Low Bandgap Bistetracene‐Based Organic Semiconductors Exhibiting Air Stability, High Aromaticity and Mobility

Abstract

The benchmark of soluble organic semiconductors based on acenes is the 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN). However TIPS-PEN still suffers from photoinduced oxidation due to its low degree of aromaticity. Increasing the aromaticity while keeping similar optical and electrochemical properties as well as a shape suitable for good hole transport can be achieved with two-dimensional polycyclic aromatic hydrocarbons (2D-PAHs). Herein, we present an efficient synthesis and characterization of bistetracene derivatives that exhibit a band gap up to 1.71 eV and an increased stability up to 21 times compared to TIPS-PEN and mobility over 0.1 cm V s in solution-processed organic field-effect transistors. Based on simple structural consideration, the high stability is attributed to the aromaticity of the bistetracene which is comparable to an anthrancene along each tetracene. According to Clar's sextet rule, the bistetracene should be best regarded as two anthracenes fused at the face bridged by two ethylenic spacers. The synthesis path paves the way towards the preparation of ambipolar and/or longer 2D-PAHs such as bispentacenes and could give rise to organic semiconductors with interesting properties.

Dehydrative π-extension to nanographenes with zig-zag edges

“…Structure analysis of highly insoluble pristine NGs is evolving as major problem in modern nanographene sciences. Therefore, solubilizing groups are typically attached to the PAH’s skeleton, leading inevitably to an alteration of its original characteristics 28 – 30 , 32 . Spectroscopically at the border of solubility for NMR analysis, we elucidated the 1 H NMR spectrum of DBATT , obtained at 100 °C in o -DCB (Fig.…”

“…Keywords that highlight acene-type PAHs with zig-zag periphery range from singlet fission 17 – 21 , auspicious charge carrier mobilities 22 , 23 , to amplified spontaneous emission 24 , and enlarge the interest in PAHs by the fields of spintronics and molecular magnetism 25 - 27 . Recently, various research groups reported on substituted angularly fused-tetracenes 28 – 32 , which overcome the low stability of linear acenes, by increasing the intrinsic number of Clar’s-sextets 33 . These fused structures showed excellent performances in field-effect transistors 28 , 29 , 31 , 32 .…”

“…Recently, various research groups reported on substituted angularly fused-tetracenes 28 – 32 , which overcome the low stability of linear acenes, by increasing the intrinsic number of Clar’s-sextets 33 . These fused structures showed excellent performances in field-effect transistors 28 , 29 , 31 , 32 . Among these slipped bis-tetracenes, a significant focus was set on derivatives of the 2.3,8.9-dibenzanthanthrene ( DBATT ) aromatic carbon skeleton.…”

Stable 2D Bisthienoacenes: Synthesis, Crystal Packing, and Photophysical Properties

“…It's amazing that both 2D thienoacenes exhibited exceptionally high photostability with a half‐life time ( t 1/2 ) of 226 days for BTT‐4TIPS and 129 days for BTP‐4TIPS under air (Table S2, Figure ). Taking the simple structural consideration, the high stability might be attributed to the aromaticity of the bisthienoacene, which is comparable to an anthrancene along each thienoacene . The excited‐state properties of BTT‐4TIPS and BTP‐4TIPS were further investigated using the fs and ns transient absorption (TA) spectroscopy.…”

O‐Doped Nanographenes: A Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed‐Valence Complexes

“…Inspired by the chemical structures of natural anthocyanins and artificial π‐expanded xanthenium cations, we inferred that pyranyl and pyrylium rings could be used to prepare the O‐doped derivatives of PAHs 1 C – 3 C and to engineer p ‐type organic semiconductors. Out of the three PAHs 1 C – 3 C (Figure , top), attention has been paid only to dibenzanthanthrene ( 1 C ) and its derivatives, with applications in single‐molecule transistors, optical interaction with alkali atoms for quantum memory, as a single emitter for super‐resolution microscopy, and semiconductors with high mobility in solution‐processed OFETs …”