Surfactant-Induced Changes of Morphology of J-Aggregates:  Superhelix-to-Tubule Transformation

Berlepsch, Hans von; Böttcher, Christoph; Ouart, Andrè; Regenbrecht, M.; Akari, S.; Keiderling, U.; Schnablegger, Heimo; Dähne, S.; Kirstein, Stefan

doi:10.1021/la000014i

Cited by 97 publications

(110 citation statements)

References 41 publications

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“…[9][10][11][12][13] A number of other porphyrin derivatives, such as TPPS 2 (bi(4-sulfonatophenyl)diphenylporphyrin) and TPPS 3 (tri(4-sulfonatophenyl)phenylporphyrin), 14 TCPP (tetra(4-carboxyphenyl)porphyrin), 15 TPPS 4 (tetra(4-sulfonatophenyl)porphyrin), 16,17 or a mixture of TPPS 4 and SnTPyP (Sn(IV) tetra(4-pyridyl)porphyrin), 18 form aggregates of tubular morphology as well. However, in this paper, we will focus solely on the tubular TPPS 4 aggregates, because of their high stability and reproducibility of their structural and optical properties.…”

Section: Introductionmentioning

confidence: 99%

Exciton Spectra and the Microscopic Structure of Self-Assembled Porphyrin Nanotubes

et al. 2009

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Exciton spectra and the microscopic structure of self-assembled porphyrin nanotubes Vlaming, S. M.; Augulis, R.; Stuart, M. C. A.; Knoester, J.; van Loosdrecht, P. H. M. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands ReceiVed: September 16, 2008; ReVised Manuscript ReceiVed: December 11, 2008 The optical properties of tubular aggregates formed by self-assembly of zwitterionic meso-tetra(4-sulfonatophenyl)porphyrin (TPPS 4 ) molecules are studied through a combination of experimental and theoretical techniques. The interest in these systems, with diameters of 18 nm and lengths extending up to micrometers, derives from their strong interaction with light and their similarity to natural light-harvesting systems for photosynthesis. The absorption and linear dichroism spectra are obtained in the spectral region from 300 to 750 nm, which includes the exciton bands deriving from the molecular B (Soret) as well as the Q transitions. We demonstrate that a Frenkel exciton model which takes into account the four dominant molecular excited states (B x , B y , Q x , and Q y ) provides a good global fit to the experimental spectra. From comparison between theory and experiment, we propose a detailed molecular structure within the nanotube.

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Section: Introductionmentioning

confidence: 99%

Exciton Spectra and the Microscopic Structure of Self-Assembled Porphyrin Nanotubes

et al. 2009

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“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Examples of molecules that in solution self-assemble into aggregates of a tubular shape are carbocyanine molecules with hydrophobic and hydrophilic side groups [2][3][4][5][6][7] and porphyrin derivatives. [8][9][10][11][12] Both these molecules yield aggregates with a diameter of the order of 10 nm and a length of up to microns, which explains why they are often referred to as molecular nanotubes.…”

Section: Introductionmentioning

confidence: 99%

“…22 This perspective motivates many of the recent studies of the optical absorption and luminescence properties of the collective exciton states in these systems, as well as the energy transport and relaxation caused by these states. [2][3][4][5][6][7][23][24][25][26][27] In homogeneous cylindrical aggregates, the rotational symmetry around the axis imposes strong optical selection rules on the wave number k 2 that characterizes the exciton's Bloch wave function along a ring around the cylinder. In particular, it is easily shown that only states with k 2 = 0 and k 2 = ±1 may carry optical oscillator strength.…”

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Disorder-induced exciton localization and violation of optical selection rules in supramolecular nanotubes

