CHAPTER 8: Poly(p-phenyleneethynylene)s and Poly(aryleneethynylene)s

Development of Pd-catalyzed and alkyne metathesis methods for the synthesis of a series of poly(aryleneethynylene)s (PAE) are discussed and presented. Depending upon structure and monomers used, either acyclic diyne metathesis (ADIMET) or Pd-catalyzed couplings of the Sonogashira type are optimal to get to the corresponding PAEs. For dialkyl-PPEs ADIMET is the most attractive way to make high molecular weight polymers of high purity, while for highly functionalized and alkoxy-PPEs and PAEs with heterocyclic building blocks often Pd-catalysis is more successful. PAEs exhibit a whole host of different properties and are workhorses as sensory polymers for the detection of bacteria, proteins and explosives. Their modular synthesis combined with their attractive and unique fluorescence properties makes these materials nowadays invaluable in sensing, etc., applications. This chapter deals with, and focuses on the details of the synthesis of the PPEs and PAEs.