Chloro Derivatives of Isomers of a Giant Fullerene C104 : C104 (234)Cl16/18 , C104 (812)Cl12/24 , and C104 (811)Cl28.

The chemistry of a giant fullerene, C104 , has been extended by the synthesis and structural study of several chloro derivatives of three isolated pentagon rule (IPR) isomers of C104 nos. 234, 812, and 811. In the structure of C104 (234)Cl16/18 , two molecules with 16 and 18 attached Cl atoms occupy the same crystallographic site with an occupancy ratio of 61/39. The structures of C104 (812)Cl12 and C104 (812)Cl24 demonstrate substructure relationships of their chlorination patterns with single and double Cl attachments to 12 cage pentagons. The structure of C104 (811)Cl28 is compared with the known C104 (811)Cl24 thus revealing dramatic changes in the chlorination pattern, which occur with relatively small increases in the degree of chlorination.

Synthesis, Isolation and Structure of Trifluoromethylated Fullerene D3-C78, C78(1)(CF3)10-18.

High-temperature trifluoromethylation of fullerene C78 followed by HPLC separation of C78 (CF3)n derivatives resulted in the isolation and X-ray structural characterization of 15 compounds, that is, two C78(1)(CF3)10, three C78 (1)(CF3)12, four C78 (1)(CF3)14, and five C78 (1)(CF3)16 isomers as well as one isomer of C78(1)(CF3)18. The addition patterns of the C78(1)(CF3)n molecules are discussed in terms of trifluoromethylation pathways and relative formation energies.

Capturing an unstable C100 fullerene as chloride, C100(1)Cl12, with a nanotubular carbon cage.

The chlorination of a HPLC C100 fraction afforded C100(1)Cl12 with an unprecedented nanotubular carbon cage of a highly unstable D5d-C100 fullerene.

Synthesis, structure, and theoretical study of trifluoromethyl derivatives of C84(23) fullerene.

Trifluoromethylation of a higher fullerene mixture with CF3I was performed in ampoules at 550 °C. HPLC separation followed by crystal growth and X-ray diffraction study resulted in the structure elucidation of nine CF3 derivatives of D2d-C84 (isomer 23). The molecular structures of C84(23)(CF3)4, C84(23)(CF3)8, C84(23)(CF3)10, C84(23)(CF3)12, two isomers of C84(23)(CF3)14, two isomers of C84(23)(CF3)16, and C84(23)(CF3)18 were discussed in terms of their addition patterns and the relative formation energies. Extensive theoretical DFT calculations were performed to identify the most stable molecular structures. It was found that the addition of CF3 groups to the C84(23) fullerene is governed by two main rules: no additions in positions of triple hexagon junctions and predominantly para additions in C6(CF3)2 hexagons on the fullerene cage. The only exception with an isolated CF3 group in C84(23)(CF3)12 is discussed in more detail.

Synthesis, structure, and theoretical study of trifluoromethyl derivatives of C84(22) fullerene.

Trifluoromethylation of higher fullerene mixtures with CF(3)I was performed in ampoules at 400 to 420 and 550 to 560 °C. HPLC separation followed by crystal growth and X-ray diffraction studies allowed the structure elucidation of nine CF(3) derivatives of D(2)-C(84) (isomer 22). Molecular structures of two isomers of C(84)(22)(CF(3))(12), two isomers of C(84)(22)(CF(3))(14), four isomers of C(84)(22)(CF(3))(16), and one isomer of C(84)(22)(CF(3))(20) were discussed in terms of their addition patterns and relative formation energies. DFT calculations were also used to predict the most stable molecular structures of lower CF(3) derivatives, C(84)(22)(CF(3))(2-10). It was found that the addition of CF(3) groups to C(84)(22) is governed by two rules: additions can only occur at para positions of C(6)(CF(3))(2) hexagons and no additions can occur at triple-hexagon-junction positions on the fullerene cage.