Solubility of fullerene (C60) in a variety of solvents

Abstract

The room temperature solubility of pure C60 has been determined in 47 solvents. The solubilities cover a wide range, from 0.01 mg/mL in methanol to 50 mg/mL in 1-chloronaphthalene. The solubilities in CS2, toluene, and hexane, three of the commonly employed solvents, are 7.9,2.8, and 0.04 mg/mL, respectively. An examination of the solubilities of C60 as a function of the solvent properties such as index of refraction, dielectric constant, molecular size, Hildebrand solubility parameter, and H-bonding strength reaffirms the century-old principle ''like dissolves like''. No single solvent parameter can uniformly predict the solubility Of C60, but a composite picture of solvents with high solubility for C60 emerges: large index of refraction, dielectric constant around 4, large molecular volume, Hildebrand solubility parameter equal to 10 cal1/2 CM-3/2, and tendency to act as a moderate strength nucleophile.