CHIMIA (Mar 2001)
Poly(triacetylene)s: A New Class of Linearly ?-Conjugated Oligomers and Polymers with an All-carbon Backbone
Abstract
Linearly ?-conjugated polymers are intensively investigated in both academia and industry for a diversity of advanced materials applications. Polyacetylenes (PAs) and poly(diacetylene)s (PDAs) were among the earliest investigated linearly ?-conjugated polymers possessing an all-carbon backbone. They actually represent the first members in an entire progression of linear all-carbon polymers which starts with polyacetylene and ultimately extends to carbyne. Here, we describe the discovery and systematic investigation of poly(triacetylene)s (PTAs), the third class of compounds in this progression. We report both the preparation of longer-chain polydisperse PTA polymers as well as the synthesis, characterization, and physical study of monodisperse oligomers with record lengths extending up to 18 nm. We show how molecular properties evolve into the saturation range with increasing oligomeric length and report several direct determinations of the effective conjugation length (ECL), i.e. the oligomeric length at which saturation of molecular properties occurs. Finally, we present a new class of hybrid oligomers and polymers, with a diversity of chromophores inserted as functional spacers into the PTA backbone for further enhancement of optoelectronic properties.
