An unprecedented cationic supramolecule [(Cp '' Fe(eta(5)-P-5))(12){CuNCMe}(8)](8+) 2.66 nm in diameter was selectively isolated as a salt of the weakly coordinating anion [Al{OC(CF3)(3)}(4)](-) for the first time and characterized by X-ray structure analysis, PXRD, NMR spectroscopy, and mass spectrometry. Its metal-deficient core contains the lowest possible number of Cu atoms to connect 12 pentaphosphaferrocene units, providing a supramolecule with fullerene topology which, topologically, also represents the simplest homologue in the family of metal-deficient pentaphosphaferrocene-based supramolecules [{Cp(R)Fe(eta(5)-P-5)}(12)(CuX)(20-n)]. The 12 vacant metal sites between the cyclo-P-5 rings, the largest number attained to date, make this compound a facile precursor for potential inner and outer modifications of the core as well as for functionalization via the substitution of labile acetonitrile ligands.