Fluorescence Excitation Spectra from Individual Chlorosomes of the Green Sulfur Bacterium <i>Chlorobaculum tepidum</i>

Jendrny, Marc; Aartsma, Thijs J.; Köhler, Jürgen

doi:10.1021/jz301808h

Cited by 22 publications

(31 citation statements)

References 40 publications

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“…Examples of such systems include the natural light-harvesting complexes of chlorophyll molecules that appear in photosynthetic bacteria and plants [4][5][6][7][8], as well as aggregates formed by synthetic dye molecules, such as the well-known class of J-aggregates formed by cyanine molecules [3,[9][10][11][12]. The strong resonance interactions between the aggregated molecules in these systems give rise to charge-neutral, collective electronic excitations called Frenkel excitons [13,14].…”

Section: Introductionmentioning

confidence: 99%

Vibronic effects and destruction of exciton coherence in optical spectra of J-aggregates: A variational polaron transformation approach

et al. 2016

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Using a symmetry adapted polaron transformation of the Holstein Hamiltonian, we study the interplay of electronic excitation-vibration couplings, resonance excitation transfer interactions, and temperature in the linear absorption spectra of molecular J-aggregates. Semi-analytical expressions for the spectra are derived and compared with results obtained from direct numerical diagonalization of the Hamiltonian in the two-particle basis set representation. At zero temperature, we show that our polaron transformation reproduces both the collective (exciton) and single-molecule (vibrational) optical response associated with the appropriate standard perturbation limits. Specifically, for the molecular dimer excellent agreement with the spectra from the two-particle approach for the entire range of model parameters is obtained. This is in marked contrast to commonly used polaron transformations. Upon increasing the temperature, the spectra show a transition from the collective to the individual molecular features, which results from the thermal destruction of the exciton coherence.

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Section: Introductionmentioning

confidence: 99%

Vibronic effects and destruction of exciton coherence in optical spectra of J-aggregates: A variational polaron transformation approach

et al. 2016

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“…5,7,[18][19][20] A prominent example of tubular molecular aggregates is derived from meso-tetra(4-sulfonatophenyl) porphyrin (TPPS4) and provides a biomimetic analogue of the chlorosomes of green sulfur bacteria. 9,[21][22][23][24] The structure of TPPS4 tubular aggregates has been characterized by small angle X-ray scattering, atomic force microscopy (AFM), and cryo-electron microscopy. [25][26][27][28][29][30][31][32][33] TPPS4 tubular aggregates are found to be cylindrical structures with a diameter of approximately 16-18 nm 31,33 and a length up to several microns.…”

Section: Introductionmentioning

confidence: 99%

Exciton Level Structure and Dynamics in Tubular Porphyrin Aggregates

Wan

Stradomska²,

Fong

et al. 2014

J. Phys. Chem. C

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We present an account of the optical properties of the Frenkel excitons in self-assembled porphyrin tubular aggregates that represent an analog to natural photosynthetic antennae. Using a combination of ultrafast optical spectroscopy and stochastic exciton modeling, we address both linear and nonlinear exciton absorption, band) resulting from strong intermolecular coupling in these aggregates could potentially facilitate efficient energy transfer, fast relaxation due to defects and disorder probably present a major limitation for exciton transport over large distances. 3 Keywords:Frenkel exciton, biomimetic photosynthetic antennae, ultrafast spectroscopy, stochastic exciton modeling 4

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“…T he most remarkable materials that demonstrate the ability to capture solar energy are natural photosynthetic systems such as those found in primitive marine algae and bacteria (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). Their light-harvesting (LH) antennae are crucial components, because they absorb the light and direct the resulting excitation energy efficiently to a reaction center, which then converts these excitations (excitons) into charge-separated states (1,4,11,12).…”

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confidence: 99%

Robust excitons inhabit soft supramolecular nanotubes

Eisele¹,

Arias²,

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

115

206

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Nature's highly efficient light-harvesting antennae, such as those found in green sulfur bacteria, consist of supramolecular building blocks that self-assemble into a hierarchy of close-packed structures. In an effort to mimic the fundamental processes that govern nature's efficient systems, it is important to elucidate the role of each level of hierarchy: from molecule, to supramolecular building block, to close-packed building blocks. Here, we study the impact of hierarchical structure. We present a model system that mirrors nature's complexity: cylinders self-assembled from cyanine-dye molecules. Our work reveals that even though close-packing may alter the cylinders' soft mesoscopic structure, robust delocalized excitons are retained: Internal order and strong excitation-transfer interactions-prerequisites for efficient energy transport-are both maintained. Our results suggest that the cylindrical geometry strongly favors robust excitons; it presents a rational design that is potentially key to nature's high efficiency, allowing construction of efficient lightharvesting devices even from soft, supramolecular materials. supramolecular assembly | self-assembled excitonic nanoscale systems | photosynthesis | exciton theory | light-harvesting antennae systems T he most remarkable materials that demonstrate the ability to capture solar energy are natural photosynthetic systems such as those found in primitive marine algae and bacteria (1-10). Their light-harvesting (LH) antennae are crucial components, because they absorb the light and direct the resulting excitation energy efficiently to a reaction center, which then converts these excitations (excitons) into charge-separated states (1,4,11,12). Although the noncovalent interactions that link the individual molecules within the LH antennae are weak, the excitation transfer interactions between the molecules are relatively strong; new excited states, so-called Frenkel excitons (13), are generated that are delocalized over a number of molecules (1). These delocalized excitons are key to nature's efficiency and are therefore of high interest (14)(15)(16)(17)(18)(19)(20).To create such efficient LH systems, nature assembles molecular subunits into individual supramolecular structures, which are then further assembled into close-packed superstructures (1, 4, 7-10, 12, 21). This hierarchical assembly is a generic motif of nature's photosynthetic systems. As with natural systems, assembling artificial LH devices from supramolecular structures will require close packing into hierarchical assemblies to maximize the amount of absorbed light (19). Therefore, key to our ability to tune materials properties for efficient LH applications is a basic understanding of the role of each level of the hierarchy: from the individual molecule, to the individual supramolecular building block, to the close-packed assembly. Whereas the role of the individual molecules in the excitonic properties of the building blocks is well-studied (1, 7-10, 20, 22-37), the effect of structural hierar...

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Fluorescence Excitation Spectra from Individual Chlorosomes of the Green Sulfur Bacterium Chlorobaculum tepidum

Cited by 22 publications

References 40 publications

Vibronic effects and destruction of exciton coherence in optical spectra of J-aggregates: A variational polaron transformation approach

Vibronic effects and destruction of exciton coherence in optical spectra of J-aggregates: A variational polaron transformation approach

Exciton Level Structure and Dynamics in Tubular Porphyrin Aggregates

Robust excitons inhabit soft supramolecular nanotubes

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