Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-19870 Wissenschaftlicher Artikel Hoche, Joscha; Schulz, Alexander; Dietrich, Lysanne Monika; Humeniuk, Alexander; Stolte, Matthias; Schmidt, David; Brixner, Tobias; Würthner, Frank; Mitric, Roland The origin of the solvent dependence of fluorescence quantum yields in dipolar merocyanine dyes Fluorophores with high quantum yields are desired for a variety of applications. Optimization of promising chromophores requires an understanding of the non-radiative decay channels that compete with the emission of photons. We synthesized a new derivative of the famous laser dye 4-dicyanomethylen-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM),i.e., merocyanine 4-(dicyanomethylene)-2-tert-butyl-6-[3-(3-butyl-benzothiazol-2-ylidene)1-propenyl]-4H-pyran (DCBT). We measured fluorescence lifetimes and quantum yields in a variety of solvents and found a trend opposite to the energy gap law.This motivated a theoretical investigation into the possible non-radiative decay channels. We propose that a barrier to a conical intersection exists that is very sensitive to the solvent polarity. The conical intersection is characterized by a twisted geometry which allows a subsequent photoisomerization. Transient absorption measurements confirmed the formation of a photoisomer in unpolar solvents, while the measurements of fluorescence quantum yields at low temperature demonstrated the existence of an activation energy barrier. 2019 11013 Chemical Science 10 urn:nbn:de:bvb:20-opus-198707 Institut für Physikalische und Theoretische Chemie OPUS4-18039 unpublished Stennett, Tom E.; Bissinger, Philipp; Griesbeck, Stefanie; Ullrich, Stefan; Krummenacher, Ivo; Auth, Michael; Sperlich, Andreas; Stolte, Matthias; Radacki, Krzysztof; Yao, Chang-Jiang; Würthner, Frank; Steffen, Andreas; Marder, Todd B.; Braunschweig, Holger Near-Infrared Quadrupolar Chromophores Combining Three-Coordinate Boron-Based Superdonor and Superacceptor Units In this work, two new quadrupolar A-π-D-π-A chromophores have been prepared featuring a strongly electron- donating diborene core and strongly electron-accepting dimesitylboryl F(BMes2) and bis(2,4,6-tris(trifluoromethyl)phenyl)boryl (BMes2) end groups. Analysis of the compounds by NMR spectroscopy, X-ray crystallography, cyclic voltammetry and UV-vis-NIR absorption and emission spectroscopy indicated that the compounds possess extended conjugated π-systems spanning their B4C8 cores. The combination of exceptionally potent π-donor (diborene) and π- acceptor (diarylboryl) groups, both based on trigonal boron, leads to very small HOMO-LUMO gaps, resulting in strong absorption in the near-IR region with maxima in THF at 840 and 1092 nm, respectively, and very high extinction coefficients of ca. 120,000 M-1cm-1. Both molecules also display weak near-IR fluorescence with small Stokes shifts. 2019 Angewandte Chemie, International Edition urn:nbn:de:bvb:20-opus-180391 10.1002/anie.201900889 Physikalisches Institut OPUS4-22458 Wissenschaftlicher Artikel Hecht, Markus; Leowanawat, Pawaret; Gerlach, Tabea; Stepanenko, Vladimir; Stolte, Matthias; Lehmann, Matthias; Würthner, Frank Self-Sorting Supramolecular Polymerization: Helical and Lamellar Aggregates of Tetra-Bay-Acyloxy Perylene Bisimide A new perylene bisimide (PBI), with a fluorescence quantum yield up to unity, self-assembles into two polymorphic supramolecular polymers. This PBI bears four solubilizing acyloxy substituents at the bay positions and is unsubstituted at the imide position, thereby allowing hydrogen-bond-directed self-assembly in nonpolar solvents. The formation of the polymorphs is controlled by the cooling rate of hot monomer solutions. They show distinctive absorption profiles and morphologies and can be isolated in different polymorphic liquid-crystalline states. The interchromophoric arrangement causing the spectral features was elucidated, revealing the formation of columnar and lamellar phases, which are formed by either homo- or heterochiral self-assembly, respectively, of the atropoenantiomeric PBIs. Kinetic studies reveal a narcissistic self-sorting process upon fast cooling, and that the transformation into the heterochiral (racemic) sheetlike self-assemblies proceeds by dissociation via the monomeric state. 