Synthesis of fluorous fullerene adducts: reversible solubilization of fullerenes in perfluorinated solvents

Fullerene (C60) Diels-Alder adducts with perfluoroalkylated 1,3-cyclopentadiene (1a,b) were synthesized and studied. The perfluoroalkylated cyclopentadiene was found to be less reactive toward C60 than cyclopentadiene itself, possibly because of the electron-withdrawing effect of the side chain. Because of the same effect, the temperature of the retro-Diels-Alder reaction for the fluorinated adducts was lower (70 degrees C) than the reported value (95 degrees C) for the cyclopentadiene adducts of C60. Higher adducts of the fluorous diene and C60 were found to be soluble in perfluorohexane and to show visible partitioning between organic (toluene) and fluorous phases. Also, the Diels-Alder addition of the fluorous diene was accompanied by extensive oxidation of the fullerene core, as revealed by MALDI-TOF data.

Synthesis and characterization of water-soluble amino fullerene derivatives

[formula: see text] A series of amino-substituted methanofullerene derivatives were prepared by mono-, tris-, and hexa-Bingel-Hirsch reactions using an N-protected malonate derivative. Upon scission of the protecting groups, the e,e,e-tris- and octahedral Th hexa-methano amino fullerenes were found to be among the most water-soluble fullerene derivatives yet prepared. 3He NMR data on corresponding adducts of 3He/C60 helped verify the assigned structures. UV spectral studies confirmed the influence of aggregation on solubility of these adducts in water.