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  1. Article ; Online: Spatial Correlations Drive Long-Range Transport and Trapping of Excitons in Single H-Aggregates: Experiment and Theory.

    Carta, Alberto / Wittmann, Bernd / Kreger, Klaus / Schmidt, Hans-Werner / Jansen, Thomas L C / Hildner, Richard

    The journal of physical chemistry letters

    2024  Volume 15, Issue 10, Page(s) 2697–2707

    Abstract: Describing long-range energy transport is a crucial step, both toward deepening our knowledge on natural light-harvesting systems and toward developing novel photoactive materials. Here, we combine experiment and theory to resolve and reproduce energy ... ...

    Abstract Describing long-range energy transport is a crucial step, both toward deepening our knowledge on natural light-harvesting systems and toward developing novel photoactive materials. Here, we combine experiment and theory to resolve and reproduce energy transport on pico- to nanosecond time scales in single H-type supramolecular nanofibers based on carbonyl-bridged triarylamines (CBT). Each nanofiber shows energy transport dynamics over long distances up to ∼1 μm, despite exciton trapping at specific positions along the nanofibers. Using a minimal Frenkel exciton model including disorder, we demonstrate that spatial correlations in the normally distributed site energies are crucial to reproduce the experimental data. In particular, we can observe the long-range and subdiffusive nature of the exciton dynamics as well as the trapping behavior of excitons in specific locations of the nanofiber. This trapping behavior introduces a net directionality or asymmetry in the exciton dynamics as observed experimentally.
    Language English
    Publishing date 2024-03-01
    Publishing country United States
    Document type Journal Article
    ISSN 1948-7185
    ISSN (online) 1948-7185
    DOI 10.1021/acs.jpclett.3c03586
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Thesis: Ärztliche Aufklärungspflicht unter besonderer Berücksichtigung der Zahn-, Mund- und Kieferheilkunde

    Kreger, Klaus

    e. krit. Übersicht

    1984  

    Size VII, 153 S.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis München, Univ., Diss., 1984
    HBZ-ID HT003220805
    Database Catalogue ZB MED Medicine, Health

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    In stock of ZB MED Cologne/Königswinter

    Shelf markLoan statusLocation
    85 D 3622 order for loan Magazin

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  3. Article ; Online: Directed Gradients in the Excited-State Energy Landscape of Poly(3-hexylthiophene) Nanofibers.

    Stäter, Sebastian / Wenzel, Felix A / Welz, Hannes / Kreger, Klaus / Köhler, Jürgen / Schmidt, Hans-Werner / Hildner, Richard

    Journal of the American Chemical Society

    2023  Volume 145, Issue 25, Page(s) 13780–13787

    Abstract: Funneling excitation energy toward lower energy excited states is a key concept in photosynthesis, which is often realized with at most two chemically different types of pigment molecules. However, current synthetic approaches to establish energy funnels, ...

    Abstract Funneling excitation energy toward lower energy excited states is a key concept in photosynthesis, which is often realized with at most two chemically different types of pigment molecules. However, current synthetic approaches to establish energy funnels, or gradients, typically rely on Förster-type energy-transfer cascades along many chemically different molecules. Here, we demonstrate an elegant concept for a gradient in the excited-state energy landscape along micrometer-long supramolecular nanofibers based on the conjugated polymer poly(3-hexylthiophene), P3HT, as the single component. Precisely aligned P3HT nanofibers within a supramolecular superstructure are prepared by solution processing involving an efficient supramolecular nucleating agent. Employing hyperspectral imaging, we find that the lowest-energy exciton band edge continuously shifts to lower energies along the nanofibers' growth direction. We attribute this directed excited-state energy gradient to defect fractionation during nanofiber growth. Our concept provides guidelines for the design of supramolecular structures with an intrinsic energy gradient for nanophotonic applications.
    Language English
    Publishing date 2023-06-14
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.3c02117
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Bonn / Germany

    Z 4' 55/32: Show issues
    Z 7.3: Show issues

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  4. Article ; Online: Electrogelation: Controlled Fast Formation of Micrometer-Thick Films from Low-Molecular Weight Hydrogelators.

    Raßmann, Nadine / Weber, Melina / Glaß, Roman E J / Kreger, Klaus / Helfricht, Nicolas / Schmidt, Hans-Werner / Papastavrou, Georg

    Langmuir : the ACS journal of surfaces and colloids

    2023  Volume 39, Issue 48, Page(s) 17190–17200

    Abstract: The controlled electrochemical deposition of hydrogels from low-molecular weight hydrogelators (LMWHGs) allows for the defined formation of thin films on electrodes. Here, the deposition of fibrillar networks consisting ... ...

