Synthesis and characterisation of C60 derivatives containing functionalised anthraquinone groups and an unusual fullerene-stabilised cation

Bidell W, Compton RG, Eklund JC, Green MLH, Rebbitt TO, Stephens AHH

The ortho-anthraquinonedimethane dienophiles prepared in situ from 1,4-dihydroxy-2,3-bis(bromomethyl)-anthraquinone and 1,4-dimethoxy-2,3-bis(bromomethyl)anthraquinone respectively react with the fullerene C60 to give the anthraquinone derivatives: dihydroxy-anthraquinone-C60 and dimethoxy-anthraquinone-C60. The former compound with sodium butoxide and 15-crown-5 gives the bis(sodium-15-crown-5)dioxo-anthraquinone-C60. The dimethoxy-anthraquinone-C60 reacts with [Ru(PPh3)2(NO)Cl] to form the bis-adduct {[η2-(dimethoxy-anthraquinone-C60)][Ru(PPh3 )2(NO)Cl]}. The electrochemistry of the dihydroxy- and dimethoxy-anthraquinone-C60 derivatives has been studied by cyclic voltammetry and, in contrast to 1,4-dihydroxy-2,3-dimethylanthraquinone, the compound dihydroxy-anthraquinone-C60 shows two separate one electron oxidations at lower potentials strongly suggesting a relatively rare example of a fullerene stablised cation.