Benzothienofullerenes were synthesized using fullerenyl cations as key intermediates. The reaction proceeded through a nucleophilic attack of the sulfur atom as a weak nucleophile to the fullerenyl cation electrophile. A monoarylated fullerene, (2-methylthiophenyl)hydrofullerene, C60ArH (Ar = C6H4-SMe-2 and so on; four derivatives) was subjected to deprotonation with KOtBu to form a fullerenyl anion ArC60-, followed by oxidation using I2 to generate a fullerenyl cation ArC60+, leading to intramolecular demethylative cyclization via fullerene cation-S interaction to the product. Electrochemical and computational studies revealed slightly narrower band gap of this compound than usual fullerene derivatives because of the relatively high-lying HOMO of the fused thieno moiety.
ASJC Scopus subject areas
- Organic Chemistry