    Abstract The controlled electrochemical deposition of hydrogels from low-molecular weight hydrogelators (LMWHGs) allows for the defined formation of thin films on electrodes. Here, the deposition of fibrillar networks consisting of
    Language English
    Publishing date 2023-11-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021/acs.langmuir.3c02270
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Stable Mesoscale Nonwovens of Electrospun Polyacrylonitrile and Interpenetrating Supramolecular 1,3,5-Benzenetrisamide Fibers as Efficient Carriers for Gold Nanoparticles

    Drummer, Markus / Liang, Zhen / Kreger, Klaus / Rosenfeldt, Sabine / Greiner, Andreas / Schmidt, Hans-Werner

    ACS applied materials & interfaces. 2021 July 13, v. 13, no. 29 p.34818-34828

    2021  

    Abstract: The immobilization of metal nanoparticles without agglomeration and leaching within composite nonwovens is often challenging and of great importance, for example, for catalytic applications. In this study, we prepared composite nonwovens based on ... ...

    Abstract The immobilization of metal nanoparticles without agglomeration and leaching within composite nonwovens is often challenging and of great importance, for example, for catalytic applications. In this study, we prepared composite nonwovens based on electrospun polyacrylonitrile (PAN) short fibers and supramolecular terpyridine-functionalized benzene-1,3,5-tricarboxamide (BTA1) nanofibers by a sheet-forming wet-laid process. The formation of an interpenetrating and entangled network of supramolecular BTA1 nanofibers and PAN short fibers results in mechanically stable mesoscale nonwovens. Because of the peripheral terpyridine substituents of the BTA1, nonaggregated gold nanoparticles (AuNPs) could be immobilized efficiently in the composite nonwovens. The functionality of the resulting AuNPs-loaded composite nonwovens was verified by catalytic reduction of 4-nitrophenol to 4-aminophenol as a standard model reaction. The AuNPs-loaded PAN/BTA1 composite nonwovens showed high catalytic activity, reusability, and excellent stability.
    Keywords aminophenols ; catalytic activity ; nanofibers ; nanogold ; nonwoven fabrics ; p-nitrophenol ; polyacrylonitrile ; composite nonwovens ; catalysis ; electrospun fibers ; gold nanoparticles ; supramolecular fibers ; wet-laid technique
    Language English
    Dates of publication 2021-0713
    Size p. 34818-34828.
    Publishing place American Chemical Society
    Document type Article ; Online
    ISSN 1944-8252
    DOI 10.1021/acsami.1c06442
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: Supramolecular microtubes based on 1,3,5-benzenetricarboxamides prepared by self-assembly upon heating.

    Frank, Andreas / Bernet, Andreas / Kreger, Klaus / Schmidt, Hans-Werner

    Soft matter

    2020  Volume 16, Issue 19, Page(s) 4564–4568

    Abstract: A series of three 1,3,5-benzenetricarboxamides with peripheral tertiary N,N-dialkyl-ethylamino substituents with different length of the alkyl groups is reported. In particular, the ... ...

    Abstract A series of three 1,3,5-benzenetricarboxamides with peripheral tertiary N,N-dialkyl-ethylamino substituents with different length of the alkyl groups is reported. In particular, the N
    Language English
    Publishing date 2020-04-03
    Publishing country England
    Document type Journal Article
    ZDB-ID 2191476-X
    ISSN 1744-6848 ; 1744-683X
    ISSN (online) 1744-6848
    ISSN 1744-683X
    DOI 10.1039/d0sm00268b
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: All-optical manipulation of singlet exciton transport in individual supramolecular nanostructures by triplet gating.

    Wittmann, Bernd / Biskup, Till / Kreger, Klaus / Köhler, Jürgen / Schmidt, Hans-Werner / Hildner, Richard

    Nanoscale horizons

    2021  Volume 6, Issue 12, Page(s) 998–1005

    Abstract: Directed transport of singlet excitation energy is a key process in natural light-harvesting systems and a desired feature in assemblies of functional organic molecules for organic electronics and nanotechnology applications. However, progress in this ... ...

    Abstract Directed transport of singlet excitation energy is a key process in natural light-harvesting systems and a desired feature in assemblies of functional organic molecules for organic electronics and nanotechnology applications. However, progress in this direction is hampered by the lack of concepts and model systems. Here we demonstrate an all-optical approach to manipulate singlet exciton transport pathways within supramolecular nanostructures
    MeSH term(s) Lasers ; Light ; Nanostructures ; Photons
    Language English
    Publishing date 2021-11-22
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 2055-6764
    ISSN (online) 2055-6764
    DOI 10.1039/d1nh00514f
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Stable Mesoscale Nonwovens of Electrospun Polyacrylonitrile and Interpenetrating Supramolecular 1,3,5-Benzenetrisamide Fibers as Efficient Carriers for Gold Nanoparticles.

