The curved geometry conformation is probably caused by the charge interaction between C60 and TTF, C60 and BTTTF respectively. Because the LUMO energy of C60 is close to the HOMO energy of BTTTF, the D-A reaction to BTTTF-C60 takes place easily.

• C60的LUMO能与BTTTF的HOMO能接近 ；易发生D A反应 ；形成BTTTF C60 .；BTTTF C60和TTF C60的LUMO能仍较低