Molecular Organization of 2,1,3-Benzothiadiazoles in the Solid State

Derivatives of 2,1,3-benzothiadiazole (<b>1</b>) are widely used in many areas of science and are particularly valuable as components of active layers in various thin-film optoelectronic devices. Even more effective benzothiadiazoles are likely to result if a deeper understanding of their preferred patterns of molecular association can be acquired. To provide new insight, we have analyzed the structures of compounds in which multiple benzothiadiazole units are attached to well-defined planar and nonplanar molecular cores. Our results show that molecular organization can be controlled in complex structures by using directional S···N bonding of benzothiadiazole units and other characteristic interactions. Moreover, the observed structures are distinctly different from those of analogous arenes. Replacing benzene rings in arenes by thiadiazoles thereby provides a strategy for making new compounds with extended systems of π-conjugation and unique patterns of molecular organization, including the ability to co-crystallize with the fullerenes C<sub>60</sub> and C<sub>70</sub>.