Intermolecular Adhesion in Conjugated Polymers

Conjugated polymers are observed to aggregate in solution. To account for this observation we propose a inter-chain binding mechanism based on the intermolecular tunneling of the delocalized $\pi$-electrons occurring at points where the polymers cross. This tunneling mechanism predicts specific bound structures of chain that depend on whether they are semiconducting or metallic. Semiconducting chains should form polyacene-like states exhibiting binding at every other site, while (doped) metallic chains can bind at each site. We also show that solitons co-localize with the intermolecular binding sites thereby strengthening the binding effect and investigate the conformational statistics of the resulting bimolecular aggregates.