Study of the aggregation properties of a novel amphiphilic C60 fullerene derivative

An amphiphilic C-60-derivative, AFE, characterized by the presence of the chiral fragment Of L-acetyl carnitine in its hydrophilic appendage has been synthesized. In binary (THF/H2O) and ternary (THF/MeOH/H2O) solutions, AFE exhibits a strong tendency to self-aggregation, provided that the Hildebrand polarity index, delta, of the solvent is higher than about 15. A stable aqueous solution of aggregated AFE was obtained. Partition experiments between n-octanol and water show that AFE cannot be spontaneously transferred from water into the organic solvent (and vice versa), although it is effectively "salted-out" by common electrolytes. Light scattering and reversed-phase liquid chromatography experiments carried out on the aqueous solution of AFE suggest for the aggregates an average diameter of 120 nm.