C₆₀O₃, a Fullerene Ozonide:  Synthesis and Dissociation to C₆₀O and O₂

An unstable intermediate has been detected and isolated in the reaction of ozone with C60 in solution. On the basis of its UV−vis absorption spectrum, the measured release of O2 in its decay to the epoxide C60O, and the first-order kinetics of this reaction, the intermediate has been identified as C60O3, a primary ozonide. This [6,6]-closed adduct of ozone with C60 thermally dissociates to C60O plus O2 in toluene solution, octane solution, and the solid phase with rate constants (at 23 °C) of 4.6 × 10-2, 1.3 × 10-3, and 3.0 × 10-3 min-1, respectively. The activation energy for dissociation in toluene solution is approximately 89 kJ mol-1. Semiempirical quantum calculations indicate that the formation and subsequent dissociation of C60O3 are both exothermic processes. These findings constitute the first observation of a fullerene ozonide.