Manipulating Crystal Packing and Self-Assembly by π-Extended and Isomeric Fused Strategies in Thiophene Ring-Terminated Polycyclic Aromatic Hydrocarbons.

Two series of polycyclic aromatic hydrocarbon isomers (PT-2 and PT-3, and P2T-V and P2T-C) were designed and synthesized by isomerically fusing phenanthrene with thiophene and thieno[3,2-b]thiophene, respectively. All of the new target molecules were confirmed by single-crystal X-ray analysis, and it was found that the solid-state packing can be effectively modulated through a combination of π-extended and isomeric fused strategies. Meanwhile, compared with thiophene ring-terminated isomers PT-2 and PT-3, both having a V-shaped geometry and showing no obvious self-assembly behavior, π-extended unit thieno[3,2-b]thiophene-terminated isomer P2T-V displays a V-shaped structure with moderate self-assembly properties and isomer P2T-C exhibits a C-shaped configuration with further enhanced self-assembly properties.