Uniform exciton fluorescence from individual molecular nanotubes immobilized on solid substrates

Abstract

Uniform exciton fluorescence from individual molecular nanotubes immobilized on solid substrates Eisele, Doerthe M.; Knoester, Jasper; Kirstein, Stefan; Rabe, Juergen P.; Vanden Bout, David A.; Rabe, Jürgen P. 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. Since the optical properties of the tubular J-aggregates strongly depend on their specific supramolecular structure, the absorption and emission spectra from the sample can be used to determine if the molecular structure of the aggregates has changed upon deposition onto the substrate. Because the tubules on the substrate are highly dilute, emission spectra rather than the very weak absorption spectra were used. Emission spectra were collected rather than excitation spectra because of the extremely small Stokes shift for the emission. Emission spectra of tubular J-aggregates in solution (red) and after preparation on a quartz surface (black)via spin-coating and slowly drying in air (c) Idem, but now the black line is the spectrum of aggregates prepared on quartz via the drop flow technique and drying by blowing with nitrogen.As shown in the manuscript, the sample prepared by the drop-flow technique and carefully dried in air in a black box had spectra that were nearly identical in both position and width to the solution, indicating no significant morphological and structural changes upon deposition.3

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

“…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.…”

“…[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.…”

“…Recent experimental work has demonstrated that indeed the idealized selection rules are an oversimplified view of reality, in particular, in cylinders with a wider circumference. 32 Furthermore, it has also been demonstrated that by scanning near-field optical microscopy the polarization dependent luminescence of segments of individual nanotubes may be investigated, 7 which opens the perspective to look into the optical selection rules and the polarization of exciton states in much more detail.…”

Room-Temperature Micron-Scale Exciton Migration in a Stabilized Emissive Molecular Aggregate

“…In a water−methanol mixture, C8S3 monomers self-assemble into nanotubes with an outer wall diameter of ∼12.5 nm, an inner wall diameter of ∼6 nm, and longitudinal dimensions tens of micrometers in length (panels b and d of Figure 1). 13,16 To accomplish our study, we have developed a method to stabilize C8S3 LHNs against light-induced and cryogenic damage in a sugar-based matrix. 19 We modify the normal preparation by diluting the aggregate preparation in a highly concentrated sucrose−trehalose solution and drying overnight to create a concentrated, clear, dry, sugar-glass matrix ( Figure 1c).…”

Templated J-Aggregate Nanotubes for the Detection of Dopamine

“…J-aggregate nanotubes are attractive for efficient electron transfers because they share the molecular packing feature with photosynthetic light-harvesting antennas [19]- [24]. In this paper, we report the formation of templated J-aggregate nanotubes by the adsorption of 3,3'-diethylthiacarbocyanine iodide (DTCC) on the self-assembled nanotubes of lithocholic acid (LCA).…”