Abstract
beta-Unsubstituted oligothiophenes with up to 13 thiophene units are described. These represent the longest oligomers ever reported in this class. In solution, those compounds show a temperature- and concentration-dependent aggregation behavior. Absorption, fluorescence, dynamic light scattering, and cryo-transmission electron microscopy investigations reveal the formation of wormlike aggregates several hundred nanometers in length and ca. 5 nm in width.