TY - JOUR A1 - Menekse, Kaan A1 - Renner, Rebecca A1 - Mahlmeister, Bernhard A1 - Stolte, Matthias A1 - Würthner, Frank T1 - Bowl-shaped naphthalimide-annulated corannulene as nonfullerene acceptor in organic solar cells JF - Organic Materials N2 - An electron-poor bowl-shaped naphthalimide-annulated corannulene with branched alkyl residues in the imide position was synthesized by a palladium-catalyzed cross-coupling annulation sequence. This dipolar compound exhibits strong absorption in the visible range along with a low-lying LUMO level at –3.85 eV, enabling n-type charge transport in organic thin-film transistors. Furthermore, we processed inverted bulk-heterojunction solar cells in combination with the two donor polymers PCE–10 and PM6 to achieve open-circuit voltages up to 1.04 V. By using a blend of the self-assembled naphthalimide-annulated corannulene and PCE–10, we were able to obtain a power conversion efficiency of up to 2.1%, which is to the best of our knowledge the highest reported value for a corannulene-based organic solar cell to date. KW - Chemie KW - corannulene KW - nonfullerene acceptors KW - curved π-systems KW - bulk-heterojunction solar cells KW - aggregation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299095 UR - https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0040-1714283 SN - 2625-1825 VL - 2 IS - 3 ER - TY - JOUR A1 - Schneider-Schaulies, Sibylle A1 - Schumacher, Fabian A1 - Wigger, Dominik A1 - Schöl, Marie A1 - Waghmare, Trushnal A1 - Schlegel, Jan A1 - Seibel, Jürgen A1 - Kleuser, Burkhard T1 - Sphingolipids: effectors and Achilles heals in viral infections? JF - Cells N2 - As viruses are obligatory intracellular parasites, any step during their life cycle strictly depends on successful interaction with their particular host cells. In particular, their interaction with cellular membranes is of crucial importance for most steps in the viral replication cycle. Such interactions are initiated by uptake of viral particles and subsequent trafficking to intracellular compartments to access their replication compartments which provide a spatially confined environment concentrating viral and cellular components, and subsequently, employ cellular membranes for assembly and exit of viral progeny. The ability of viruses to actively modulate lipid composition such as sphingolipids (SLs) is essential for successful completion of the viral life cycle. In addition to their structural and biophysical properties of cellular membranes, some sphingolipid (SL) species are bioactive and as such, take part in cellular signaling processes involved in regulating viral replication. It is especially due to the progress made in tools to study accumulation and dynamics of SLs, which visualize their compartmentalization and identify interaction partners at a cellular level, as well as the availability of genetic knockout systems, that the role of particular SL species in the viral replication process can be analyzed and, most importantly, be explored as targets for therapeutic intervention. KW - glycosphingolipids KW - ceramides KW - sphingosine 1-phosphate KW - sphingomyelinase KW - HIV KW - SARS-CoV-2 KW - measles Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-245151 SN - 2073-4409 VL - 10 IS - 9 ER - TY - JOUR A1 - Hofmann, Julian A1 - Fayez, Shaimaa A1 - Scheiner, Matthias A1 - Hoffmann, Matthias A1 - Oerter, Sabrina A1 - Appelt‐Menzel, Antje A1 - Maher, Pamela A1 - Maurice, Tangui A1 - Bringmann, Gerhard A1 - Decker, Michael T1 - Sterubin: Enantioresolution and Configurational Stability, Enantiomeric Purity in Nature, and Neuroprotective Activity in Vitro and in Vivo JF - Chemistry – A European Journal N2 - Alzheimer′s disease (AD) is a neurological disorder with still no preventive or curative treatment. Flavonoids are phytochemicals with potential therapeutic value. Previous studies described the flavanone sterubin isolated from the Californian plant Eriodictyon californicum as a potent neuroprotectant in several in vitro