2020 6 Angewandte Chemie International Edition 59 39 17084 17090 urn:nbn:de:bvb:20-opus-224586 10.1002/anie.202006744 Institut für Organische Chemie OPUS4-14925 Wissenschaftlicher Artikel He, Tao; Stolte, Matthias; Burschka, Christian; Hansen, Nis Hauke; Musiol, Thomas; Kälblein, Daniel; Pflaum, Jens; Tao, Xutang; Brill, Jochen; Würthner, Frank Single-crystal field-effect transistors of new Cl\(_{2}\)-NDI polymorph processed by sublimation in air Physical properties of active materials built up from small molecules are dictated by their molecular packing in the solid state. Here we demonstrate for the first time the growth of n-channel single-crystal field-effect transistors and organic thin-film transistors by sublimation of 2,6-dichloro-naphthalene diimide in air. Under these conditions, a new polymorph with two-dimensional brick-wall packing mode (\(\beta\)-phase) is obtained that is distinguished from the previously reported herringbone packing motif obtained from solution (\(\alpha\)-phase). We are able to fabricate single-crystal field-effect transistors with electron mobilities in air of up to 8.6 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\) (\(\alpha\)-phase) and up to 3.5 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\) (\(\beta\)-phase) on n-octadecyltriethoxysilane-modified substrates. On silicon dioxide, thin-film devices based on \(\beta\)-phase can be manufactured in air giving rise to electron mobilities of 0.37 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\). The simple crystal and thin-film growth procedures by sublimation under ambient conditions avoid elaborate substrate modifications and costly vacuum equipment-based fabrication steps. 2015 Nature Communications 6 5954 urn:nbn:de:bvb:20-opus-149255 10.1038/ncomms6954 Physikalisches Institut OPUS4-28721 Wissenschaftlicher Artikel Müller, Ulrich; Spenst, Peter; Kagerer, Philipp; Stolte, Matthias; Würthner, Frank; Pflaum, Jens Photon-Correlation Studies on Multichromophore Macrocycles of Perylene Dyes Organic dyes offer unique properties for their application as room temperature single photon emitters. By means of photon-correlation, the emission characteristics of macrocyclic para-xylylene linked perylene bisimide (PBI) trimers and tetramers dispersed in polymethyl methacrylate matrices are analyzed. The optical data indicate that, despite of the strong emission enhancement of PBI trimers and tetramers according to their larger number of chromophores, the photon-correlation statistics still obeys that of single photon emitters. Moreover, driving PBI trimers and tetramers at higher excitation powers, saturated emission behavior for monomers is found while macrocycle emission is still far-off saturation but shows enhanced fluctuations. This observation is attributed to fast singlet-singlet annihilation, i.e., faster than the radiative lifetime of the excited S1 state, and the enlarged number of conformational arrangements of multichromophores in the polymeric host. Finally, embedding trimeric PBI macrocycles in active organic light-emitting diode matrices, electrically driven bright fluorescence together with an indication for antibunching at room temperature can be detected. This, so far, has only been observed for phosphorescent emitters that feature much longer lifetimes of the excited states and, thus, smaller radiative recombination rates. The results are discussed in the context of possible effects on the g(2) behavior of molecular emitters. 