Utilizing redox-chemistry to elucidate the nature of exciton transitions in supramolecular dye nanot

Abstract

Supramolecular assemblies that interact with light have recently garnered much interest as well-defined nanoscale materials for electronic excitation energy collection and transport. However, to control such complex systems it is essential to understand how their various parts interact and whether these interactions result in coherently shared excited states (excitons) or in diffusive energy transport between them. Here, we address this by studying a model system consisting of two concentric cylindrical dye aggregates in a light-harvesting nanotube. Through selective chemistry we are able to unambiguously determine the supramolecular origin of the observed excitonic transitions. These results required the development of a new theoretical model of the supramolecular structure of the assembly. Our results demonstrate that the two cylinders of the nanotube have distinct spectral responses and are best described as two separate, weakly coupled excitonic systems. Understanding such interactions is critical to the control of energy transfer on a molecular scale, a goal in various applications ranging from artificial photosynthesis to molecular electronics. The collective excited states (excitons) in supramolecular light-harvesting systems depend intimately on their structure and it is crucial to understand how these states interact. Now it is shown that simple redox chemistry can be used to address this fundamental question by simplifying the complex excitonic interactions in such multichromophoric systems.

Cite this article

Eisele, D., Cone, C., Bloemsma, E. et al. Utilizing redox-chemistry to elucidate the nature of exciton transitions in supramolecular dye nanotubes. Nature Chem 4, 655–662 (2012). https://doi.org/10.1038/nchem.1380

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