Liquid-Crystalline Naphthalene and Perylene Bisimides with a D<sub>2</sub>–π<sub>2</sub>–A Architecture for High-Mobility Organic Field-Effect Transistors
Vinod Kumar Vishwakarma, Mrinmoy Roy, Rajan Singh, D. S. Shankar Rao, Roy Paily, Ammathnadu S. Achalkumar
Abstract
We designed and synthesized four naphthalene and perylene bisimide-based imidazole-containing liquid-crystalline (NI and PI) derivatives based on a donor−π–acceptor−π–donor (D 2 –π 2 –A) architecture. These compounds bear 10 flexible peripheral chains to ensure liquid crystallinity and solution processability making them suitable to use as organic semiconductors. All four compounds stabilized different columnar phases. Higher thermal stability and lower band gaps were also observed in both NI and PI derivatives. NI derivatives showed larger Stokes shifts, while PI derivatives exhibited very high molar extinction coefficients. Two solution-processable liquid-crystalline compounds ( NI-12 and PI-12 ) were utilized for the fabrication of organic field-effect transistors, exhibiting a hole mobility of 1.99 cm 2 /V·s for NI-12 and 0.63 cm 2 /V·s for PI-12 derivatives at room temperature in normal air conditions.