Filters

2020 - 20213

More filters

2021 - 20223
Reset filters

Settings

Author: Komber, Hartmut × Publisher: Weinheim : Wiley-VCH ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Persistent peri-Heptacene: Synthesis and In Situ Characterization
    (Weinheim : Wiley-VCH, 2021) Ajayakumar, M.R.; Ma, Ji; Lucotti, Andrea; Schellhammer, Karl Sebastian; Serra, Gianluca; Dmitrieva, Evgenia; Rosenkranz, Marco; Komber, Hartmut; Liu, Junzhi; Ortmann, Frank; Tommasini, Matteo; Feng, Xinliang
    n-peri-Acenes (n-PAs) have gained interest as model systems of zigzag-edged graphene nanoribbons for potential applications in nanoelectronics and spintronics. However, the synthesis of n-PAs larger than peri-tetracene remains challenging because of their intrinsic open-shell character and high reactivity. Presented here is the synthesis of a hitherto unknown n-PA, that is, peri-heptacene (7-PA), in which the reactive zigzag edges are kinetically protected with eight 4-tBu-C6H4 groups. The formation of 7-PA is validated by high-resolution mass spectrometry and in situ FT-Raman spectroscopy. 7-PA displays a narrow optical energy gap of 1.01 eV and exhibits persistent stability (t1/2≈25 min) under inert conditions. Moreover, electron-spin resonance measurements and theoretical studies reveal that 7-PA exhibits an open-shell feature and a significant tetraradical character. This strategy could be considered a modular approach for the construction of next-generation (3 N+1)-PAs (where N≥3). © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH
  • Thumbnail Image
    Item
    Tailoring Magnetic Features in Zigzag-Edged Nanographenes by Controlled Diels–Alder Reactions
    (Weinheim : Wiley-VCH, 2020) Ajayakumar, M.R.; Fu, Yubin; Liu, Fupin; Komber, Hartmut; Tkachova, Valeriya; Xu, Chi; Zhou, Shengqiang; Popov, Alexey A.; Liu, Junzhi; Feng, Xinliang
    Nanographenes (NGs) with tunable electronic and magnetic properties have attracted enormous attention in the realm of carbon-based nanoelectronics. In particular, NGs with biradical character at the ground state are promising building units for molecular spintronics. However, most of the biradicaloids are susceptible to oxidation under ambient conditions and photolytic degradation, which hamper their further applications. Herein, we demonstrated the feasibility of tuning the magnetic properties of zigzag-edged NGs in order to enhance their stability via the controlled Diels–Alder reactions of peri-tetracene (4-PA). The unstable 4-PA (y0=0.72; half-life, t1/2=3 h) was transformed into the unprecedented benzo-peri-tetracenes (BPTs) by a one-side Diels–Alder reaction, which featured a biradical character at the ground state (y0=0.60) and exhibited remarkable stability under ambient conditions for several months. In addition, the fully zigzag-edged circumanthracenes (CAs) were achieved by two-fold or stepwise Diels–Alder reactions of 4-PA, in which the magnetic properties could be controlled by employing the corresponding dienophiles. Our work reported herein opens avenues for the synthesis of novel zigzag-edged NGs with tailor-made magnetic properties. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
  • Thumbnail Image
    Item
    Ultrasoft and High-Mobility Block Copolymers for Skin-Compatible Electronics
    (Weinheim : Wiley-VCH, 2020) Ditte, Kristina; Perez, Jonathan; Chae, Soosang; Hambsch, Mike; Al-Hussein, Mahmoud; Komber, Hartmut; Formanek, Peter; Mannsfeld, Stefan C.B.; Fery, Andreas; Kiriy, Anton; Lissel, Franziska
    Polymer semiconductors (PSCs) are an essential component of organic field-effect transistors (OFETs), but their potential for stretchable electronics is limited by their brittleness and failure susceptibility upon strain. Herein, a covalent connection of two state-of-the-art polymers—semiconducting poly-diketo-pyrrolopyrrole-thienothiophene (PDPP-TT) and elastomeric poly(dimethylsiloxane) (PDMS)—in a single triblock copolymer (TBC) chain is reported, which enables high charge carrier mobility and low modulus in one system. Three TBCs containing up to 65 wt% PDMS were obtained, and the TBC with 65 wt% PDMS content exhibits mobilities up to 0.1 cm2 V−1 s−1, in the range of the fully conjugated reference polymer PDPP-TT (0.7 cm2 V−1 s−1). The TBC is ultrasoft with a low elastic modulus (5 MPa) in the range of mammalian tissue. The TBC exhibits an excellent stretchability and extraordinary durability, fully maintaining the initial electric conductivity in a doped state after 1500 cycles to 50% strain. © 2020 The Authors. Advanced Materials published by Wiley-VCH GmbH