Selective Synthesis of a Trifluoromethylated Fullerene and the Crystal Structure of C₆₀(CF₃)₁₂

Abstract

Unexpected selectivity: [60]Fullerene and CF3I react selectively at 440 °C to synthesize C60(CF3)12. In the product with S6 symmetry, 12 CF3 groups form a continuous loop of alternating para‐ and meta‐C6(CF3)2 hexagons. In the crystal, the chains of molecules are strengthened owing to stacking interactions and shielding effects from the CF3 groups, thus accounting for the low volatility and solubility of the compound.

Isolation and Structural Characterization of the Most Stable, Highly Symmetric Isomer of C60(CF3)18

“…[3] The reaction product was only partially (90 %) soluble in hexane. According to MALDI MS analysis {negative ion mode, Bruker AutoFlex II TOF (N 2 laser, 337 nm, 1 ns pulse), 2-[(2E)-3-(4-tert-butylphenyl)-2-methylprop-2-enylidene]malononitrile (DCTB, Ն 99 %, Fluka) as a matrix}, the hexane extract contained C 60 (CF 3 ) n compounds with n = 10-18, whereas the insoluble part contained compounds with n = 16 and 18.…”

“…The first synthesis of C 60 (CF 3 ) n with n up to 14 was reported as early as in 1993. [1] Later on, mass spectrometric studies enabled the detection of compounds with 2-22 CF 3 groups.…”

“…[3][4][5][6][7][8] In the case of higher isomers with n = 16, 18, the data are scarce. Three isomers of C 60 (CF 3 ) 16 and one isomer of C 60 (CF 3 ) 18 have been isolated by HPLC from a mixture prepared by trifluoromethylation of C 60 with CF 3 I in a glass ampoule at 380-400°C. Their molecular structures have been determined by means of single-crystal XRD and discussed in terms of mechanistic pathways of their formation and relative energy stability calculated by DFT methods.…”

“…[1] Later on, mass spectrometric studies enabled the detection of compounds with 2-22 CF 3 groups. [2] Preparative methods including a reaction of fullerene with reagents, which easily release CF 3 radicals (CF 3 COOAg, CF 3 I), resulted in the isolation and structural characterization of more than two dozens of C 60 (CF 3 ) n isomers containing not more than 18 CF 3 groups. [3][4][5][6][7][8] In the case of higher isomers with n = 16, 18, the data are scarce.…”

“…[2] Preparative methods including a reaction of fullerene with reagents, which easily release CF 3 radicals (CF 3 COOAg, CF 3 I), resulted in the isolation and structural characterization of more than two dozens of C 60 (CF 3 ) n isomers containing not more than 18 CF 3 groups. [3][4][5][6][7][8] In the case of higher isomers with n = 16, 18, the data are scarce. Three isomers of C 60 (CF 3 ) 16 and one isomer of C 60 (CF 3 ) 18 have been isolated by HPLC from a mixture prepared by trifluoromethylation of C 60 with CF 3 I in a glass ampoule at 380-400°C.…”