@article{BoldStolteShoyamaetal.2022,
  author    = {Bold, Kevin and Stolte, Matthias and Shoyama, Kazutaka and Krause, Ana-Maria and Schmiedel, Alexander and Holzapfel, Marco and Lambert, Christoph and W{\"u}rthner, Frank},
  title     = {Macrocyclic Donor-Acceptor Dyads Composed of Oligothiophene Half-Cycles and Perylene Bisimides},
  series = {Chemistry - A European Journal},
  volume    = {28},
  journal   = {Chemistry - A European Journal},
  number    = {30},
  doi       = {10.1002/chem.202200355},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276435},
  year      = {2022},
  abstract  = {A series of donor-acceptor (D-A) macrocyclic dyads consisting of an electron-poor perylene bisimide (PBI) π-scaffold bridged with electron-rich α-oligothiophenes bearing four, five, six and seven thiophene units between the two phenyl-imide substituents has been synthesized and characterized by steady-state UV/Vis absorption and fluorescence spectroscopy, cyclic and differential pulse voltammetry as well as transient absorption spectroscopy. Tying the oligothiophene strands in a conformationally fixed macrocyclic arrangement leads to a more rigid π-scaffold with vibronic fine structure in the respective absorption spectra. Electrochemical analysis disclosed charged state properties in solution which are strongly dependent on the degree of rigidification within the individual macrocycle. Investigation of the excited state dynamics revealed an oligothiophene bridge size-dependent fast charge transfer process for the macrocyclic dyads upon PBI subunit excitation.},
  language  = {en}
}
@article{FullPanchalGoetzetal.2021,
  author    = {Full, Julian and Panchal, Santosh P. and G{\"o}tz, Julian and Krause, Ana-Maria and Nowak-Kr{\´o}l, Agnieszka},
  title     = {Modulare Synthese helikal-chiraler Organobor-Verbindungen: Ausschnitte verl{\"a}ngerter Helices},
  series = {Angewandte Chemie},
  volume    = {133},
  journal   = {Angewandte Chemie},
  number    = {8},
  doi       = {10.1002/ange.202014138},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224385},
  pages     = {4396 -- 4403},
  year      = {2021},
  abstract  = {Zwei Arten helikal-chiraler Verbindungen mit einem oder zwei Boratomen wurden nach einem modularen Ansatz synthetisiert. Die Bildung der helikalen Strukturen erfolgte durch Einf{\"u}hrung von Bor in flexible Biaryl- bzw. Triaryl-Vorstufen, hergestellt aus kleinen achiralen Bausteinen. Die durchgehend ortho-fusionierten Azabora[7]helicene zeichnen sich dabei durch außergew{\"o}hnliche Konfigurationsstabilit{\"a}t, blaue oder gr{\"u}ne Fluoreszenz in L{\"o}sung mit Quantenausbeuten (Φ\(_{fl}\)) von 18-24 \%, gr{\"u}ne oder gelbe Emission im Festk{\"o}rper (Φ\(_{fl}\) bis zu 23 \%) und starke chiroptische Resonanz mit großen Anisotropiefaktoren von bis zu 1.12×10\(^{-2}\) aus. Azabora[9]helicene, aufgebaut aus winkelf{\"o}rmig sowie linear angeordneten Ringen, sind blaue Emitter mit Φ\(_{fl}\) von bis zu 47 \% in CH\(_{2}\)Cl\(_{2}\) und 25 \% im Festk{\"o}rper. DFT-Rechnungen zeigen, dass ihre P-M-Interkonversion {\"u}ber einen komplexeren Weg verl{\"a}uft als im Fall von H1. R{\"o}ntgenstrukturanalyse von Einkristallen zeigt deutliche Unterschiede in der Packungsanordnung von Methyl- und Phenylderivaten auf. Die Molek{\"u}le werden als Prim{\"a}rstrukturen verl{\"a}ngerter Helices vorgeschlagen.},
  language  = {de}
}
@article{WehRueheHerbertetal.2021,
  author    = {Weh, Manuel and R{\"u}he, Jessica and Herbert, Benedikt and Krause, Ana-Maria and W{\"u}rthner, Frank},
  title     = {Deracemization of Carbohelicenes by a Chiral Perylene Bisimide Cyclophane Template Catalyst},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {28},
  doi       = {10.1002/anie.202104591},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244787},
  pages     = {15323 -- 15327},
  year      = {2021},