    Drummer, Markus / Liang, Chen / Kreger, Klaus / Rosenfeldt, Sabine / Greiner, Andreas / Schmidt, Hans-Werner

    ACS applied materials & interfaces

    2021  Volume 13, Issue 29, Page(s) 34818–34828

    Abstract: The immobilization of metal nanoparticles without agglomeration and leaching within composite nonwovens is often challenging and of great importance, for example, for catalytic applications. In this study, we prepared composite nonwovens based on ... ...

    Abstract The immobilization of metal nanoparticles without agglomeration and leaching within composite nonwovens is often challenging and of great importance, for example, for catalytic applications. In this study, we prepared composite nonwovens based on electrospun polyacrylonitrile (PAN) short fibers and supramolecular terpyridine-functionalized benzene-1,3,5-tricarboxamide (
    Language English
    Publishing date 2021-07-13
    Publishing country United States
    Document type Journal Article
    ISSN 1944-8252
    ISSN (online) 1944-8252
    DOI 10.1021/acsami.1c06442
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Hierarchical Superstructures by Combining Crystallization-Driven and Molecular Self-Assembly.

    Frank, Andreas / Hils, Christian / Weber, Melina / Kreger, Klaus / Schmalz, Holger / Schmidt, Hans-Werner

    Angewandte Chemie (International ed. in English)

    2021  Volume 60, Issue 40, Page(s) 21767–21771

    Abstract: Combining the unique corona structure of worm-like patchy micelles immobilized on a polymer fiber with the molecular self-assembly of 1,3,5-benzenetricarboxamides (BTAs) leads to hierarchical superstructures with a fir-tree-like morphology. For this ... ...

    Abstract Combining the unique corona structure of worm-like patchy micelles immobilized on a polymer fiber with the molecular self-assembly of 1,3,5-benzenetricarboxamides (BTAs) leads to hierarchical superstructures with a fir-tree-like morphology. For this purpose, worm-like patchy micelles bearing pendant, functional tertiary amino groups in one of the corona patches were prepared by crystallization-driven self-assembly and immobilized on a supporting polystyrene fiber by coaxial electrospinning. The obtained patchy fibers were then immersed in an aqueous solution of a tertiary amino-functionalized BTA to induce patch-mediated molecular self-assembly to well-defined fir-tree-like superstructures upon solvent evaporation. Interestingly, defined superstructures are obtained only if the pendant functional groups in the surface patches match with the peripheral substituents of the BTA, which is attributed to a local increase in BTA concentration at the polymer fibers' surface.
    Language English
    Publishing date 2021-06-17
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202105787
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  10. Article ; Online: Crystal Engineering of Supramolecular 1,4-Benzene Bisamides by Side-Chain Modification - Towards Tuneable Anisotropic Morphologies and Surfaces.

    van der Zwan, Kasper P / Steinlein, Christoph / Kreger, Klaus / Schmidt, Hans-Werner / Senker, Jürgen

    Chemphyschem : a European journal of chemical physics and physical chemistry

    2021  Volume 22, Issue 24, Page(s) 2585–2593

    Abstract: Benzene bisamides are promising building blocks for supramolecular nano-objects. Their functionality depends on morphology and surface properties. However, a direct link between surface properties and molecular structure itself is missing for this ... ...

    Abstract Benzene bisamides are promising building blocks for supramolecular nano-objects. Their functionality depends on morphology and surface properties. However, a direct link between surface properties and molecular structure itself is missing for this material class. Here, we investigate this interplay for two series of 1,4-benzene bisamides with symmetric and asymmetric peripheral substitution. We elucidated the crystal structures, determined the nano-object morphologies and derived the wetting behaviour of the preferentially exposed surfaces. The crystal structures were solved by combining single-crystal and powder X-ray diffraction, solid-state NMR spectroscopy and computational modelling. Bulky side groups, here t-butyl groups, serve as a structure-directing motif into a packing pattern, which favours the formation of thin platelets. The use of slim peripheral groups on both sides, in our case linear perfluorinated, alkyl chains, self-assemble the benzene bisamides into a second packing pattern which leads to ribbon-like nano-objects. For both packing types, the preferentially exposed surfaces consist of the ends of the peripheral groups. Asymmetric substitution with bulky and slim groups leads to an ordered alternating arrangement of the groups exposed to the surface. This allows the hydrophobicity of the surfaces to be gradually altered. We thus identified two leitmotifs for molecular packings of benzene bisamides providing the missing link between the molecular structure, the anisotropic morphologies and adjustable surface properties of the supramolecular nano-objects.
    Language English
    Publishing date 2021-11-08
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2025223-7
    ISSN 1439-7641 ; 1439-4235
    ISSN (online) 1439-7641
    ISSN 1439-4235
    DOI 10.1002/cphc.202100597
    Database MEDical Literature Analysis and Retrieval System OnLINE

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