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Updated: Dec 25, 2025

Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems
Published on: April 28, 2016
The Structural Origins of Intense Circular Dichroism in a Waggling Helicene Nanoribbon
Nathaniel J Schuster, Leo A Joyce1, Daniel W Paley
1Department of Process Research and Development, Merck and Co., Inc., Rahway, New Jersey 07065, United States.
Abstract:
We report the synthesis of a new perylene-diimide-based helical nanoribbon, which exhibits the largest molar electronic circular dichroism in the visible range of any molecule. This nanoribbon also displays a substantial increase in molar circular dichroism relative to a smaller helical analogue, even though they share a similar structure: both nanoribbons incorporate two conformationally dynamic double-[4]helicene termini and a rigid [6]helicene-based core within their helical superstructures. Using DFT and TDDFT calculations, we find that the double-[4]helicenes within both nanoribbons orient similarly in solution; as such, conformational differences do not account for the disparities in circular dichroism. Instead, our results implicate the configuration of the double-[6]helicene within the larger nanoribbon as the source of the observed chiroptical amplification.
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