Liquid-Crystalline Naphthalene and Perylene Bisimides with a D₂–π₂–A Architecture for High-Mobility Organic Field-Effect Transistors

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.

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

“…Phase sequence (°C) a HOMO (eV) LUMO (eV) with an anisotropy of the charge carrier mobility (parallel vs perpendicular to the columnar axis) of up to ten orders of magnitude [3][4][5][6][7]. In 1994, Adam and collaborators obtained a holemobility of up to 0.1 cm 2 V −1 s −1 for a triphenylene-based columnar liquid crystal [8], motivating intense research activity to understanding charge transport in columnar mesophases [9][10][11][12][13][14].…”

Bay-Substitution of Perylene Bisimides with Bidentate Nucleophiles: The Case of Aryloxide Anions

“…Perylene bisimides (PBIs) are one of the most versatile and extensively employed groups of functional dyes. Their distinctive properties, including remarkable electron affinities, near-unity fluorescence quantum yields, thermal and photochemical robustness, make them an integral part in a wide range of applications in areas such as photocatalysis, organic photovoltaics, − sensing, organic field effect transistors, and OLEDs. , While chemical modifications at the imide position of PBIs typically affect their solubility, , the introduction of substituents at the bay and ortho positions (Scheme a) offers an efficient means to finely tune the optical and redox properties of these dyes. , Furthermore, covalent modifications in the bay region often induce a twisted conformation of the π-conjugated framework, significantly influencing the molecular arrangement in condensates, which is important for their application in the development of novel functional materials. , …”