The former "C60F16" is actually a double-caged adduct: (C60F16)(C60)

Chem Commun (Camb). 2007 Feb 21:(7):704-6. doi: 10.1039/b615457c. Epub 2006 Dec 6.

Abstract

X-ray diffraction study of the substance originally believed to be C(60)F(16) reveals a double-caged structure, (C(60)F(16))(C(60)); MALDI mass spectra, 19F NMR spectral data and reasons for stability are discussed.