Extraction, Isolation, and Characterization of Fullerene C60: A Safe and Reliable Separation Experiment

The recent discovery (1) and characterization (2, 3) of the pure-carbon, soccer ball-shaped molecule buckminsterfullerene-C₆₀ has spawned intensive research (4). Now a favorite study topic of physical and organic chemists, fullerene chemistry has instilled in scientists a variety of application hopes. Although development is slow, many envision a future of fullerene superconductors, large-scale industrial catalysts, and perhaps even antiviral agents (5). This academic interest and enthusiasm in fullerene science has prompted us to develop a safe, inexpensive, and practical undergraduate activity for the study of C₆₀, the most popular member of the fullerene family.

Appropriate for an advanced high school or introductory college chemistry laboratory, the experiment described here allows students to safely perform organic chemistry techniques in the absence of a fume hood. The methods we employ are modifications of those described by Ajie (3), Scrivens (6) and Marecek (7). Owing to the nonpolar nature of fullerene molecules, light-viscosity mineral oil is a suitable solvent for recovery of small quantities of C₆₀. Nontoxic and relatively unreactive, mineral oil has the added benefit of not vaporizing at room temperature, unlike typical organic solvents. While no material safety data sheet (MSDS) is currently available for fullerene soot and its properties have not been fully investigated, recent studies involving topical application of fullerene extracts to mouse skin have shown no tumor-promoting activity in either acute or subchronic exposure (8). In this activity, students solubilize and extract fullerenes (predominantly C₆₀ and C₇₀) from fullerene soot and chromatographically separate C₆₀ molecules from the resulting mixture. The C₆₀ product may then be characterized spectrophotometrically.