Gold heptafluoride is a gold(V) compound with the empirical formula AuF7. The synthesis of this compound from gold pentafluoride and a monatomic fluorine plasma was first reported in 1986. However, current calculations suggest that the structure of the synthesized molecule was actually a difluorine ligand on a gold pentafluoride core, AuF5·F2. That would make it the first difluorine complex and the first compound containing a fluorine atom with an oxidation state of zero. The gold(V)–difluorine complex is calculated to be 205 kJ/mol more stable than "true" gold(VII) fluoride. The vibrational frequency at 734 cm−1 is the hallmark of the end-on coordinated difluorine molecule.
References
Timakov, A. A.; Prusakov, V. N.; Drobyshevskii, Y. V. (1986). "Gold heptafluoride" (PDF). Dokl. Akad. Nauk SSSR (in Russian). 291: 125–128. Archived from the original (PDF) on 30 June 2022. Retrieved 3 July 2022. https://web.archive.org/web/20220630183514/http://www.tashbook.com/gold/Timakov%20et%20al%201985.pdf ↩
Himmel, Daniel; Riedel, Sebastian (2007-05-31). "After 20 Years, Theoretical Evidence That "AuF7" Is Actually AuF5·F2". Inorganic Chemistry. 46 (13): 5338–5342. doi:10.1021/ic700431s. PMID 17511450. /wiki/Doi_(identifier) ↩