Loops of interconnected benzene rings have long fascinated chemists, who have now developed a more flexible way to string the rings together.
Kenichiro Itami and his co-workers at Nagoya University in Japan created the loop, or cycloparaphenylene (CPP, pictured below left), by first coupling L-shaped and linear molecules to form U-shaped ones. They then combined two of these molecules to form the desired O-shaped CPP.
This modular approach has potential for producing specific CPPs of any size greater than 13 benzene rings. The loops could be useful for fabricating single-walled carbon nanotubes of specific diameter, by growing the loops horizontally (pictured right).

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Chemistry: Ring-a-ring o'benzene. Nature 468, 735 (2010). https://doi.org/10.1038/468735c
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DOI: https://doi.org/10.1038/468735c