Limitations of linear dichroism spectroscopy for elucidating structural issues of light-harvesting aggregates in chlorosomes

Lisa M. Günther, Jasper Knoester, Jürgen Köhler*

*Bijbehorende auteur voor dit werk

    OnderzoeksoutputAcademicpeer review

    3 Citaten (Scopus)
    1 Downloads (Pure)

    Samenvatting

    Linear dichroism (LD) spectroscopy is a widely used technique for studying the mutual orientation of the transition-dipole moments of the electronically excited states of molecular aggregates. Often the method is applied to aggregates where detailed information about the geometrical arrangement of the monomers is lacking. However, for complex molecular assemblies where the monomers are assembled hierarchically in tiers of supramolecular structural elements, the method cannot extract well-founded information about the monomer arrangement. Here we discuss this difficulty on the example of chlorosomes, which are the light-harvesting aggregates of photosynthetic green-(non) sulfur bacteria. Chlorosomes consist of hundreds of thousands of bacteriochlorophyll molecules that self-assemble into secondary structural elements of curved lamellar or cylindrical morphology. We exploit data from polarization-resolved fluorescence-excitation spectroscopy performed on single chlorosomes for reconstructing the corresponding LD spectra. This reveals that LD spectroscopy is not suited for benchmarking structural models in particular for complex hierarchically organized molecular supramolecular assemblies.

    Originele taal-2English
    Artikelnummer899
    Aantal pagina's16
    TijdschriftMolecules
    Volume26
    Nummer van het tijdschrift4
    DOI's
    StatusPublished - 2-feb-2021

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