Dimethyl azo(bisisobutyrate) and C-60 produce 1,4-and 1,16-di(2-carbomethoxy-2-propyl)-1,x-dihydro[60]fullerenes

Thermal decomposition of dimethyl azo(bisisobutyrate) in a solution contain ing C-60 produced 1,4- and 1,16-di(2-carbomethoxy-2-propyl)-1,x-dihydro[60] fullerenes in yields of 21% and 27%, respectively, based on reacted C-60 Th e structure of this first 1,16-dialkyl-1,16-dihydro[60]fullerene was assign ed from C-13 2D INADEQUATE NMR spectra. The 1,16-isomer has first and secon d electrochemical reduction potentials shifted positively by 0.18 V relativ e to those of the 1,4-isomer. From the dose similarity of all spectral, chr omatographic, and electrochemical data, the previously unassigned isomer of 1,x-di(2-cyano-2-propyl)-1,x-dihydro[60]fullerene which was obtained from azo(bisisobutyronitrile) and C-60, is also a 1,16-isomer.