An isomeric mixture of C70(C2F5)10 has been synthesized by a high temperature reaction of C70 with C2F5I in a glass ampoule followed by HPLC separation. Partial thermal decomposition of C70(C2F5)10 has been performed to yield a complex mixture of lower derivatives. The molecular structures of nine isomers of C70(C2F5)8 isolated therefrom plus two new isomers of C70(C2F5)10 have been determined by means of single crystal X-ray diffraction. We discuss these newly obtained structures in terms of relative energies and possible formation pathways.