High‐Temperature Synthesis of the Surprisingly Stable C1‐C70(CF3)10 Isomer with a para7–meta–para Ribbon of Nine C6(CF3)2 Edge‐Sharing Hexagons

Kareev, Ivan E.; Kuvychko, Igor V.; Popov, Alexey A.; Lebedkin, Sergey F.; Miller, Susie M.; Anderson, Oren P.; Strauss, Steven H.; Boltalina, Olga V.

doi:10.1002/anie.200502419

Cited by 74 publications

(74 citation statements)

References 33 publications

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“…1). Among three structur ally characterized isomers of C 60 (CF 3 ) 10 , 3 the addition patterns with isolated hexagons C 6 (CF 3 ) 2 have not been observed. Isomers 3A and C 60 (CF 3 ) 10 B* (with the chain p 3 (mp) 3 ), 3b which differ in the position of only two fluoroalkyl groups, are most similar in the mode of at tachment.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, structural investigation, and theoretical study of pentaf luoroethyl derivatives of [60]fullerene

et al. 2007

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Pentafluoroethyl derivatives of [60]fullerene C 60 (C 2 F 5 ) n (n = 6, 8, and 10) were synthe sized by the reaction of C 60 with C 2 F 5 I in glass ampoules at 380-440 °C. Isomers of composi tion C 60 (C 2 F 5 ) 6 (one isomer), C 60 (C 2 F 5 ) 8 (five isomers), and C 60 (C 2 F 5 ) 10 (two isomers) were isolated by chromatographic separation. Their molecular structures were established by X ray diffraction. The relative stabilities of isomers were compared by density functional theory calculations.Perfluoroalkyl derivatives of fullerenes are thermally and electrochemically stable compounds. Due to the pres ence of attached electron withdrawing groups, these com pounds hold promise for the use in photovoltaics. A cer tain advantage of these compounds over fluorofullerenes is associated with high chemical stability, in particular, with resistance against hydrolysis.Perfluoroalkyl derivatives of fullerenes were synthe sized for the first time in 1993. 1 The reactions of fullerene with reagents, which readily release fluoroalkyl radicals on heating or irradiation (fluoroalkyl iodides or fluoro acyl peroxides), produced compounds containing up to 16 fluoroalkyl groups. Mixtures of trifluoromethyl (3-14 CF 3 groups), pentafluoroethyl (9-16 C 2 F 5 groups), and perfluorohexyl (6-12 C 6 F 13 groups) deriva tives of fullerene C 60 were characterized by mass spec trometry. Subsequent studies have been focussed prima rily on the synthesis and investigations of trifluoromethyl derivatives. Trifluoromethyl radicals were generated by thermal dissociation of either silver trifluoroacetate 2 or trifluoromethyl iodide. 3,4 As a rule, individual isomers are isolated by the HPLC separation of mixtures produced in the synthesis. The derivatives C 60 (CF 3 ) n (n = 8-12 (see Refs 3-6) and 16-18 (see Ref. 7)) and C 70 (CF 3 ) m (m = 6-18) 8-13 were isolated and characterized by X ray diffraction.Data on individual pentafluoroethyl derivatives are more scarce. The reaction of C 2 F 5 I vapor with [60]fullerene at 440 °C afforded a mixture of products, from which one isomer of C 60 (C 2 F 5 ) 6 and one isomer of C 60 (C 2 F 5 ) 8 were isolated and structurally characterized. 14 Oxide C 60 (C 2 F 5 ) 4 O was isolated from a mixture prepared analogously, and its molecular structure was established. 15 In the present study, we performed the high tempera ture ampoule synthesis of the pentafluoroethyl derivatives C 60 (C 2 F 5 ) n (n = 6 (1), 8 (2), and 10 (3)) with the use of C 2 F 5 I. The separation of the resulting mixtures allowed us to isolate eight new isomers containing from six to ten attached pentafluoroethyl groups. These isomers were studied by X ray diffraction. The relative energy stabili ties of the pentafluoroethyl derivatives were investigated by quantum chemical methods, and these results were compared with the data for trifluoromethyl analogs. ExperimentalSynthesis. The reaction of fullerene C 60 with C 2 F 5 I was carried out in evacuated glass ampoules. A mixture of fullerene C 60 (99.98%, TermUSA; 30-50 mg) and C 2 F 5 ...

