Matrix isolation of fullerene-derived CO2 at ambient temperature

Heating fullerene oxides, e.g. C120O, C70O, C60O and C60O2, in a KBr matrix at 225°C under 0.2 mbar vacuum, produces a sharp IR band at 2330 cm−1 due to matrix-isolated CO2. The band is also obtained by heating a KBr matrix of the insoluble deposits that fullerenes form on standing in air. The matrices are extremely stable and are unchanged even by prolonged heating at 225°C under vacuum. Heating a KBr matrix of the deposit from C84 produces also a sharp stable band at 2035 cm−1 consistent with matrix-isolated C3. Similar treatment of C70F38O produces matrices containing both CO2 and CO, the latter being of lower stability.