The higher fullerenes: Isolation and characterization of C₇₆, C₈₄, C₉₀, C₉₄, and C₇₀O, an oxide of D_5h-C₇₀

The toluene extract of the fluffy carbon material produced by resistive heating of graphite contains a variety of molecules larger than C₆₀ and C₇₀ in a total amount of 3 to 4% by weight. Repeated chromatography of this material on neutral alumina has led to the isolation of stable solid samples of C₇₆, C₈₄, C₉₀, and C₉₄. The characterization, which includes mass spectrometry, ¹³C nuclear magnetic resonance, electronic absorption (ultraviolet/visible) and vibrational (infrared) spectroscopy identifies these all-carbon molecules as higher fullerenes. In addition, C₇₀O, a stable oxide, has been isolated that is structurally and electronically closely related to D_5h-C₇₀. This compound forms during the resistive heating process and probably has an oxygen atom inserted between two carbon atoms on the convex external surface of the C₇₀ skeleton.