| Chapter 1 describes methodology for the preparation of arylene-vinylene oligomers. Chemistry for both the thiophene-based and phenyl-based systems was evaluated. Wittig and Heck reactions were found to be useful for the preparation of the desired thiophene-vinylene systems, with the Wittig reaction generally giving superior results. These same Wittig and Heck conditions were found to be also useful for preparing the analogous phenylene-vinylene systems, with the Heck reaction generally giving superior results. Both routes were shown to be easily adaptable to a divergent/convergent strategy and to solid-supported synthetic methods. Additionally, the synthesis of thousands of discrete oligomers for LED applications by a novel combinatorial solid-supported strategy was proposed and described.; Chapter 2 describes work towards developing a synthetic template oligomerization system. Both non-covalent and covalent interactions were evaluated. Model templating systems, both linear and cyclic, were prepared and used to attempt intramolecular templated oligomerization to achieve well-defined macromolecules. Initial chemistry evaluated involved palladium-catalyzed cross-coupling reactions for the oligomerization step. Unfortunately, the desired intramolecular templated reaction was found to be slow compared to the competing tendency toward polymerization.; Chapter 3 describes cyclic oligomer synthesis using solid-supported chemistry. A novel coupling/cyclization strategy was explored for the preparation of hexa-aryl cyclic oligomers by palladium-catalyzed cross-coupling reactions. Competing inter-site reactions were found problematic during the synthesis. The use of a highly cross-linked polystyrene resin was evaluated in order to eliminate these inter-site reactions, resulting in interesting catenane-like structures, with the produced cyclic oligomer physically entangled with the polymer network. |
