Synthesis and Properties of New N‐Heteroheptacenes for Solution‐Based Organic Field Effect Transistors

Abstract

A series of N-heteroheptacenes was synthesized from ortho-thiophene-substituted aryl azides using a Rh -catalyzed C-H bond amination reaction to construct the thienoindole moieties. This reaction tolerated the presence of electron-donating or withdrawing groups on the aryl azide without adversely affecting the yield of the amination reaction. The central thiophene ring was created from two thienoindole pieces through a Pd-catalyzed Stille reaction to install the thioether followed by a Cu-mediated Ullman reaction to trigger the cyclization. The photophysical and electrochemical properties of the resulting focused library of N-heteroheptacenes revealed that the electronic nature is controlled by the arene substituent while single crystals grown reveal that the packing motif is influenced by the N-substituent. Solution-processed thin-film OFET devices were fabricated with the N-heteroheptacenes, and one exhibited a hole-mobility of 0.02 cm V s .

Exploration of Syntheses and Functions of Higher Ladder-type π-Conjugated Heteroacenes

“…Driver and coworkers synthesized a series of N,S-heteroheptacenes (compound 4 in Scheme 2) from ortho-thiophenesubstituted aryl azides and using Rh-catalyzed C-H bond amination reaction to obtain thienoindole moieties. 34 The two thienoindole moieties were then coupled The intramolecular electrophilic addition of an acid-activated methyl sulfinyl group to an adjacent aromatic ring is a very useful annulation process for the synthesis of ladder molecules. Mü llen utilized this process toward several S-bridged LHAs (Scheme 3).…”

“…This device showed impressive hole mobilities up to 0.5 cm 2 /V s. 50 The solution-processed thin-film method is the most convenient approach to prepare organic thin-film transistors. 80,81 N-heteroheptacene (4c) 34 with linear side chains was recently used as an active material in top-gate OFET devices and showed hole mobilities around 0.02 cm 2 /V s. PDI-based 13-ring compound (37c) 57 has also been used to prepare an OFET device. This device showed a relatively low mobility of around 8 However, the exploration of ladder molecules for application as organic electronic materials is still in its infancy.…”

Medaillen der Società Chimica Italiana für 2017

“…Zu seinen Forschungsinteressen zählen (gedruckte) organische Elektronikbauteile, organische Photovoltaikzellen und Materialien für Mehrphotonensysteme sowie Kontrastmittel für die MRI‐Bildgebung. Er ist Coautor einer Veröffentlichung in Chemistry—A European Journal über lösungsbasierte organische Feldeffekttransistoren …”

An Effective Route to Dithieno[3,2-b:2′,3′-d]thiophene-Based Hexaheteroacenes

“…Over the past two decades a large number of thiophene-based photo-and electroactive compounds has been developed and utilized to fabricate photonic and electronic devices. 1,2 In this context, dithieno[3,2-b:2',3'-d]thiophene (DTT), due to rigid planar scaffold structure with high π-conjugation as well as ability to create effective intermolecular S…S interactions, has found a wide application in the design of p-type semiconductors, including (hetero)aryl-linked DTT molecules [3][4][5][6][7][8][9][10][11] as well as ringfused molecules with DTT core, [12][13][14][15][16][17][18] for organic field-effect transistors (OFET). In addition, DTT subunit has been also used for the construction of light-harvesting materials for organic photovoltaics, [19][20][21][22][23][24][25][26][27] electrochromic [28][29][30][31] and photochromic [32][33][34] materials.…”