Synthesis of tetraazatetracenes and -pentacenes: role of the substituents for their stability

Abstract

We report the synthesis of a series of novel tetraazaacene derivatives and compare their stability with respect to size, oxidation potential and position of the TIPS-ethynyl groups. The latter has the most pronounced effects on the stability. In case of azatetracenes where TIPS-alkynes are either attached laterally or in the peri-positions, the former ones dimerized while the latter are stable. Attempts to expand this concept to the corresponding tetrakis-peri-substituted heptacenes led to the isolation of the dimerized butterfly product.

2-Bromotetraazapentacene and Its Functionalization by Pd(0)-Chemistry

“…7-Bromophenazine-2,3-diol (6). In a 250 mL round-bottom flask, 4-bromophenylenediamine (5.00 g, 26.7 mmol) and 2,5dihydroxy-p-benzoquinone (4.12 g, 29.4 mmol, 1.10 equiv) were dissolved in 150 mL of ethanol.…”

“…In the following years, a number of large azaacenes were prepared by many methods, and their properties were investigated by different spectroscopic methods and by electrochemistry. − Azaacenes’ performance in organic electronic devices and their capability for singlet fission were investigated. ,− To further tune the azaacenes’ electrochemical properties, halogen atoms (F, Cl) were attached to their backbones. , Yet, with regard to potential applications as electroactive material, the parent, symmetrical bis­(triisopropyl­silyl­ethynyl)­tetra­azapenta­cene ( TIPS-TAP ) remains unchallenged in terms of stability and semiconductor performance.…”

Synthesis of 5‐Azatetracene and Comparison of Its Optical and Electrochemical Properties with Tetracene

“…Heteroacenes also have been reported to display good photoluminescence properties and high singlet fission cross‐sections, making them promising compounds for other applications [20–22] . In recent years, many azaacenes have been prepared by many methods, and their properties have been investigated by various spectroscopic methods and by electrochemistry [23–28] . The optical and electrochemical properties of N‐heteroacenes depend upon position and number of nitrogen atoms.…”

“…[20][21][22] In recent years, many azaacenes have been prepared by many methods, and their properties have been investigated by various spectroscopic methods and by electrochemistry. [23][24][25][26][27][28] The optical and electrochemical properties of N-heteroacenes depend upon position and number of nitrogen atoms. Miao and co-workers demonstrated that azaacenes containing nitrogens on internal rings exhibit lower FMO energies than their analogues with terminal heterocyclic rings.…”

Towards Nitrogen‐Rich N‐Heteropolycycles: Synthesis of Octaazaperopyrenes (OAPP)

“…To date, many azapentacenes[ 28 , 29 , 30 ] and larger acenes[ 31 , 32 , 33 ] have been synthesized which are strong electron acceptors and exhibit n ‐semiconducting behavior. [ 3 , 4 , 5 , 6 , 14 , 17 , 18 , 34 , 35 ] These studies have revealed that the position of the nitrogen atoms in the aromatic core plays an important role in influencing the semiconducting properties, electronic structure and molecular packing.…”