2022 Advanced Optical Materials 10 14 urn:nbn:de:bvb:20-opus-287219 10.1002/adom.202200234 Physikalisches Institut OPUS4-27653 Wissenschaftlicher Artikel Kim, Jin Hong; Schembri, Tim; Bialas, David; Stolte, Matthias; Würthner, Frank Slip-Stacked J-Aggregate Materials for Organic Solar Cells and Photodetectors Dye-dye interactions affect the optical and electronic properties in organic semiconductor films of light harvesting and detecting optoelectronic applications. This review elaborates how to tailor these properties of organic semiconductors for organic solar cells (OSCs) and organic photodiodes (OPDs). While these devices rely on similar materials, the demands for their optical properties are rather different, the former requiring a broad absorption spectrum spanning from the UV over visible up to the near-infrared region and the latter an ultra-narrow absorption spectrum at a specific, targeted wavelength. In order to design organic semiconductors satisfying these demands, fundamental insights on the relationship of optical properties are provided depending on molecular packing arrangement and the resultant electronic coupling thereof. Based on recent advancements in the theoretical understanding of intermolecular interactions between slip-stacked dyes, distinguishing classical J-aggregates with predominant long-range Coulomb coupling from charge transfer (CT)-mediated or -coupled J-aggregates, whose red-shifts are primarily governed by short-range orbital interactions, is suggested. Within this framework, the relationship between aggregate structure and functional properties of representative classes of dye aggregates is analyzed for the most advanced OSCs and wavelength-selective OPDs, providing important insights into the rational design of thin-film optoelectronic materials. 2022 Advanced Materials 34 22 urn:nbn:de:bvb:20-opus-276537 10.1002/adma.202104678 Institut für Organische Chemie OPUS4-29909 Wissenschaftlicher Artikel Menekse, Kaan; Renner, Rebecca; Mahlmeister, Bernhard; Stolte, Matthias; Würthner, Frank Bowl-shaped naphthalimide-annulated corannulene as nonfullerene acceptor in organic solar cells 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. 2020 229–234 Organic Materials 2 3 urn:nbn:de:bvb:20-opus-299095 10.1055/s-0040-1714283 Institut für Organische Chemie OPUS4-25637 Wissenschaftlicher Artikel Kim, Jin Hong; Liess, Andreas; Stolte, Matthias; Krause, Ana-Maria; Stepanenko, Vladimir; Zhong, Chuwei; Bialas, David; Spano, Frank; Würthner, Frank An Efficient Narrowband Near-Infrared at 1040 nm Organic Photodetector Realized by Intermolecular Charge Transfer Mediated Coupling Based on a Squaraine Dye 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. 2021 Advanced Materials 33 26 urn:nbn:de:bvb:20-opus-256374 10.1002/adma.202100582 Institut für Organische Chemie OPUS4-31259 Wissenschaftlicher Artikel Brust, Felix; Nagler, Oliver; Shoyama, Kazutaka; Stolte, Matthias; Würthner, Frank Organic Light-Emitting Diodes Based on Silandiol-Bay-Bridged Perylene Bisimides 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. 2023 Advanced Optical Materials 11 5 urn:nbn:de:bvb:20-opus-312599 10.1002/adom.202202676 Institut für Organische Chemie OPUS4-20480 Wissenschaftlicher Artikel Schmidt, David; Stolte, Matthias; Süß, Jasmin; Liess, Dr. Andreas; Stepanenko, Vladimir; Würthner, Frank Protein-like enwrapped perylene bisimide chromophore as bright microcrystalline emitter material 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. 2019 13385-13389 Angewandte Chemie International Edition 58 38 urn:nbn:de:bvb:20-opus-204809 10.1002/ange.201907618 Institut für Organische Chemie OPUS4-31209 Wissenschaftlicher Artikel Menekse, Kaan; Mahl, Magnus; Albert, Julius; Niyas, M. A.; Shoyama, Kazutaka; Stolte, Matthias; Würthner, Frank Supramolecularly Engineered Bulk-Heterojunction Solar Cells with Self-Assembled Non-Fullerene Nanographene Tetraimide Acceptors A series of novel imide-functionalized C\(_{64}\) nanographenes is investigated as acceptor components in organic solar cells (OSCs) in combination with donor polymer PM6. These electron-poor molecules either prevail as a monomer or self-assemble into dimers in the OSC active layer depending on the chosen imide substituents. This allows for the controlled stacking of electron-poor and electron-rich π-scaffolds to establish a novel class of non-fullerene acceptor materials to tailor the bulk-heterojunction morphology of the OSCs. The best performance is observed for derivatives that are able to self-assemble into dimers, reaching power conversion efficiencies of up to 7.1%. 