assays. Herein, the resolution of synthetic racemic sterubin (1) into its two enantiomers, (R)‐1 and (S)‐1, is described, which has been performed on a chiral chromatographic phase, and their stereochemical assignment online by HPLC‐ECD coupling. (R)‐1 and (S)‐1 showed comparable neuroprotection in vitro with no significant differences. While the pure stereoisomers were configurationally stable in methanol, fast racemization was observed in the presence of culture medium. We also established the occurrence of extracted sterubin as its pure (S)‐enantiomer. Moreover, the activity of sterubin (1) was investigated for the first time in vivo, in an AD mouse model. Sterubin (1) showed a significant positive impact on short‐ and long‐term memory at low dosages. KW - Alzheimer′s disease KW - chiral resolution KW - circular dichroism KW - Eriodictyon californicum KW - flavonoids KW - sterubin Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215993 VL - 26 IS - 32 SP - 7299 EP - 7308 ER - TY - JOUR A1 - Kim, Jin Hong A1 - Liess, Andreas A1 - Stolte, Matthias A1 - Krause, Ana-Maria A1 - Stepanenko, Vladimir A1 - Zhong, Chuwei A1 - Bialas, David A1 - Spano, Frank A1 - Würthner, Frank T1 - An Efficient Narrowband Near-Infrared at 1040 nm Organic Photodetector Realized by Intermolecular Charge Transfer Mediated Coupling Based on a Squaraine Dye JF - Advanced Materials N2 - A highly sensitive short-wave infrared (SWIR, λ > 1000 nm) organic photodiode (OPD) is described based on a well-organized nanocrystalline bulk-heterojunction (BHJ) active layer composed of a dicyanovinyl-functionalized squaraine dye (SQ-H) donor material in combination with PC\(_{61}\)BM. Through thermal annealing, dipolar SQ-H chromophores self-assemble in a nanoscale structure with intermolecular charge transfer mediated coupling, resulting in a redshifted and narrow absorption band at 1040 nm as well as enhanced charge carrier mobility. The optimized OPD exhibits an external quantum efficiency (EQE) of 12.3% and a full-width at half-maximum of only 85 nm (815 cm\(^{-1}\)) at 1050 nm under 0 V, which is the first efficient SWIR OPD based on J-type aggregates. Photoplethysmography application for heart-rate monitoring is successfully demonstrated on flexible substrates without applying reverse bias, indicating the potential of OPDs based on short-range coupled dye aggregates for low-power operating wearable applications. KW - squaraine dyes KW - crystal engineering KW - J-aggregates KW - near-infrared sensitivity KW - organic photodiodes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256374 VL - 33 IS - 26 ER - TY - JOUR A1 - Lehmann, Matthias A1 - Dechant, Moritz A1 - Weh, Dominik A1 - Freytag, Emely T1 - Metal Phthalocyanine−Fullerene Dyads: Promising Lamellar Columnar Donor−Acceptor Liquid Crystal Phases JF - ChemPlusChem N2 - Liquid crystal (LC) shape‐amphiphiles with a disc tethered to a fullerene have been intensely studied for the application in photovoltaics, and helical nanosegregation of C\(_{60}\) has been claimed around the π‐stacking disks based on X‐ray results. The most promising materials reported to date have been resynthesized and studied comprehensively by XRS, density measurements, modelling, and electron density reconstruction. In contrast to previous reports, the results indicate that metal phthalocyanine−fullerene mesogens pack in lamellar columnar phases with p2gm symmetry. Fullerenes assemble in layers and are flanked by phthalocyanine columns, thus explaining the balanced charge carrier mobility of electrons and holes. Such variable donor−acceptor structures are promising for organic electronic applications. KW - Donor−acceptor dyads KW - fullerenes KW - liquid crystals KW - nanosegregation KW - shape-amphiphiles Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218531 VL - 85 IS - 8 SP - 1934 EP - 1938 ER - TY - JOUR A1 - Shen, Chia-An A1 - Bialas, David A1 - Hecht, Markus A1 - Stepanenko, Vladimir A1 - Sugiyasu, Kazunori A1 - Würthner, Frank T1 - Polymorphism in