Chemistry:Octafluorocubane
Octafluorocubane or perfluorocubane is an organofluorine compound with the formula C
8F
8, consisting of eight carbon atoms joined into a cube, with a fluorine bonded to each carbon corner. It is a colorless, sublimable solid at room temperature. It has been of longstanding theoretical interest, but was not synthesised until 2022, when it was prepared in several steps from the 1,1,1,2,2,4,5,5,5-Nonafluoro-4-(trifluoromethyl)-3-pentanol ({{{2}}}) ester of carboxycubane, beginning with its heptafluorination. According to X-ray crystallography, the C–C distances (1.570 Å) in octafluorocubane are consistent in length with those in the parent cubane (1.572 Å).[1]
Octafluorocubane has attracted interest from theorists because of its unusual electronic structure,[2] which is indicated by its susceptibility to undergo reduction at −2.1 V to a detectable (though unstable) anion C
8F−
8, with the free electron trapped inside of the cube.[3]
Octafluorocubane crystals exhibit intermolecular σ-hole interactions between fluorine atoms and neighboring cyclobutane ring centers. The molecule is predicted to be a strong tetrel bond donor.[1]
It was voted "favorite molecule of 2022" by readers of Chemical & Engineering News.[4]
References
- ↑ 1.0 1.1 "Electron in a cube: Synthesis and characterization of perfluorocubane as an electron acceptor". Science 377 (6607): 756–759. August 2022. doi:10.1126/science.abq0516. PMID 35951682. Bibcode: 2022Sci...377..756S.
- ↑ Pichierri, Fabio (September 2017). "Substituent effects in cubane and hypercubane: a DFT and QTAIM study". Theoretical Chemistry Accounts 136 (9). doi:10.1007/s00214-017-2144-5.
- ↑ "Perfluorocubane-a tiny electron guzzler". Science 377 (6607): 709. August 2022. doi:10.1126/science.adc9195. PMID 35951708. Bibcode: 2022Sci...377..709K. https://hal.science/hal-03873082v1/file/Krafft.Riess.22_Perspective%20on%20perfluorocubane.pdf.
- ↑ "A cube catches an electron". Chemical & Engineering News. December 2022. ISSN 1520-605X. https://cen.acs.org/education/science-communication/CENs-Year-Chemistry-2022/100/i44. Retrieved 2022-12-30.
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