Kinetics of the Diels–Alder reaction between C60 and acenes

The kinetics of the Diels–Alder reactions between C60 and the linear acenes anthracene and tetracene are studied in toluene, in the temperature range 22–63 °C. It is observed that tetracene reacts much more readily with C60 than does anthracene. The different reactivities of anthracene and tetracene towards C60 correlate with the respective aromaticity loss upon cycloaddition, as previously predicted theoretically. The two monoadducts also display different kinetics as regards the dissociation back to the reagents. In the studied temperature range, tetracene monoadduct decomposition by retro-Diels–Alder reaction is negligible, while the anthracene monoadduct is unstable above room temperature.