Synthesis and Characterization of Three Pentacene Derivatives

Abstract

The addition of substituents at the 6,13-position improved the solubility and stability of pentacene, making it possible to use the derivatives in spin coating of organic field-effect transistors (OFETs). Three pentacene derivatives, 6,13-bis(m-tolyl)pentacene (MP), 6,13-bis(4-butylphenyl)pentacene (BP), and 6,13-bis((4-butylphenyl)ethynyl)pentacene (BPEP) were synthesized, and their properties were investigated. 6,13-Pentacenequinone and organolithium were used in the preparation of 6,13-dihydropentacene at 0 °C, and pentacene derivatives were synthesized with SnCl₂/HCl as reducing agent, to reduce 6,13-dihydropentacene at room temperature. The structure of the derivatives was characterized using NMR. The thermal stability, photochemical properties, and electronic structure of the three compounds were investigated using TGA, cyclic voltammetry, and UV–Vis. BPEP was also characterized using X-ray diffraction and atom force microscopy. BPEP was used to fabricate an OFET device using spin coating. The device showed a mobility of 0.07 cm² V s⁻¹ at V _th = − 10 V and I _ON/I _OFF = 10².

Keywords

Organolithium / Reduction reaction / Mobility / OFET / Spin coating

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