Capturing C₉₀ Isomers as CF₃ Derivatives: C₉₀(30)(CF₃)₁₄, C₉₀(35)(CF₃)_16/18, and C₉₀(45)(CF₃)_16/18

Abstract

High-temperature trifluoromethylation of a C90 isomeric mixture with CF3 I followed by HPLC separation of C90 (CF3)n isomers resulted in the isolation of several individual C90 (CF3)14-18 compounds. Single crystal X-ray diffraction with the use of synchrotron radiation resulted in the structure determination of C90 (30)(CF3)14 , C90 (35)(CF3)16/18 , and C90 (45)(CF3)16/18 . Their addition patterns are discussed and compared with the known isomers C90 (30)(CF3)18 and C90 (35)(CF3)14 , respectively. The presence of the most stable C90 isomer, C90 (45), in the fullerene soot has been confirmed for the first time.

From C60 to Infinity: Large-Scale Quantum Chemistry Calculations of the Heats of Formation of Higher Fullerenes

“…The initial structures for geometry optimizations were taken from the Supporting Information of ref . For higher fullerenes for which multiple isomers exist, we have examined the forms that were found to be of the lowest energies. ,− They correspond to isomers 3 (C 78 ), 22 (C 84 ), 45 (C 90 ) and 183 (C 96 ) according to the numbering scheme of ref , and have symmetries of C 2v for C 78 , D 2 for C 84 , C 2 for C 90 and D 2 for C 96 . Literature scale factors were applied to the frequencies in the calculation of ZPVE and Δ H 298–0 values.…”

The First Experimentally Confirmed Isolated Pentagon Rule (IPR) Isomers of Higher Fullerene C98 Captured as Chlorides, C98(248)Cl22 and C98(116)Cl20

“…[2,3] Isomers of even higher pristine fullerenesc ould be unambiguously identified by crystallographic studies of either co-crystals with metal porphyrins (e.g.,C 90 and C 96 ) [4] or exohedral derivatives. [5][6][7][8][9][10] High-temperature trifluoromethylation followedby HPLC isolation of CF 3 derivatives and crystallization of individual full-erene(CF 3 ) n compounds allowed the experimental identification of fullerenei somerso fC 90 , [5] C 92 , [6] C 94 , [7] and C 96 . [8] The method of chlorinationw ith excesso fi norganic chlorides (SbCl 5 ,V Cl 4 , ICl, etc.)…”

“…Subfractions 3 and 4 in amountso fa pproximately 0.02-0.03 mg each were placed into thick-walledglass ampoules, which were evacuated and heateda t3 60 8Cw ith excesso f VCl 4 (ca. 0.4 mL) and ad rop of SbCl 5 for four weeks.A fter the ampoules were cooled and opened, the reactionp roducts were washed with HCl and water to remove excessS bCl 5 and VCl 4 leaving tiny orange-colored crystals.…”