Formation of Singly Bonded PhCH₂C₆₀–C₆₀CH₂Ph Dimers from 1,2-(PhCH₂)HC₆₀ via Electroreductive C₆₀–H Activation

Electronic vs Steric Effects on the Stability of Anionic Species: A Case Study on the Ortho and Para Regioisomers of Organofullerenes

“…While the HPLC trace of the oxidation products of 2 − (Figure 4) shows two major fractions with retention time at 6.3 and 9.9 min, which are ascribed to compound 2 and BnC 60 −C 60 Bn, respectively. The formation of BnC 60 −C 60 Bn is verified by the 1 H NMR and UV−vis spectral characterizations as compared with previous work, 14 indicating that the methoxy group is the one being cleaved from 2 upon reduction. The recovery of a significant amount of 2 in the HPLC trace indicates that both 2 − and BnC 60 − are present in the solution of singly reduced 2, suggesting that the decomposition of 2 − is likely a slow process, consistent with the broad nature of the absorption band in the vis-NIR spectrum of 2 − .…”

“…The first redox wave shows an irreversibility nature with E pc at −0.98 V vs Fc/Fc + and a broad oxidation wave ranging from about −0.90 to −0.48 V vs Fc/ Fc + , indicating that a chemical process likely occurs as the compound acquires one electron. Further reduction of the compound results in two quasireversible redox waves with E 1/2 at −1.51 and −1.91 V, and an irreversible oxidation wave around −0.50 V, which are comparable to the redox processes involving the singly bonded C 60 and dimeric species, 14,15 suggesting that compound 2 undergoes a reductive decomposition.…”

The first representative of a new family of the bridgehead-modified difluoromethylenated homofullerenes: electrochemical properties and synthetic availability

“…Thus, a para-linked σ-(C 60 Bn) 2 (Bn = benzyl) dimer has been prepared by bulk electroreduction of C 60 BnH at the first reduction potential; afterwards, the C 60 Bn -anions formed were electrochemicaly oxidized to the corresponding radical species which undergo fast dimerization. [37] Similarly, a σ-(C 60 H) 2 dimer linked through ortho-positions relatively to hydrogen atoms has been obtained by protonation of the chemically generated C 60 •-with an excess of CF 3 COOH. [33] However, the yield was low since the reaction was accompanied by significant impact of H-transfer process yielding C 60 H 2 and C 60 .…”

Vis-Near-IR Spectroscopic and Time-Dependent DFT Study of Reduced Singly Bonded C60 Species

“…As is shown in Figure 1a, the broad reduction wave with E p red at −0.48 V vs SCE corresponds to the reductive disassociation process, where compound 1 is converted to BnC 60 − upon reduction by cleaving the pivot single bond that connects the two C 60 cages. 32 The broad oxidation wave with E p ox at around −0.17 V corresponds to the oxidative association process, where Figure 2 shows the cyclic voltammograms of the neutral, singly, and doubly reduced species of C 60 oxazoline compounds 2a and 2b. The respective voltammograms for 2a and 2b are very similar to each other as a result of structural resemblance between the two compounds.…”

“…The dimeric compound 1 would dissociate into the monomeric singly bonded monoanion BnC 60 − (Scheme 1) upon reduction, which may be facilely converted to BnC 60 2−• (Scheme 1) with further reduction. 32 As for the C 60 oxazolino compound 2a, it would also result in a singly bonded species after transferring two electrons via the heterolytical cleavage of the C 60 −O bond. 33 However, this singly bonded dianionic species (2a 2− , Scheme 1) is different from BnC 60 2−• , as it has only one charge at the C 60 core, while it is also different from BnC 60 − (the type of RC 60 − ), as the addend in 2a 2− also bears a negative charge.…”