Kinetically Controlled Near-Equatorial Alkylation of Cs-C70(CF3)8 Dianions

The electrophilic alkylation of dianions of fullerene derivatives generated by deprotonation of the corresponding dihydrides is described, using the example of the regioselective synthesis of a trifunctional derivative C-70(CF3)(8)(CH3)H with a near-equatorial location of all addends. The structure of the first synthesized compound is established by means of mass spectrometry and one- and two-dimensional NMR correlation spectroscopy. The reasons for the high regioselectivity of the formation of the single isomer C-70(CF3)(8)(CH3)H are explained using quantum chemical calculations at the level of density functional theory for isomers of anionic intermediates and the product. Electron absorption and fluorescence spectroscopy are used to demonstrate the fundamental effect of the near-equatorial location of addends in the C-70(CF3)(8)(CH3)H compound on its optical and fluorescent properties.