Electrogeneration and characterization of a (C_6H_5CH_2)_2C_(70) mixture

摘要

(C_6H_5CH_2)_2C_(70) was obtained by a reaction between electrogenerated C_(70)~2- and C_6H_5CH_2Br in PhCN, 0.2 M TBAP and purified by HPLC. Negative MALDI analysis of (C_6H_5CH_2)_2C_(70) reveals the presence of the molecular ion, thus confirming formation of the compound. The ~1H NMR spectrum of (C_6H_5CH_2)_2C_(70) exhibits two AB quartets at 2.91 and 3.63 ppm with different intensities and one singlet at 3.35 ppm. The presence of two AB quartets with different intensities is consistent with two structures where benzyl groups are bonded to the chiral sp~3 carbons of C_(70), while the presence of a singlet is consistent with another structure where the benzyl groups are bonded to the non-chiral sp~3 carbons of C_(70). The overall NMR data suggest the presence of three non-separable isomers. The (C_6H_5CH_2)_2C_(70) mixture was also characterized by cyclic voltammetry (CV) in PhCN containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) and the monoanion was characterized by visible and near-IR spectroscopy after bulk electrogeneration.