Solubilization of [60]Fullerene Owing to Inclusion Complex Formation between Syndiotactic Poly(methyl methacrylate) and the Fullerenes in Polar Solvents

We found [60]fullerene (C 60 ) to be soluble in polar solvents such as acetonitrile and acetone in the presence of syndiotactic poly(methyl methacrylate) (st-PMMA). The solubility of C 60 in acetonitrile drastically increased from 0.00 to 0.27 mg/mL upon the addition of st-PMMA at the polymer concentration of 4 mg/mL. Furthermore, the solubility increased with the concentration of st-PMMA. Transparent st-PMMA films containing C 60 were prepared by casting an acetonitrile solution of C 60 with st-PMMA. X-ray diffraction analysis of the films revealed the formation of st-PMMA/C 60 inclusion complex in which the C 60 molecules were encapsulated within a helical st-PMMA cavity. The st-PMMA films containing C 60 showed high heat resistance, which resulted from the crystalline structure of the inclusion complex, and absorbed light in the UV−vis region because of the presence of chromophoric C 60 molecules.