Synthesis, processing and properties of conjugated polymer networks

Despite the diverse research activities focused on the chemistry, materials science and physics of conjugated polymers, the feature of conjugated cross-links, which can provide electronic communication between chains, has received little attention. This situation may be a direct consequence of the challenge to introduce such links while retaining adequate processability. Focusing on recent studies of materials for which charge transport or electrical conductivity data are available, this feature article attempts to present an overview of the synthesis, processing and electronic properties of conjugated polymer networks. For the purpose of this discussion, two distinctly separate architectures-featuring covalent cross-links on the one hand and non-covalent organometallic bridges on the other-are treated in separate sections. The available data indicate that cross-linking can have significant benefits for intermolecular charge transfer if the polymers are carefully designed.