Materials Chemistry

Tubular J-aggregates of cyanine dyes in the near-infrared



Developing improved organic infrared emitters has wide-ranging applicability in fields such as bioimaging or energy harvesting. We synthesize redshifted analogues of C8S3, a well-known cyanine dye that self assembles into tubular aggregates which have attracted widespread attention as artificial photosynthetic complexes. Despite the elongated dye structure, the new pentamethine dyes retain their tubular self-assembly and emit at near-infrared wavelengths. Cryo-electron microscopy and detailed photophysical characterization of the new aggregates reveal similar absorption lineshapes with ~100 nm of redshift, as well as supramolecular morphologies that resemble their trimethine counterparts; the pentamethine aggregates generally show more disorder and decreased superradiance, suggesting that more ordered structures yield more robust photophysical properties. These results provide design principles of superradiant organic emitters, expand the chemical space of near-infrared aggregates, and introduce two additional wavelength-specific antennae as model systems for study.

Version notes

Changed figures/figure order to increase clarity of narrative as well as enlarge cryo-EM work.


Thumbnail image of NIR_C8S3_rxiv2.pdf

Supplementary material

Thumbnail image of NIR_C8S3_SI_v7.pdf
Supporting Information for Tubular J-aggregates of cyanine dyes in the near-infrared
Synthesis and photophysical characterization details.