepare a polymer which would act as a precursor leading to a heterosubstituted conjugated polymer. Keto-substituted derivatives of bicyclo[2,2,l] hept- 2-ene were investigated initially and were found to be poor monomers for metathesis ring-opening polymerisation. However, cycloalkenes bearing chlorocarbonate substituents were found to be readily ring-open polymerised by a typical metathesis catalyst system, WC1(_6)/SnMe(_4) at 70ºC. The third chapter describes the conversion of the pre cursor polymer synthesised as described in Chapter Two into a new heterosubstituted conjugated polymer. This new polymer was found to be readily oxidised, and to have similar electrical properties to other poly(acetylene) derivatives bearing electron- withdrawing substituents. Finally, the fourth chapter describes attempts to synthesise block copolymers by metathesis ring-opening polymerisation using a solvent-free catalyst system.