2023 Solar RRL 7 2 urn:nbn:de:bvb:20-opus-312099 10.1002/solr.202200895 Institut für Organische Chemie OPUS4-31224 Wissenschaftlicher Artikel Sun, Meng-Jia; Anhalt, Olga; Sárosi, Menyhárt B.; Stolte, Matthias; Würthner, Frank Activating Organic Phosphorescence via Heavy Metal-π Interaction Induced Intersystem Crossing Heavy-atom-containing clusters, nanocrystals, and other semiconductors can sensitize the triplet states of their surface-bonded chromophores, but the energy loss, such as nonradiative deactivation, often prevents the synergistic light emission in their solid-state coassemblies. Cocrystallization allows new combinations of molecules with complementary properties for achieving functionalities not available in single components. Here, the cocrystal formation that employs platinum(II) acetylacetonate (Pt(acac)\(_{2}\)) as a triplet sensitizer and electron-deficient 1,4,5,8-naphthalene diimides (NDIs) as organic phosphors is reported. The hybrid cocrystals exhibit room-temperature phosphorescence confined in the low-lying, long-lived triplet state of NDIs with photoluminescence (PL) quantum yield (Φ\(_{PL}\)) exceeding 25% and a phosphorescence lifetime (τ\(_{Ph}\)) of 156 µs. This remarkable PL property benefits from the noncovalent electronic and spin-orbital coupling between the constituents. 2022 Advanced Materials 34 51 urn:nbn:de:bvb:20-opus-312248 10.1002/adma.202207331 Institut für Organische Chemie OPUS4-20439 Wissenschaftlicher Artikel Renner, Rebecca; Stolte, Matthias; Würthner, Frank Self-Assembly of bowl-shaped naphthalimide-annulated corannulene The self-assembly of a bowl-shaped naphthalimide-annulated corannulene of high solubility has been studied in a variety of solvents by NMR and UV/Vis spectroscopy. Evaluation by the anti-cooperative K\(_2\)-K model revealed the formation of supramolecular dimers of outstanding thermodynamic stability. Further structural proof for the almost exclusive formation of dimers over extended aggregates is demonstrated by atomic force microscopy (AFM) and diffusion ordered spectroscopy (DOSY) measurements as well as by theoretical calculations. Thus, herein we present the first report of a supramolecular dimer of an annulated corannulene derivative in solution and discuss its extraordinarily high thermodynamic stability with association constants up to > 10\(^6\)M\(^-\) \(^1\) in methylcyclohexane, which is comparable to the association constants given for planar phthalocyanine and perylene bisimide dyes. 2020 32-39 ChemistryOpen 9 1 urn:nbn:de:bvb:20-opus-204396 10.1002/open.201900291 Institut für Organische Chemie OPUS4-24907 Wissenschaftlicher Artikel Renner, Rebecca; Mahlmeister, Bernhard; Anhalt, Olga; Stolte, Matthias; Würthner, Frank Chiral Perylene Bisimide Dyes by Interlocked Arene Substituents in the Bay Area 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. 2021 10 Chemistry - A European Journal 27 46 11997 12006 urn:nbn:de:bvb:20-opus-249070 10.1002/chem.202101877 Institut für Organische Chemie OPUS4-25656 Wissenschaftlicher Artikel Bold, Kevin; Stolte, Matthias; Shoyama, Kazutaka; Holzapfel, Marco; Schmiedel, Alexander; Lambert, Christoph; Würthner, Frank Macrocyclic donor-acceptor dyads composed of a perylene bisimide dye surrounded by oligothiophene bridges Two macrocyclic architectures comprising oligothiophene strands that connect the imide positions of a perylene bisimide (PBI) dye have been synthesized via a platinum-mediated cross-coupling strategy. The crystal structure of the double bridged PBI reveals all syn-arranged thiophene units that completely enclose the planar PBI chromophore via a 12-membered macrocycle. The target structures were characterized by steady-state UV/Vis absorption, fluorescence and transient absorption spectroscopy, as well as cyclic and differential pulse voltammetry. Both donor-acceptor dyads show ultrafast Förster Resonance Energy Transfer and photoinduced electron transfer, thereby leading to extremely low fluorescence quantum yields even in the lowest polarity cyclohexane solvent. 