Synthesis of fulleropyrrolidine–imidazolium salt hybrids and their solubility in various organic solvents

Eight types of fulleropyrrolidine–imidazolium hybrids have been synthesized and their solubility determined in various types of organic solvents. The solvent solubility of fullerene derivatives depends on the alky side chain on the imidazolium ring; modification of solvent solubility of the fulleropyrrolidine–imidazolium hybrids has thus been accomplished by introduction of an appropriate alkyl group using imidazoyl moiety as the ‘functional group connector’. The imidazolium group seems to act not only as the connector but also as an important functional group that controls the solubility.