Transalkylation of Higher Trifluoromethylated Fullerenes with C₇₀: A Pathway to New Addition Patterns of C₇₀(CF₃)₈

Abstract

We report three new isomers of C70(CF3)8, structurally related to p(7)mp-C70(CF3)10, that are inaccessible by direct trifluoromethylation, but can be easily identified among the products of the transalkylation of higher trifluoromethylfullerenes with C70. The reported compounds are characterized by UV/Vis, 1 D and 2 D COSY (19)F NMR spectroscopy, and DFT calculations. A rather unusual addition pattern is observed in p(6),i-C70(CF3)8 in which one addend is attached remotely from the others; polarization of the adjacent unsaturated bonds by the addend makes the molecule readily oxidizable.

CF2‐Functionalized Trifluoromethylated Fullerene C70(CF3)8(CF2): Structure, Electronic Properties, and Spontaneous Oxidation at the Bridgehead Carbon Atoms

“…One of the sets can be attributed to the pristine C s -8CF 2 compound. The second set includes: (1) an AX spin system at δ F of À 112.6 and À 129.7 ppm with J FF value of 259.3 Hz due to a CF 2 group with inequivalent F atoms; (2) a quartet signal at δ F = À 53.4 ppm with J FF of 13.2 Hz due to the two equivalent terminal CF 3 groups (note their considerable upfield shifting due to the nearly eclipsed conformations of the terminal CF 3 groups locked by the nearby hydroxyls, the effect already described elsewhere [17,18,31] ); and (3) a septet signal and two unresolved multiplets (À δ F of 61.0-64.9 ppm) due to the rest three pairs of equivalent CF 3 groups. Obviously, this second set of signals corresponds to the C ssymmetrical [C s -8CF 2 ](OH) 2 .…”

“…[13][14][15][16][17] In the C s -C 70 (CF 3 ) 8 , the terminal groups show the shortest F···F distances to the neighboring ones of ca 2.52 Å, [8] which translates into J FF of 16.1 Hz. [18] Addition of a CF 2 group at the pole of C s -C 70 (CF 3 ) 8 has little influence on CF 3 groups. The shortest F···F distances are 2.505(5) (A-B) and 2.572(5) Å (G-H), in agreement with the above presented J FF values.…”

“…[18] Briefly, fullerene C 70 (Fullerene-center, 99.8%; 50 mg) and an excess of CF 3 I (P&M-Invest, 98%; ca 1 mL) were sealed in a glass ampoule. Annealing of reaction mixture at 420°C for 72 h afforded a mixture C 70 (CF 3 ) [12][13][14][15][16][17][18][19][20] . Then obtained mixture (40 mg) and pristine C 70 (15 mg) were sealed in a glass ampoule and exposed at 450°C for 40 h to yield a mixture C 70 (CF Oxidation and hydration of C s -C 70 (CF 3 ) 8 CF 2 .…”

Regioselective Synthesis of [6,6]‐Open and [5,6]‐Closed C70(CF3)8[CH2] Methanofullerenes with Rapid [6,6]‐to‐[5,6] Phototransformation

“…10.8°for the same carbon atoms in the parent C s -C 70 (CF 3 ) 8 ]. Proximity of the CH 2 group results in a slight upfield shift of the quartet signal A due to the terminal CF 3 groups with respect to the parent C s -C 70 (CF 3 ) 8 (-66.4 vs. -65.7 ppm [31] ). The NMR spectroscopic data for compound 4 are in good agreement with the X-ray results and DFT-GIAO calculations (see Table 1).…”

Facile Separation, Spectroscopic Identification, and Electrochemical Properties of Higher Trifluoromethylated Derivatives of [70]Fullerene

“…More, importantly,t he UV/Vis spectroscopic properties are of key significance with regard to optoelectronic applications. [12,[45][46][47][48][49][50] The spectra of the individual C 70 (CF 3 ) n compounds considered in the presents tudy are showni nF iguresS9-S13 in the Supporting Information. Except for the isomers 12-I and 12-II,t he spectra of which coincide with those previously reported, [11,12] the spectroscopic data are reported for the first time.…”