Regioselective Synthesis and Crystallographic Characterization of Nontethered cis-1 and cis-2 Bis(benzofuro)[60]fullerene Derivatives.

The regioselective synthesis of fullerene bis-adducts remains challenging because it produces large amounts of regioisomers. Novel nontethered cis-1 and cis-2 bis(benzofuro)[60]fullerene derivatives were directly synthesized with high regioselectivity by using chlorofullerene C60Cl6 as a precursor. Their structures were determined via spectroscopic data and single-crystal X-ray analysis. A nucleophilic addition elimination mechanism was proposed to elucidate the formation of highly regioselective cis-1 and cis-2 bis-adducts. The potential application of these bis(benzofuro)[60]fullerene derivatives as stabilizers in propellants was also investigated.