Near-Atomic Resolution Structure of J-aggregated Helical Light Harvesting Nanotubes

05 October 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Function-oriented design of supramolecular self-assemblies represents a foundational goal in chemistry. Especially, chromophore self-assemblies display extreme photophysical changes from their monomers that are sensitive to the nanoscale molecular arrangements. Slip-stacked arrangements in J-aggregates lead to red shifts (>200 nm) and enhanced quantum yields. Actively introducing specific molecular arrangements using supramolecular chemistry provides a platform to tune the excitonic couplings and avail exotic photophysical properties. However, the nanoscale molecular arrangements have not yet been directly observed in these solution-state assemblies. Here, we present a high-resolution structure of the prototypical biomimetic light harvesting nanotubes (LHNs) of an amphiphilic cyanine dye (C8S3-Cl). We achieve a 3.3 Å resolution with helical reconstruction of cryo-EM images, directly visualizing the atomic scale parameters and packing arrangements that control the excitonic properties. Our structure clearly shows a brick layer arrangement of the molecules as opposed to the previously thought herringbone arrangement. Furthermore, we identify a new non-biological supramolecular motif – interlocking sulfonates, that may be responsible for the slip-stacked packing and ultimately the J-aggregate nature of LHNs. This motif may be relevant towards other amphiphilic self-assemblies, in general and provides a new chemical handle on predictable self-assemblies.


Light Harvesting Nanotubes
Molecular Aggregates
Cryo-EM structure
Frenkel excitons

Supplementary materials

Supplementary Information
Dimerized Frenkel exciton model, geometric model for C8S3-Br, and synthesis of C8S4-Cl.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.