Tuning crystalline solid-state order and charge transport via building-block modification of oligothiophenes

The packing structure of a series of oligothiophenes is tuned via terminal substitution (see figure). The structural changes dramatically alter intermolecular interactions and charge-transport properties, as measured by elastomeric singlecrystal field-effect transistors. Electronic structure calculations reveal the sensitivity of the transport efficiency to orbital nodal alignment, as correlated to the observed trend in field-effect mobilities.