Reductive electrochemistry of spiromethanofullerenes.
The synthesis and electrochemical properties of spiromethanofullerenes 1-6 are described. The syntheses were achieved via the diazomethane route, and the regioisomeric distribution of bis-adducts 3 was determined by (1)H NMR, UV-vis, and HPLC analysis. The electrochemistry of these compounds in dichloromethane exhibits, besides several reversible reductions, some irreversible waves. Reductive electrolysis of 1 and 3-5 in dichloromethane leads to the removal of the addend and thus to the formation of C60. Reductive electrolysis of 1, 2 and 6 in dichloromethane leads to a different reaction, which we tentatively assign to a reaction with the solvent to form fullerene-CH2Cl products. Electrolyses in the less reactive solvent THF lead to adduct removal for 1 and 3-5. Interestingly, significant formation of bis-adducts from the corresponding monoadducts was observed for 4 and 5. These electrochemically induced reactions, namely addend removal, reaction with the solvent, and addend transfer are influenced by the structure of the addend and by the choice of solvent.
Beulen
M W
MW
Department of Chemistry and Center for Supramolecular Science, University of Miami, Coral Gables, Florida 33124, USA.
Rivera
J A
JA
Herranz
M A
MA
Illescas
B
B
Martín
N
N
Echegoyen
L
L