@article{RennerMahlmeisterAnhaltetal.2021, author = {Renner, Rebecca and Mahlmeister, Bernhard and Anhalt, Olga and Stolte, Matthias and W{\"u}rthner, Frank}, title = {Chiral Perylene Bisimide Dyes by Interlocked Arene Substituents in the Bay Area}, series = {Chemistry - A European Journal}, volume = {27}, journal = {Chemistry - A European Journal}, number = {46}, doi = {10.1002/chem.202101877}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249070}, pages = {11997 -- 12006}, year = {2021}, abstract = {A series of perylene bisimide (PBI) dyes bearing various aryl substituents in 1,6,7,12 bay positions has been synthesized by Suzuki cross-coupling reaction. These molecules exhibit an exceptionally large and conformationally fixed twist angle of the PBI π-core due to the high steric congestion imparted by the aryl substituents in bay positions. Single crystal X-ray analyses of phenyl-, naphthyl- and pyrenyl-functionalized PBIs reveal interlocked π-π-stacking motifs, leading to conformational chirality and the possibility for the isolation of enantiopure atropoisomers by semipreparative HPLC. The interlocked arrangement endows these molecules with substantial racemization barriers of about 120 kJ mol\(^{-1}\) for the tetraphenyl- and tetra-2-naphthyl-substituted derivatives, which is among the highest racemization barriers for axially chiral PBIs. Variable temperature NMR studies reveal the presence of a multitude of up to fourteen conformational isomers in solution that are interconverted via smaller activation barriers of about 65 kJ mol\(^{-1}\). The redox and optical properties of these core-twisted PBIs have been characterized by cyclic voltammetry, UV/Vis/NIR and fluorescence spectroscopy and their respective atropo-enantiomers were further characterized by circular dichroism (CD) and circular polarized luminescence (CPL) spectroscopy.}, language = {en} } @article{MenekseRennerMahlmeisteretal.2020, author = {Menekse, Kaan and Renner, Rebecca and Mahlmeister, Bernhard and Stolte, Matthias and W{\"u}rthner, Frank}, title = {Bowl-shaped naphthalimide-annulated corannulene as nonfullerene acceptor in organic solar cells}, series = {Organic Materials}, volume = {2}, journal = {Organic Materials}, number = {3}, issn = {2625-1825}, doi = {10.1055/s-0040-1714283}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299095}, pages = {229-234}, year = {2020}, abstract = {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.}, language = {en} }