Synthesis of the singly bonded fullerene dimer C120H2 and the difullerenylacetylene C122H2, and generation of the all-carbon dianion C1222–

Abstract

1,1′,2,2′-Tetrahydrobi[60]fulleren-1-yl C₁₂₀H₂ (9) and bis(1,2-dihydro[60]fulleren-1-yl)acetylene C₁₂₂H₂ (11) were prepared, and their structures were determined based on ¹H and ¹³C NMR, MS, and UV–VIS spectroscopies. While the deprotonation of C₁₂₀H₂ with t-BuOK caused dissociation and resulted in the formation of the radical anion C₆₀^˙–, the generation of dianion C₁₂₂^2– (12^2–) from C₁₂₂H₂ (11) was confirmed by visible–near-IR and ¹³C NMR spectroscopies. The electrochemical studies indicated that dianion C₁₂₂^2– (12^2–) was formed also during the reduction process of C₁₂₂H₂ (11). The oxidation process of the dianion 12^2– was found to be irreversible suggesting that the radical species produced undergoes rapid coupling.