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.
Near‐field electrospinning (NFES) holds the potential to develop into a versatile additive nanomanufacturing platform. However, the impact of a variety of processing variables remains unresolved.Herein, the effect of solvents used to prepare suitable solutions for 3D microstructuring by electrospinning is studied. 3D straight walls of stacked fibers are fabricated using a layer‐by‐layer fiber deposition approach. The effect of the choice of substrate material is also explored. The results show that a high vapor pressure, and a low dielectric constant of the solvent, as well as a high substrate conductivity facilitate improved stacking of fiber layers. Utilizing these conditions, 3D stacked walls of polyethylene oxide are fabricated, and a maximum aspect ratio of 191.7 ± 52.6, while using a chromium/gold substrate and dichloromethane/methanol as the solvent is achieved.
This work presents the 2 nd generation of cata-annulated azaacene bisimides with increased electron affinities (up to À 4.38 eV) compared to their consaguine conventional azaacenes. These compounds were synthesized via Buchwald-Hartwig coupling followed by oxidation with MnO 2 . Crystal structure engineering through variation of the bisimide sub-stituents furnished crystalline derivatives suitable for proof of concept organic field effect transistors with electron mobilities up to 2.2 × 10 À 4 cm 2 (Vs) À 1 . Moreover, we were able to characterize the charge carrying species, the radical anion, using electron paramagnetic resonance and absorption measurements.
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