Vlaming

Bloemsma

Nietiadi

et al. 2011

The Journal of Chemical Physics

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Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Using numerical simulations, we study the effect of disorder on the optical properties of cylindrical aggregates of molecules with strong excitation transfer interactions. The exciton states and the energy transport properties of such molecular nanotubes attract considerable interest for application in artificial light-harvesting systems and energy transport wires. In the absence of disorder, such nanotubes exhibit two optical absorption peaks, resulting from three super-radiant exciton states, one polarized along the axis of the cylinder, the other two (degenerate) polarized perpendicular to this axis. These selection rules, imposed by the cylindrical symmetry, break down in the presence of disorder in the molecular transition energies, due to the fact that the exciton states localize and no longer wrap completely around the tube. We show that the important parameter is the ratio of the exciton localization length and the tube's circumference. When this ratio decreases, the distribution of polarization angles of the exciton states changes from a two-peak structure (at zero and ninety degrees) to a single peak determined by the orientation of individual molecules within the tube. This is also reflected in a qualitative change of the absorption spectrum. The latter agrees with recent experimental findings. I. INTRODUCTIONDuring the past decade, there has been a growing interest in molecular J-aggregates of cylindrical geometry. 1-14 Examples of molecules that in solution self-assemble into aggregates of a tubular shape are carbocyanine molecules with hydrophobic and hydrophilic side groups 2-7 and porphyrin derivatives. [8][9][10][11][12] Both these molecules yield aggregates with a diameter of the order of 10 nm and a length of up to microns, which explains why they are often referred to as molecular nanotubes. Their shape and size resemble natural light-harvesting systems in green sulphur bacteria, 1, 13-18 while these systems also have a comparable geometry to previously studied helical polymers. [19][20][21] Because of this and the strong intermolecular excitation transfer interactions, these synthetic J-aggregates are considered excellent candidates for artificial light-harvesting systems. 22 This perspective motivates many of the recent studies of the optical absorption and luminescence properties of the collective exciton states in these systems, as well as the energy tran...

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“…An interesting example is the case of nanotubular carbocyanine J-aggregates that have recently been developed by Dähne and coworkers 29,30,31 and which have been suggested as building blocks for synthetic light-harvesting systems. These aggregates consist of two walls, which are only a few nanometers apart.…”

Section: Introductionmentioning

confidence: 99%

Excitation Energy Transfer between Closely Spaced Multichromophoric Systems: Effects of Band Mixing and Intraband Relaxation

2006

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We theoretically analyze the excitation energy transfer between two closely spaced linear molecular J-aggregates, whose excited states are Frenkel excitons. The aggregate with the higher (lower) exciton band edge energy is considered as the donor (acceptor). The celebrated theory of Förster resonance energy transfer (FRET), which relates the transfer rate to the overlap integral of optical spectra, fails in this situation. We point out that in addition to the well-known fact that the pointdipole approximation breaks down (enabling energy transfer between optically forbidden states), also the perturbative treatment of the electronic interactions between donor and acceptor system, which underlies the Förster approach, in general loses its validity due to overlap of the exciton bands. We therefore propose a nonperturbative method, in which donor and acceptor bands are mixed and the energy transfer is described in terms of a phonon-assisted energy relaxation process between the two new (renormalized) bands. The validity of the conventional perturbative approach is investigated by comparing to the nonperturbative one; in general this validity improves for lower temperature and larger distances (weaker interactions) between the aggregates. We also demonstrate that the interference between intraband relaxation and energy transfer renders the proper definition of the transfer rate and its evaluation from experiment a complicated issue, which involves the initial excitation condition.

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Surfactant-Induced Changes of Morphology of J-Aggregates: Superhelix-to-Tubule Transformation

Cited by 97 publications

References 41 publications

Exciton Spectra and the Microscopic Structure of Self-Assembled Porphyrin Nanotubes

Exciton Spectra and the Microscopic Structure of Self-Assembled Porphyrin Nanotubes

Disorder-induced exciton localization and violation of optical selection rules in supramolecular nanotubes

Excitation Energy Transfer between Closely Spaced Multichromophoric Systems: Effects of Band Mixing and Intraband Relaxation

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