Anthracene−Pentacene Dyads: Synthesis and OFET Characterization. Issue 5 (13th May 2020) - Hauschild, Miriam
Abstract: The synthesis of a series of unsymmetrical derivatives of pentacene appended with functionalized anthracene moieties is reported. These anthracene−pentacene dyads have been characterized by UV‐vis spectroscopy and cyclic voltammetry to examine their electronic properties. X‐ray crystallographic analysis was used to examine the solid‐state features of anthracene−pentacene dyads 1 a –d with H−, F−, Cl−, and Br− substituents on the 9‐position of anthracene, and shows that the packing arrangement of anthracene−pentacene derivatives 1 b, d, e are remarkably similar irrespective of the presence of fluoride, bromide or methyl substituents. The pentacene−anthracene dyads have been incorporated into OTFTs to evaluate their semiconducting properties. The pentacene derivative 1 b shows ambipolar behavior using AlOx C14 PA as the gate dielectric (electron and hole mobilities of 7.6 ⋅ 10 −3 and 1.6 ⋅ 10 −1 cm 2 V −1 s −1 ), while performance of all derivatives was poor using p‐doped Silicon as the substrate. These studies highlight the importance of thin‐film formation over molecular structure. Abstract : Breaking communication : In this work functionalized anthracene‐pentacene derivatives based on substituents on the 9‐position of anthracene (H−, F−, Cl−, Br−, H3 C−) are explored. The molecules were characterized by UV‐vis spectroscopy, cyclic voltammetry, and X‐ray crystallography, as well as their performance in organic thin‐film transistors. Compound 1 b features ambipolar behavior using a SAM hybrid dielectric, while performance of all derivatives is poor using p‐doped silicon as the substrate. Film morphology emerges as the defining factor for device efficiency, overriding factors such as solid‐state packing and the HOMO‐LUMO gap.