squaraine dye aggregates by self-assembly pathway differentiation: panchromatic tubular dye nanorods versus J-aggregate nanosheets JF - Angewandte Chemie International Edition N2 - A bis(squaraine) dye equipped with alkyl and oligoethyleneglycol chains was synthesized by connecting two dicyanomethylene substituted squaraine dyes with a phenylene spacer unit. The aggregation behavior of this bis(squaraine) was investigated in non-polar toluene/tetrachloroethane (98:2) solvent mixture, which revealed competing cooperative self-assembly pathways into two supramolecular polymorphs with entirely different packing structures and UV/Vis/NIR absorption properties. The self-assembly pathway can be controlled by the cooling rate from a heated solution of the monomers. For both polymorphs, quasi-equilibrium conditions between monomers and the respective aggregates can be established to derive thermodynamic parameters and insights into the self-assembly mechanisms. AFM measurements revealed a nanosheet structure with a height of 2 nm for the thermodynamically more stable polymorph and a tubular nanorod structure with a helical pitch of 13 nm and a diameter of 5 nm for the kinetically favored polymorph. Together with wide angle X-ray scattering measurements, packing models were derived: the thermodynamic polymorph consists of brick-work type nanosheets that exhibit red-shifted absorption bands as typical for J-aggregates, while the nanorod polymorph consists of eight supramolecular polymer strands of the bis(squaraine) intertwined to form a chimney-type tubular structure. The absorption of this aggregate covers a large spectral range from 550 to 875 nm, which cannot be rationalized by the conventional exciton theory. By applying the Essential States Model and considering intermolecular charge transfer, the aggregate spectrum was adequately reproduced, revealing that the broad absorption spectrum is due to pronounced donor-acceptor overlap within the bis(squaraine) nanorods. The latter is also responsible for the pronounced bathochromic shift observed for the nanosheet structure as a result of the slip-stacked arranged squaraine chromophores. KW - organic chemistry KW - supramolecular polymers KW - nanorods and nanosheets KW - polymorphism KW - squaraine dyes KW - cooperative self-assembly Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256443 IS - 21 ET - 60 ER - TY - JOUR A1 - Pinzner, Florian A1 - Keller, Thorsten A1 - Mut, Jürgen A1 - Bechold, Julian A1 - Seibel, Jürgen A1 - Groll, Jürgen T1 - Polyoxazolines with a vicinally double-bioactivated terminus for biomacromolecular affinity assessment JF - Sensors N2 - Interactions between proteins and carbohydrates with larger biomacromolecules, e.g., lectins, are usually examined using self-assembled monolayers on target gold surfaces as a simplified model measuring setup. However, most of those measuring setups are either limited to a single substrate or do not allow for control over ligand distance and spacing. Here, we develop a synthetic strategy, consisting of a cascade of a thioesterification, native chemical ligation (NCL) and thiol-ene reaction, in order to create three-component polymer conjugates with a defined double bioactivation at the chain end. The target architecture is the vicinal attachment of two biomolecule residues to the α telechelic end point of a polymer and a thioether group at the ω chain end for fixating the conjugate to a gold sensor chip surface. As proof-of-principle studies for affinity measurements, we demonstrate the interaction between covalently bound mannose and ConA in surface acoustic wave (SAW) and surface plasmon resonance (SPR) experiments. KW - polyoxazolines KW - functionalization KW - lectin Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239530 SN - 1424-8220 VL - 21 IS - 9 ER - TY - JOUR A1 - Brust, Felix A1 - Nagler, Oliver A1 - Shoyama, Kazutaka A1 - Stolte, Matthias A1 - Würthner, Frank T1 - Organic Light‐Emitting Diodes Based on Silandiol‐Bay‐Bridged Perylene Bisimides