Trifluoromethyl Derivatives of Elusive Fullerene C 98

Data concerning the isomeric composition of C 98 and the chemistry of C 98 derivatives are scarce due to very low abundance of C 98 in the fullerene soot. Trifluoromethylation of C 98 ‐containing mixtures followed by HPLC separation of CF 3 derivatives and single crystal X‐ray diffraction study resulted in structural characterization of four compounds C 98 (248)(CF 3 ) 18/20 , C 98 (116)(CF 3 ) 18 , and C 98 (120)(CF 3 ) 20 . To date, these compounds represent the largest fullerenes isolated as CF 3 derivatives with experimentally determined molecular structures. The addition patterns of C 98 (CF 3 ) 18/20 are discussed in detail revealing the stabilizing factors, such as isolated double C=C bonds and benzenoid rings on C 98 fullerene cages. A detailed comparison with the addition patterns of the known C 98 Cl n allowed us to contribute to the better understanding the chemistry of elusive C 98 fullerene.