The research programme of our group
Our research is devoted to the development of advanced organic materials based on functional dyes such as perylene and naphthalene bisimides, merocyanines, squaraines, chlorins and diketopyrrolopyrroles by employing supramolecular approaches. Towards this objective, we design and synthesize novel molecular building blocks and explore their self-assembly into nanoscale architectures and liquid-crystalline and crystalline solid-state materials that are applied in (opto-)electronic and photovoltaic devices as weil as in photocatalytic water splitting.
Our current research topics:
Synthetic Dye Chemistry
An important advantage of molecular materials is given by the possibility to tune theirfunctional properties by proper choice of the core structure and attachment of suitablesubstituents. This, together with control of their packing arrangements, affords functionalmaterials for various purposes. In our current research we develop new synthetic strategiesto one- and twodimensional p-scaffolds (das p ist ein griechisch "pi") by palladium-catalyzedcoupling-annulation cascade reactions. With regard to properties we are interested influorescence and phosphorescence, HOMO and LUMO levels and biradical character.
M. Gsänger et al., Angew. Chem. Int. Ed. 2010, 49, 740-743; A Crystal-Engineered Hydrogen-Bonded Octachloroperylene Diimide with a TwistedCore: An n-Channel Organic Semiconductor DOI: 10.1002/anie.200904215
S. Seifert et al., Angew. Chem. Int. Ed. 2016, 55, 6390-6395; An Electron-Poor C64 Nanographene by Palladium-Catalyzed Cascade C-C BondFormation: One-Pot Synthesis and Single-Crystal Structure Analysis DOI: 10.1002/anie.201601433
K. Shoyama et al., Org. Lett. 2017, 19; 5328–5331; Electron-Poor Bowl-Shaped Polycyclic Aromatic Dicarboximides: Synthesis, Crystal Structures, and Optical and Redox PropertiesDOI: 10.1021/acs.orglett.7b02618
Mechanistic elucidation, including thermodynamic and kinetic analyses of self-assembly processes of functional dyes by UV/Vis/NIR absorption, fluorescence and CD spectroscopy and isothermal titration calorimetry. Structural and morphological characterization of supramolecular assemblies by 2D NMR, DLS, high-resolution MS, AFM, STM, SEM and TEM. Exploration of electrochemical and photo-physical properties of supramolecular assemblies by cyclic voltammetry, spectroelectrochemistry and time-resolved spectroscopy.
F. Würthner et al., Chem. Rev., 2016, 116 (3), 962–1052 ; Perylene Bisimide Dye Assemblies as Archetype Funktional Supramolecular Materials.DOI: 10.1021/acs.chemrev.5b00188
C. Shao et al., Angew. Chem. Int. Ed. 2013, 52, 7482-7486; Quadruple π Stack of Two Perylene Bisimide Tweezers: A Bimolecular Complex with Kinetic Stability.DOI: 10.1002/anie.201302479
J. Sung et al., Nat. Commun. 2015, Direct Observation of Ultrafast Coherent Exciton Dynamics in Helical π Stacks of Self-assembled Perylene Bisimides.DOI: 10.1038/ncomms9646
Supramolecular Polymers and Soft Matter
Construction of supramolecular polymers and block copolymers of functional dyes by seeded living polymerization and elucidation of their (opto) electronic properties. Developmentof thermotropic and lyotropic (chromonic) liquid-crystalline and gel materials based on H-bonding perylene bisimides and squaraines. Analysis of condensed phase materials by POM, DSC and XRD techniques.
X. Zhang et. al., Nature Chem. 2009, 1, 623–62; Vesicular Perylene Dye Nanocapsules as Supramolecular Fluorescent pH Sensor SystemsDOI: 10.1038/nchem.368
S. Ogi et al., J. Am. Chem. Soc., 2015, 137, 3300-3307; Mechanism of Self-Assembly Process and Seeded Supramole-cular Polymerization of Perylene Bisimide Organogelator.DOI: 10.1021/ja511952c
D. Görl et al., Nat. Commun. 2015, 6, 7009; Supramolecular block copolymers by kinetically controlled co-self-assembly of planar and core-twisted perylene bisimides.DOI:10.1038/ncomms8009
lnteraction with Biomacromolecules
Development of water-soluble fluorescent dyes and their supramolecular assemblies and exploration of their interactions with biological components like DNA, proteins, and cellular systems for sensing, imaging and therapeutic applications
J. M Farrell, et at., Angew. Chem., Int. Ed., A Doubly Boron-Doped Perylene by N-Heterocylic Carbene-Borenium Hydroboration—C-H Borylation—Dehydrogenation
First published July 25th, 2017,
J. Gershberg et al., Chem. Eur. J. 2015, 21, 7886-7895; Sensing of Double-Stranded DNA/RNA Secondary Structures by Water Soluble Homochiral Perylene Bisimide Dyes.DOI: 10.1002/chem.201500184
F-P. Gao et al., Biomaterials 2014, 35, 1004-1014; Supramolecular Adducts of Squaraine and Protein for Noninvasive Tumor Imaging and Photothermal Therapy in Vivo.DOI: 10.1016/j.biomaterials.2013.10.039
Development of multicomponent architectures containing functional dye based light harvesting antennae systems and photosensitizers as solar fuel production catalysts for the implementation into photo-reactors. Construction of metallosupramolecular architectures like one-dimensional nanofibers or two-dimensional macrocycles containing ruthenium water oxidation catalysts.
V. Kunz et al., Energy Environ. Sci. 2017, 10, 2137-2153, Cooperative water oxidation catalysis in a series of trinuclear metallosupramolecular ruthenium macrocyclesDOI: 10.1039/c7ee01557g
M. Schulze et al., Nature Chemistry, 2016, 8 , 576–583, A Supramolecular Ruthenium Macrocycle with High Catalytic Activity for Water Oxidation that Mechanically Mimics Photosystem IIDOI:10.1038/nchem.2503
P. Frischmann et al., Chem. Soc. Rev. 2013, 42, 1847–1870, Powering the Future of Molecular Artificial Photosynthesis with Light-Harvesting Metallosupramolecular Dye AssembliesDOI: 10.1039/c2cs35223k
Organic Electronics & Photovoltaics
Highly purified functional small molecules can be processed either from solution or by sublimation in vacuum to investigate their propensity as solid state materials for applications in organic thin-film transistors and organic bulk heterojunction solar cells. Structure properties relationships are established by correlation between single crystal and thin-film X-ray analysis.
A. Lv et al., Angew. Chem. Int. Ed, 2015, 54, 10512-10515; Head-to-Tail Zig Zag Packing of Dipolar Merocyanine Dyes Affords High-Performance Organic Thin-Film Transistors.DOI: 10.1002/anie.201504190
T. He et al., Nat. Commun. 2015, 6, 5954; Single-Crystall Field-Effect Transistors of new CI2-NDI Polymorph Processed by Sublimation in Air.DOI:10.1038/ncomms6954
A. Arjona-Esteban et al., J. Am. Chem. Soc. 2015, 137, DOI: 10.1021/jacs.5b08386 Influence of solid state packing of dipolar merocyanine dyes on transistor and solar cell performance.DOI: 10.1021/jacs.5b06722