Cata‐Annulated Azaacene Bisimides

Abstract

Ultra‐electron‐deficient azaacenes were synthesized via Buchwald‐Hartwig coupling of ortho‐diaminoarenes with chlorinated mellophanic diimide followed by oxidation of the intermediate N,N’‐dihydro compounds with MnO2 or PbO2. The resulting cata‐annulated bisimide azaacenes have ultrahigh electron affinities with first reduction potentials as low as −0.35 V recorded for a tetraazapentacene. Attempts to prepare a tetrakis(dicarboximide)tetraazaheptacene resulted in the formation of a symmetric butterfly dimer.

Second Generation of Cata‐Annulated Azaacene Bisimides: Towards Electron‐Accepting Materials

“…For naphthalene and anthracene diamines 2 and 3, Pd 2 (dba) 3 /RuPhos or RuPhos Pd G1 was employed as catalyst and Cs 2 CO 3 as base. [20,23] The reactions were performed in toluene and furnished compound 5-H 2 and 6-H 2 in 47 %-77 % yields. Similar to our previous report, the phenazine diamine 4 was coupled in Hünig's base leading to 7-H 2 in 34 %-50 % yields.…”

“…Previously, we reported a novel synthetic access to cata‐annulated azaacene bisimides with ultrahigh electron affinities [20] . However, due to the flexible hexyl substituents at the bisimide nitrogens, these compounds crystallized poorly and were thus ill‐suited for OFETs as they did not form continuous films.…”

“…[19] Previously, we reported a novel synthetic access to cataannulated azaacene bisimides with ultrahigh electron affinities. [20] However, due to the flexible hexyl substituents at the bisimide nitrogens, these compounds crystallized poorly and were thus ill-suited for OFETs as they did not form continuous films. In this contribution, we demonstrate that varying the imide substituents between phenyl, benzyl, and phenethyl improves the azaacene-bisimide hybrids' crystallization behavior while retaining the electron-deficient character of the azaacene cores.…”

Recent progress in pyrazinacenes containing nonbenzenoid rings: synthesis, properties and applications

“…Besides, N-containing heterocycles including carbazole, 60 imidazole, 100–102 indolizine, 103 etc. 65,68,104–106 are more popular decorating units for azaacenes. For example, Liao et al 60 synthesized a series of stable and soluble carbazole-containing azaacenes ( 65a-c ) via sample condensation reactions.…”

Improved Syntheses of Halogenated Benzene-1,2,3,4-Tetracarboxylic Diimides

“…Although MDI is slightly less electron accepting than PMDI, , its geometry enables synthetic possibilities unavailable to the sterically constrained PMDI core. Core dichlorinated N , N ′-dihexyl MDI ( Cl 2 -MDI-Hex ), for example, readily undergoes both S N Ar and Pd-catalyzed substitutions with aromatic ortho dinucleophiles to lead to a range of highly chromophoric and electron-accepting hetero- and azaacene structures. , The development of MDI as a building block is further attractive because it is derived from 1,2,3,4-tetramethylbenzene, which is a byproduct of durene synthesis and a constituent of petroleum extract that has no significant industrial use . With these observations in mind, we set out to establish generalizable synthetic methods for obtaining differently halogenated MDI derivatives.…”