A novel approach for the synthesis of C60 fullerenes containing strained 2,3-dimethylenebicyclo[2,2,0]hexane fragments

The present article details a novel approach for introducing strained 2,3-dimethylenebicyclo[2,2,0]hexane structures into the C60 fullerene molecule, based on the reaction of C60 with substituted propargylamines, promoted by the Ti(Oi-Pr)4 and EtMgBr system. The theoretical LUMO energies of the strained C60 derivatives calculated at the PBEPBE/6-311G(d,p) level of theory are from −3.93 to −4.09 eV, which indicates that these compounds seem to be promising as electron-acceptor materials for bulk heterojunction organic solar cells.