Controlling Conformations of Conjugated Polymers and Small Molecules: The Role of Nonbonded Interactions

The chemical variety present in the organic electronics literature has motivated us to investigate potential nonbonding interactions often incorporated into conformational ``locking'' schemes. We have examined a variety of potential interactions, including oxygen-sulfur and nitrogen-sulfur, using accurate quantum-chemical wave function methods on a selection of high-performing conjugated polymers and small molecules. In addition, we evaluate a set of nonbonding interactions occurring between various heterocyclic and pendant atoms taken from a group of representative pi-conjugated molecules. From our survey, it is determined that while many nonbonding interactions possess weak binding capabilities, hydrogen bonding interactions, namely oxygen-hydrogen and nitrogen-hydrogen, are alone in inducing conformational control and enhanced planarity along a polymer or small molecule backbone at room temperature.