  abstract  = {Deracemization describes the conversion of a racemic mixture of a chiral molecule into an enantioenriched mixture or an enantiopure compound without structural modifications. Herein, we report an inherently chiral perylene bisimide (PBI) cyclophane whose chiral pocket is capable of transforming a racemic mixture of [5]-helicene into an enantioenriched mixture with an enantiomeric excess of 66 \%. UV/Vis and fluorescence titration studies reveal this cyclophane host composed of two helically twisted PBI dyes has high binding affinities for the respective homochiral carbohelicene guests, with outstanding binding constants of up to 3.9×10\(^{10}\) m\(^{-1}\) for [4]-helicene. 2D NMR studies and single-crystal X-ray analysis demonstrate that the observed strong and enantioselective binding of homochiral carbohelicenes and the successful template-catalyzed deracemization of [5]-helicene can be explained by the enzyme-like perfect shape complementarity of the macrocyclic supramolecular host.},
  language  = {en}
}
@article{FullPanchalGoetzetal.2021,
  author    = {Full, Julian and Panchal, Santosh P. and G{\"o}tz, Julian and Krause, Ana-Maria and Nowak-Kr{\´o}l, Agnieszka},
  title     = {Modular Synthesis of Organoboron Helically Chiral Compounds: Cutouts from Extended Helices},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {8},
  doi       = {10.1002/anie.202014138},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225775},
  pages     = {4350 -- 4357},
  year      = {2021},
  abstract  = {Two types of helically chiral compounds bearing one and two boron atoms were synthesized by a modular approach. Formation of the helical scaffolds was executed by the introduction of boron to flexible biaryl and triaryl derived from small achiral building blocks. All-ortho-fused azabora[7]helicenes feature exceptional configurational stability, blue or green fluorescence with quantum yields (Φ\(_{fl}\)) of 18-24 \% in solution, green or yellow solid-state emission (Φ\(_{fl}\) up to 23 \%), and strong chiroptical response with large dissymmetry factors of up to 1.12×10\(^{-2}\). Azabora[9]helicenes consisting of angularly and linearly fused rings are blue emitters exhibiting Φ\(_{fl}\) of up to 47 \% in CH\(_{2}\)Cl\(_{2}\) and 25 \% in the solid state. As revealed by the DFT calculations, their P-M interconversion pathway is more complex than that of H1. Single-crystal X-ray analysis shows clear differences in the packing arrangement of methyl and phenyl derivatives. These molecules are proposed as primary structures of extended helices.},
  language  = {en}
}
@article{MahlShoyamaKrauseetal.2020,
  author    = {Mahl, Magnus and Shoyama, Kazutaka and Krause, Ana-Maria and Schmidt, David and W{\"u}rthner, Frank},
  title     = {Base-Assisted Imidization: A Synthetic Method for the Introduction of Bulky Imide Substituents to Control Packing and Optical Properties of Naphthalene and Perylene Imides},
  series = {Angewandte Chemie International Edition},
  volume    = {59},
  journal   = {Angewandte Chemie International Edition},
  number    = {32},
  doi       = {10.1002/anie.202004965},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218246},
  pages     = {13401 -- 13405},
  year      = {2020},
  abstract  = {We report the direct imidization of naphthalene and perylene dicarboxylic anhydrides/esters with bulky ortho,ortho-diaryl- and ortho,ortho-dialkynylaniline derivatives. This imidization method uses n-butyllithium as a strong base to increase the reactivity of bulky amine derivatives, proceeds under mild reaction conditions, requires only stoichiometric amounts of reactants and gives straightforward access to new sterically crowded rylene dicarboximides. Mechanistic investigations suggest an isoimide as intermediary product, which was converted to the corresponding imide upon addition of an aqueous base. Single-crystal X-ray diffraction analyses reveal dimeric packing motifs for monoimides, while two-side shielded bisimides crystallize in isolated molecules without close π-π-interactions. Spectroscopic investigations disclose the influence of the bulky substituents on the optical properties in the solid state.},
  language  = {en}
}