Abstract: | In recent years, low‐bandgap polymers have attracted much attention in a wide range of fields. The synthesis of these compounds has been focused on three factors according to the Roncali bandgap theory: 1) the degree of bond‐length alternation (E δr), 2) the aromatic resonance energy of the cycle (E Res), and 3) the substituted groups (E Sub). Herein, we have designed and prepared low‐bandgap polymers in a different way by using the factors E θ (the deviation from planarity of the polymer chain) and E Int (the interaction of the molecular chains in the solid state). Thus, three polycyclic aromatic hydrocarbons with different spatial constructions, based on hexaphenylbenzene derivatives, were prepared in this work: linear ( P1‐OX ), V ( P2‐OX ), and zigzag ( P3‐OX ) types. These well‐defined polymers exhibited interesting optical and electrochemistry behavior due to their different extents of planarity. Matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry gave the incremental orderly molecular weight distributions of P1 , P2 , and P3 , the weight‐average molecular weights ( ) of which were 9000, 5500, and 69 000, respectively. Their lamellar layer structures and π–π intermolecular stacking were demonstrated by using two‐dimensional grazing‐incidence X‐ray diffraction, which revealed the edge‐on chain conformation. Finally, the materials were perfectly adapted to fabricate high‐performance organic field‐effect transistor devices, which revealed that these compounds could have great prospects as semiconductors. |