Octafluorocubane

Octafluorocubane
Names
	IUPAC name 1,2,3,4,5,6,7,8-octafluorocubane
	Other names perfluorocubane
Identifiers
CAS Number	623570-55-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	20578010;
PubChem CID	16746787;
CompTox Dashboard (EPA)	DTXSID901171772 ;
	InChI InChI=1S/C8F8/c9-1-2(10)5(13)3(1,11)7(15)4(1,12)6(2,14)8(5,7)16 Key: DLEOOIAXKVODBG-UHFFFAOYSA-N;
	SMILES C12(C3(C4(C1(C5(C2(C3(C45F)F)F)F)F)F)F)F;
Properties
Chemical formula	C8F8
Molar mass	248.075 g·mol−1
Appearance	colorless, sublimable
Density	2.429 g/cm3
Melting point	160.1–171.1 °C (320.2–340.0 °F; 433.2–444.2 K)
Related compounds
Related compounds	Octanitrocubane
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Octafluorocubane or perfluorocubane is an organofluorine compound with the formula C₈F₈, 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 (CF₃)₂CFCH(OH)C₂F₅ ester of carboxy cubane, 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 C₈F−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

^ ^a ^b Sugiyama M, Akiyama M, Yonezawa Y, Komaguchi K, Higashi M, Nozaki K, Okazoe T (August 2022). "Electron in a cube: Synthesis and characterization of perfluorocubane as an electron acceptor". Science. 377 (6607): 756–759. Bibcode:2022Sci...377..756S. doi:10.1126/science.abq0516. PMID 35951682. S2CID 251515925.
^ 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.
^ Krafft MP, Riess JG (August 2022). "Perfluorocubane-a tiny electron guzzler" (PDF). Science. 377 (6607): 709. Bibcode:2022Sci...377..709K. doi:10.1126/science.adc9195. PMID 35951708. S2CID 251517529.
^ Boerner, Leigh Krietsch (December 2022). "A cube catches an electron". Chemical & Engineering News. ISSN 1520-605X. Archived from the original on 26 February 2026. Retrieved 2022-12-30.

[Sugiyama2022-1] Sugiyama M, Akiyama M, Yonezawa Y, Komaguchi K, Higashi M, Nozaki K, Okazoe T (August 2022). "Electron in a cube: Synthesis and characterization of perfluorocubane as an electron acceptor". Science. 377 (6607): 756–759. Bibcode:2022Sci...377..756S. doi:10.1126/science.abq0516. PMID 35951682. S2CID 251515925.

[2] 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.

[3] Krafft MP, Riess JG (August 2022). "Perfluorocubane-a tiny electron guzzler" (PDF). Science. 377 (6607): 709. Bibcode:2022Sci...377..709K. doi:10.1126/science.adc9195. PMID 35951708. S2CID 251517529.

[4] Boerner, Leigh Krietsch (December 2022). "A cube catches an electron". Chemical & Engineering News. ISSN 1520-605X. Archived from the original on 26 February 2026. Retrieved 2022-12-30.

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