ABSTRACT Non‐planar aromatic hydrocarbons display distorted π‐frameworks that give rise to unique optoelectronic properties. Among the different strategies for generating non‐planar aromatic hydrocarbons, steric overcrowding has afforded numerous twisted structures displaying helical or alternate twists, whereas bent structures remain rare. Herein, we report a pyrene‐fused azaacene derivative in which eight strategically positioned phenyl substituents enforce bending of the aromatic core rather than twisting, generating a negatively curved, saddle‐shaped structure. Single‐crystal x‐ray diffraction reveals large deviations from planarity with bend angles of 41° and 34°, stabilised by intramolecular π‐π stacking between facing phenyl rings.
Carini et al. (Thu,) studied this question.