Optical spectra and localization of excitons in inhomogeneous helical cylindrical aggregates

Didraga, C.; Knoester, Jasper

doi:10.1063/1.1807825

Cited by 56 publications

(87 citation statements)

References 60 publications

(126 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…37,51 Once the self-energy Σ(ω) has been calculated, 55 the spectra follow directly from eq 13 with the denominator replacement mentioned above and the oscillator and dichroism strength given in the Appendix.…”

Section: A(ω)mentioning

confidence: 99%

“…6,37 In this model, the molecular arrangement in the tubular structure is thought of as originating from a planar aggregate wrapped onto a cylindrical surface in a seamless way. A Frenkel exciton model, which accounts for the resonant dipole-dipole interactions between the various molecules in the aggregate, is then used to describe the relevant collective excited states.…”

Section: Modelmentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2009

View full text Add to dashboard Cite

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.

show abstract

Section: A(ω)mentioning

confidence: 99%

Section: Modelmentioning

confidence: 99%

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

et al. 2009

View full text Add to dashboard Cite

show abstract

“…For the cylindrical aggregates, N coh has previously been defined in Ref. 35 as the total number of molecules n with C q ( n) > 1/e. Here we will not use that definition of N coh , but rather define it as proposed in Ref.…”

Section: Characterizing Exciton States In Disordered Cylindersmentioning

confidence: 99%

“…For all three cases, it is possible to explicitly evaluate the orientational averages in Eq. (6), 1,35 …”

Section: B Absorption Spectramentioning

confidence: 99%

“…II C, the presence of disorder induces localization of the exciton states. To quantify this behavior, a number of different measures exist, 27,33,35,[40][41][42][43][44] each giving an estimate of the number of molecules that coherently participate in a given exciton state. We will consider here the autocorrelation function of the exciton wave function, 35,[42][43][44] which is particularly useful to probe not only the size but also the directionality of the localization on the cylinder surface.…”

Section: Characterizing Exciton States In Disordered Cylindersmentioning

confidence: 99%

See 1 more Smart Citation

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

Vlaming

Bloemsma

Nietiadi

et al. 2011

The Journal of Chemical Physics

View full text Add to dashboard Cite

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...

show abstract

Coexistence of free and self‐trapped excitons in disordered J‐aggregates

Malyukin

2006

Phys. Status Solidi (c)

View full text Add to dashboard Cite

PACS 71.35.AaCoexistence of free and self-trapped exciton in amphi-PIC J-aggregates is proved by the numerous experimental data presented and analyzed. The self-trapping states are shown to originate from delocalized exciton states exhibiting collective nature of polaronic relaxation. The strong correlation between the efficiency of exciton self-trapping and static disorder degree in J-aggregates has been shown. In amphi-PIC J-aggregates the polaronic state formation found out to require the overcoming an energy barrier which appears for quasi-one-dimension system as a result of combination of one-dimensional exciton motion and three-dimension lattice deformation. [16,17]. Despite relatively long history of J-aggregate investigation, some questions concerning exciton dynamics governed by polaronic relaxation are not fully understood.In many cases the absorption and luminescence properties of J-aggregates are well described within the one-dimensional Frenkel exciton model for a rigid chain with static disorder [1][2][3][4][5][6]. But, the chain could be deformable and if the constant of exciton-lattice coupling is strong enough, the exciton can create a chain distortion that produces a new polaronic state below the exciton band bottom. This phenomenon is called self-trapping [18]. The self-trapping pattern of the exciton interacting with a lattice via short-range potential depends strongly on the exciton motion dimension [19][20][21]. According to the Rashba-Toyozava theory, the excitons characterized by one-dimensional motion are always self-trapped. So, free excitons are unstable irrespective of the magnitude of exciton-lattice coupling and there is no any energy barrier which separates free and self-trapped exciton states [18][19][20][21]. The spatial extension of

show abstract

Optical spectra and localization of excitons in inhomogeneous helical cylindrical aggregates

Cited by 56 publications

References 60 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

Coexistence of free and self‐trapped excitons in disordered J‐aggregates

Contact Info

Product

Resources

About