2022 Angewandte Chemie Internationale Edition 61 1 urn:nbn:de:bvb:20-opus-256569 10.1002/anie.202113598 Institut für Organische Chemie OPUS4-27643 Wissenschaftlicher Artikel Bold, Kevin; Stolte, Matthias; Shoyama, Kazutaka; Krause, Ana-Maria; Schmiedel, Alexander; Holzapfel, Marco; Lambert, Christoph; Würthner, Frank Macrocyclic Donor-Acceptor Dyads Composed of Oligothiophene Half-Cycles and Perylene Bisimides 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. 2022 Chemistry – A European Journal 28 30 urn:nbn:de:bvb:20-opus-276435 10.1002/chem.202200355 Institut für Organische Chemie OPUS4-24476 Wissenschaftlicher Artikel Schembri, Tim; Kim, Jin Hong; Liess, Andreas; Stepanenko, Vladimir; Stolte, Matthias; Würthner, Frank Semitransparent Layers of Social Self-Sorting Merocyanine Dyes for Ultranarrow Bandwidth Organic Photodiodes Two dipolar merocyanines consisting of the same π-conjugated chromophore but different alkyl substituents adopt very different packing arrangements in their respective solid state with either H- or J-type exciton coupling, leading to ultranarrow absorption bands at 477 and 750 nm, respectively, due to exchange narrowing. The social self-sorting behavior of these push-pull chromophores in their mixed thin films is evaluated and the impact on morphology as well as opto-electronical properties is determined. The implementation of this well-tuned two-component material with tailored optical features allows to optimize planar heterojunction organic photodiodes with fullerene ​(C\(_{60}\)) with either dual or single wavelength selectivity in the blue and NIR spectral range with ultranarrow bandwidths of only 11 nm (200 cm\(^{-1}\)) and an external quantum efficiency of up to 18% at 754 nm under 0 V bias. The application of these photodiodes as low-power consuming heart rate monitors is demonstrated by a reflectance-mode photoplethysmography (PPG) sensor. 2021 Advanced Optical Materials 9 15 urn:nbn:de:bvb:20-opus-244762 10.1002/adom.202100213 Institut für Organische Chemie OPUS4-21822 Wissenschaftlicher Artikel Stolte, Matthias; Hecht, Reinhard; Xie, Zengqi; Liu, Linlin; Kaufmann, Christina; Kudzus, Astrid; Schmidt, David; Würthner, Frank Crystal Engineering of 1D Exciton Systems Composed of Single- and Double-Stranded Perylene Bisimide J-Aggregates Single crystals of three at bay area tetraphenoxy-substituted perylene bisimide dyes are grown by vacuum sublimation. X-ray analysis reveals the self-assembly of these highly twisted perylene bisimides (PBIs) in the solid state via imide-imide hydrogen bonding into hydrogen-bonded PBI chains. The crystallographic insights disclose that the conformation and sterical congestion imparted by the phenoxy substituents can be controlled by ortho-substituents. Accordingly, whilst sterically less demanding methyl and isopropyl substituents afford double-stranded PBI chains of complementary P and M atropo-enantiomers, single hydrogen-bonded chains of homochiral PBIs are observed for the sterically more demanding ortho-phenyl substituents. Investigation of the absorption and fluorescence properties of microcrystals and thin films of these PBIs allow for an unambiguous interpretation of these exciton systems. Thus, the J-aggregates of the double-stranded crystals exhibit a much larger (negative) exciton coupling than the single-stranded one, which in contrast has the higher solid-state fluorescence quantum yield. 2020 Advanced Optical Materials 8 18 urn:nbn:de:bvb:20-opus-218221 10.1002/adom.202000926 Institut für Organische Chemie