JF - Advanced Optical Materials N2 - Perylene bisimides (PBIs) are among the best fluorophores but have to be enwrapped for optoelectronic applications by large and heavy substituents to prevent their ππ‐stacking, which is known to accelerate non‐radiative decay processes in the solid state. Here, light‐weight di‐tert‐butylsilyl groups are introduced to bridge 1,12‐dihydroxy and 1,6,7,12‐tetrahydroxy PBIs to afford sublimable dyes for vacuum‐processed optoelectronic devices. For both new compounds, this substitution provides a twisted and shielded perylene π‐core whose, via OSiObridges, rigid structure affords well‐resolved absorption and emission spectra with strong fluorescence in solution, as well as in the solid state. The usefulness of these dyes for vacuum‐processed optoelectronic devices is demonstrated in organic light‐emitting diodes (OLEDs) that show monomer‐like emission spectra and high maximum external quantum efficiency (EQEmax) values of up to 3.1% for the doubly silicon‐bridged PBI. KW - organic light emitting diodes KW - perylene bisimide dyes KW - rigidification KW - solid‐state emission KW - vacuum processable Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312599 VL - 11 IS - 5 ER - TY - JOUR A1 - Schmidt, David A1 - Stolte, Matthias A1 - Süß, Jasmin A1 - Liess, Dr. Andreas A1 - Stepanenko, Vladimir A1 - Würthner, Frank T1 - Protein-like enwrapped perylene bisimide chromophore as bright microcrystalline emitter material JF - Angewandte Chemie International Edition N2 - Strongly emissive solid‐state materials are mandatory components for many emerging optoelectronic technologies, but fluorescence is often quenched in the solid state owing to strong intermolecular interactions. The design of new organic pigments, which retain their optical properties despite their high tendency to crystallize, could overcome such limitations. Herein, we show a new material with monomer‐like absorption and emission profiles as well as fluorescence quantum yields over 90 % in its crystalline solid state. The material was synthesized by attaching two bulky tris(4‐tert‐butylphenyl)phenoxy substituents at the perylene bisimide bay positions. These substituents direct a packing arrangement with full enwrapping of the chromophore and unidirectional chromophore alignment within the crystal lattice to afford optical properties that resemble those of their natural pigment counterparts, in which chromophores are rigidly embedded in protein environments. KW - cristal engeneering KW - dyes KW - flourescence quantum yield KW - perylene bisimides KW - solid-state emitters Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204809 VL - 58 IS - 38 ER - TY - JOUR A1 - Griesbeck, Stefanie A1 - Michail, Evripidis A1 - Rauch, Florian A1 - Ogasawara, Hiroaki A1 - Wang, Chenguang A1 - Sato, Yoshikatsu A1 - Edkins, Robert M. A1 - Zhang, Zuolun A1 - Taki, Masayasu A1 - Lambert, Christoph A1 - Yamaguchi, Shigehiro A1 - Marder, Todd B. T1 - The Effect of Branching on One- and Two-Photon Absorption, Cell Viability and Localization of Cationic Triarylborane Chromophores with Dipolar versus Octupolar Charge Distributions for Cellular Imaging JF - Chemistry - A European Journal N2 - Two different chromophores, namely a dipolar and an octupolar system, were prepared and their linear and nonlinear optical properties as well as their bioimaging capabilities were compared. Both contain triphenylamine as the donor and a triarylborane as the acceptor, the latter modified with cationic trimethylammonio groups to provide solubility in aqueous media. The octupolar system exhibits a much higher two‐photon brightness, and also better cell viability and enhanced selectivity for lysosomes compared with the dipolar chromophore. Furthermore, both dyes were applied in two‐photon excited fluorescence (TPEF) live‐cell imaging. KW - boranes KW - cell imaging KW - fluerescence KW - lysosome KW - two-photon excited fluorescence Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204829 VL - 25 IS - 57 ER -