A collaboration between Oxford Chemistry and IBM Research Europe – Zurich has achieved the synthesis and characterisation of the first odd-numbered cyclocarbon, C13. The study is published this week in Science.
Left: Reaction used to synthesise cyclo[13]carbon. Right: AFM images of molecules of cyclo[13]carbon adsorbed on NaCl. (From Science article.)
- Cyclo[13]carbon was synthesised from decachlorofluorene (C13Cl10) on a NaCl monolayer, deposited on a gold Au(111) substrate, at 5 K.
- The reaction was promoted by applying voltage pulses from the scanning probe tip, and appears to occur via retro-Bergman rearrangement of benzyne intermediates.
- C13 has an open-shell triplet ground state and a delocalised carbene centre.
- Atomic force microscopy (AFM) reveals that molecules of C13 have a kinked geometry, which shows different extents of distortion and carbene localization, depending on the molecular environment.
- Dehalogenation of two proximate precursor molecules was found to generate cyclo[26]carbon, probably via dimerization of C13.
You can read more about this study in Science. https://doi.org/10.1126/science.ado1399