Methoxylation of Singly Bonded 1,4–1′,4′-BnC₆₀–C₆₀Bn Dimer: Preferential Formation of 1,4-C₆₀ Adduct with Sterically Less Demanding Addends and Stability Difference between 1,2- and 1,4-OMe(Bn)C₆₀

Abstract

Methoxylation of the singly bonded 1,4-1',4'-BnC60-C60Bn dimer afforded 1,4-OMe(Bn)C60, a 1,4-C60 adduct with sterically less demanding addends, as the major adduct. The situation was different from that of direct functionalization of C60, where 1,2-OMe(Bn)C60 was obtained as the major product. The reaction was studied with in situ vis-NIR spectroscopy and computational calculations to obtain a better understanding of this unusual regioselectivity. The stability difference between 1,2- and 1,4-OMe(Bn)C60 was studied.

Electrochemically Promoted Benzylation of [60]Fullerooxazolidinone

“…The 13 C NMR spectrum of 2 showed 50 peaks for the 58 sp 2 -carbon atoms in the 156.15-137.93 ppm range and two sp 3 -carbon atom peaks of the fullerene cage at 68.28 and 60.01 ppm, and the 13 C NMR spectra of 3 and 4 displayed at least 52 peaks between 156.04-135.95 ppm for the 56 sp 2 -carbon atoms and four peaks between 90.31-56.52 ppm for the four sp 3 -carbon atoms of the fullerene skeleton, agreeing with their C 1 symmetry. The UV-vis spectrum of 2 showed a broad absorption band at 446 nm, which resembled those of other 1,4-adducts of C 60 [35,40,41]. The UV-vis spectrum of 3 exhibited two strong absorption bands at 254 and 324 nm, together with three weak absorption bands at 405, 431 and 690 nm, which were similar to those of 1,2,3,16-adducts in the literature [26,27,[30][31][32][33]35,37,38].…”

KOtBu-Mediated, Three-Component Coupling Reaction of Indoles, [60]Fullerene, and Haloalkanes: One-Pot, Transition-Metal-Free Synthesis of Various 1,4-(3-Indole)(organo)[60]fullerenes

“…The 1,4-[60]­fullerene bisadducts bearing two organic groups in a 1,4-relative regiochemistry on the fullerene core have been studied extensively and reported as excellent n-type acceptor materials for high-performance organic photovoltaics. − The two different organic addends of the unsymmetrical 1,4-fullerene adducts produce an increased absorption in the visible light region, a higher LUMO energy level compared with the 1,2-adducts, − and an easy modification of materials’ solubility in a variety of solvents. − Motivated by the special properties of 1,4-adducts, a number of methods have been developed for synthesizing various 1,4-fullerene derivatives . The indole ring system represents a key structural element that occurs ubiquitously in optoelectronic functional materials .…”

Synthesizing 1,23-C60 Adducts with Improved Efficiency: A Type of Stable and Highly Soluble C60 Derivatives

“…The 1,7-addition (conventionally known as 1,4-addition according to the trivial numbering of C 60 ) introduces one [5,6]-double bond between a five- and a six-membered ring via the para-addition across a six-membered ring, which is predicted to increase the system energy by 8.5 kcal/mol . Such an addition pattern is preferential for the bulky addends, where the unfavorable energy increase could be compensated for by a decrease in steric hindrance . As the addends become even larger, the reaction might undergo the 1,23-addition (conventionally known as 1,16-addition according to the trivial numbering of C 60 ) with the addends being further apart as observed for the bulky silyl groups, even though it may introduce two unfavorable [5,6]-double bonds.…”