Structure determination and electrochemistry of products from the radical reaction of C-60 with azo(bisisobutyronitrile)

Thermal decomposition of azo(bisisobutyronitrile) in a 1,2-dichlorobenzene solution of C-60 gave three regioisomeric 1,x-di(2-cyano-2-propyl)-1,x-dihy dro[60]fullerenes in 12, 2, and 4% yields, assigned as the 1,4-, 1,2-, and a third isomer of still uncertain structure. The 1,4- and unidentified isom ers underwent three reversible reduction steps by cyclic voltammetry, and U V-vis-NIR spectra of the mono- and dianions generated electrochemically wer e recorded. The first two redox potentials of the 1,4-isomer were the same as those of C-60, but those of the third isomer were positively shifted by 0.23 and 0.21 V from those of C-60, showing that it is an electron-deficien t derivative of C-60.