An unstable intermediate has been detected and isolated in the reaction of
ozone with C-60 in solution. On the basis of its UV-vis absorption spectrum
, the measured release of O-2 in its decay to the epoxide C60O, and the fir
st-order kinetics of this reaction, the intermediate has been identified as
C60O3, a primary ozonide. This [6,6]-closed adduct of ozone with C-60 ther
mally dissociates to C60O plus O-2 in toluene solution, octane solution, an
d the solid phase with rate constants (at 23 degreesC) of 4.6 x 10(-2), 1.3
x 10(-3): and 3.0 x 10(-3) min(-1), respectively. The activation energy fo
r dissociation in toluene solution is approximately 89 kJ mol(-1) Semiempir
ical quantum calculations indicate that the formation and subsequent dissoc
iation of C60O3 are both exothermic processes. These findings constitute th
e first observation of a fullerene ozonide.