[60]Fullerene adducts with 9-substituted anthracenes: mechanochemical preparation and retro Diels–Alder reaction

Three 9-substituted anthracene derivatives, that is, 9-hydroxymethylanthracene (), 9-methoxymethylanthracene () and bis(9-anthrylmethyl) adipate (), were chosen as the model compounds to evaluate the reactivity in their Diels–Alder reactions with [60]fullerene and in retro Diels–Alder reactions of the formed cycloadducts. Corresponding adducts , and were prepared in high yields under solvent-free conditions using high-speed vibration milling technique. In order to determine thermal stabilities of adducts , and , their dissociations in the temperature range of 40–65 °C were investigated. Fitting the dissociation rates and temperatures to the Arrhenius equation gives the activation energies of 25.8, 21.8 and 24.9 kcal/mol for compounds , and , respectively.