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Section: Resultsmentioning

confidence: 99%

Synthesis, structural investigation, and theoretical study of pentaf luoroethyl derivatives of [60]fullerene

et al. 2007

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“…It should be noted that, despite the seemingly substantial difference in the numeration of trifluoromethylated fullerenes C 70 (СF 3 ) n , all of them with n ≥ 12 contain a structural motif of the most thermo dynamically stable isomer, C 70 (СF 3 ) 10 (see Ref. 6) indicated in the Schlegel diagram for C 70 (СF 3 ) 12 III by the hatched ellipse (see Fig. 1).…”

Section: Resultsmentioning

confidence: 99%

“…At present, experimentally determined addition patterns (locations of attached groups) on the С 70 fullerene sphere are known for 30 C 70 (CF 3 ) n isomers (n = [6][7][8][9][10][11][12][13][14][15][16][17][18]. The total number of theoretically possible isomers is of the order of tens and hundreds thousands.…”

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New C70(CF3) n isomers (n = 12, 14, 16). Realkylation and addend rearrangements

et al. 2009

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New isomers of trifluoromethyl derivatives of [70]fullerene, C 70 (CF 3 ) 12 (one isomer), C 70 (CF 3 ) 14 (three isomers), and C 70 (CF 3 ) 16 (one isomer) were synthesized, chromatographi cally isolated, and characterized by single crystal X ray analysis. Three of the five new isomers were obtained by annealing a mixture of higher trifluoromethyl derivatives (realkylation*). Trifluoromethylation of two individual C 70 (CF 3 ) 12 isomers revealed rearrangements of CF 3 groups on the fullerene sphere along with the direct addition to the double bonds. The relative energies of the isomers were calculated using the density functional theory.

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“…Synthesis in a flow apparatus, that is, with gaseous CF 3 I passing at atmospheric pressure over C 60 or C 70 at 460°C followed by the collection of volatile compounds in a cold zone, resulted in the formation of C 60 (CF 3 ) n (n = 8, 10, 12) [12,17,[19][20][21] and C 70 (CF 3 ) n (n = 10, 12). [27][28][29] Synthesis at a higher temperature (550°C) led to the lower trifluoromethylated fullerenes C 60 (CF 3 ) n (n = 2-100). [23] The interaction of C 60 or C 70 fullerenes with CF 3 I vapor at around [a] Weight of the combined sublimates.…”

Section: Synthesismentioning

confidence: 99%

Synthesis, Structure, and Theoretical Study of Lower Trifluoromethyl Derivatives of [60]Fullerene

et al. 2007

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A number of C60(CF3)n compounds with n = 2–10 have been synthesized by the reaction of C60 with silver trifluoroacetate and successfully isolated by means of HPLC. This resulted in the first crystal structure determination of six lower trifluoromethyl derivatives with n = 2 (single isomer), 4 (two isomers), and 6 (three isomers). A kinetic model of sequential trifluoromethylation based on the Bell–Evans–Polanyi principle has been used to explain the experimentally observed isomeric distribution in the mixtures of C60(CF3)n compounds up ton = 6. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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High‐Temperature Synthesis of the Surprisingly Stable C₁‐C₇₀(CF₃)₁₀ Isomer with a para⁷–meta–para Ribbon of Nine C₆(CF₃)₂ Edge‐Sharing Hexagons

Cited by 74 publications

References 33 publications

Synthesis, structural investigation, and theoretical study of pentaf luoroethyl derivatives of [60]fullerene

Synthesis, structural investigation, and theoretical study of pentaf luoroethyl derivatives of [60]fullerene

New C70(CF3) n isomers (n = 12, 14, 16). Realkylation and addend rearrangements

Synthesis, Structure, and Theoretical Study of Lower Trifluoromethyl Derivatives of [60]Fullerene

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