Synthesis of two pentaarylated [60]fullerene derivatives Ar5C60-H (Ar = p-MeC6H4, m-MeC6H4) and their novel electrochemical properties

Through one pot reaction of C-60 with organocopper/magnesium reagent ( p-Me C6H4)(2) CuMgBr or (m-MeC6H4)(2-)CuMgBr prepared from CuBr . Me2S and p-MeC 6H4MgBr or m-MeC6H4MgBr and subsequent quenching with aqueous NH4Cl, two pe ntaarylated [60] fullerene derivatives (p-MeC6H4)(5)C60H (1) and (m-MeC6H4) (5)C60H (2) have been synthesized in 94% and 96% yields, respectively. Whil e known compound 1 prepared via this improved method is unambiguously ident ified, new compound 2 is fully characterized by elemental analysis, IR, UV- vis, H-1 NMR and C-13 NMR spectroscopies. Additionally, electrochemical stu dy shows that the two [60] fullerene derivatives I and 2 in dichloromethane solution display two sequential one-electron reductions which are shifted by about 0.4 V towards more negative potential values with respect to free C-60. such remarkable cathodic shift is attributed to the multiple breakage of the double-bond conjugation within the fullerene core.