Neutral Möbius [5]helicene-embedded Cycloparaphenylene Nanohoops: Synthesis, [4n]Möbius Topology and Hückel Aromaticity

29 January 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The relationship between Möbius topology and aromaticity and topological chirality is still elusive to date, which is, to a large extent, due to the related synthetic challenges and, further, the scarcity in both the quantity and the diversity of the con-structed Möbius systems. In this work, we reported the synthesis of [4n]Möbius conjugated all-carbon nanohoops ([5]H-[7,8]CPPs) by utilizing a [5]helicene unit as a hidden writhe and a masked aromatic unit to overcome the strain inherited from Möbius topology. X-ray analysis revealed that [5]H-[7,8]CPPs contain a [5]helicene moiety and an oligoparaphenylene unit, and display a Möbius topology. Photophysical investigations demonstrated that [5]H-[7,8]CPPs exhibited moderately high fluorescence quantum yields, which are significantly higher than those of pristine [5]helicene and [7,8]CPPs. Chiropti-cal studies revealed that [5]H-[7,8]CPPs displayed an obvious Cotton effect in circular dichroism and bright circularly polar-ized luminescence, indicating that the chirality of [5]helicene was efficiently transferred to the overall carbon nanohoops. Importantly, theoretical investigations reveal that, though possessing a 4n π-electron array, such all-carbon nanohoops are fully conjugated systems with Hückel aromaticity. The results may help us to better understand the relationship between Möbius topology and aromaticity.


Möbius topology
circularly polarized luminescence

Supplementary materials

Supporting Information of Neutral Möbius [5]helicene-embedded Cycloparaphenylene Nanohoops: Synthesis, [4n]Möbius Topology and Hückel Aromaticity
This supporting Information is the detail of synthesis, crystallography and related property.


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.