Chemistry of Fullerene Epoxides: Synthesis, Structure, and Nucleophilic Substitution-Addition Reactivity

Abstract

Fullerene epoxides, C60On, having epoxide groups directly attached to the fullerene cage, constitute an interesting class of fullerene derivatives. In particular, the chemical transformations of fullerene epoxides are expected to play an important role in the development of functionalized fullerenes. This is because such transformations can readily afford a variety of mono- or polyfunctionalized fullerene derivatives while conserving the epoxy ring arrangement on the fullerene surface, as seen in representative regioisomeric fullerene polyepoxides. The first part of this review addresses the synthesis and structural characterization of fullerene epoxides. The formation of fullerene epoxides through different oxidation reactions is then explored. Adequate characterization of the isolated fullerene epoxides was achieved by concerted use of NMR and LC-MS techniques. The second part of this review addresses the substitution of fullerene epoxides in the presence of a Lewis acid catalyst. Most major substitution products have been isolated as pure compounds and their structures established through spectroscopic methods. The correlation between the structure of the substitution product and the oxygenation pattern of the starting materials allows elucidation of the mechanistic features of this transformation. This approach promises to lead to rigorous regioselective production of various fullerene derivatives for a wide range of applications.

Fullerene oxidation and clustering in solution induced by light

“…Light exposure of polymer-fullerene composite films has been shown to profoundly impact their stability and morphology [35][36][37]. Additionally, fullerene epoxides can be used to synthesise further functionalised fullerenes [38], and this method appears to be relatively simple and scalable for fullerene epoxide production, and could be conducted in a flow reactor [39]. Cluster formation is expected to have significant implications for film formation, fullerene crystallisation and thus for thin film morphology.…”

Water Entrapped inside Fullerene Cages: A Potential Probe for Evaluation of Bond Polarization

“…We synthesized C 60 CR 2 , [13] C 60 NR, [14] C 60 O, [15] and C 60 O 2 [15] from empty C 60 according to reported methods.E ndohedral derivatives H 2 O@C 60 Xw ere also synthesized in as imilar manner using H 2 O@C 60 (100 %e ncapsulation), which was prepared in six steps from C 60 [16] using the molecular surgery method. Note that entrapped H 2 Oinside the C 60 X cage is geometrically isolated from outside environment.…”

“…Note that entrapped H 2 Oinside the C 60 X cage is geometrically isolated from outside environment. We synthesized C 60 CR 2 , [13] C 60 NR, [14] C 60 O, [15] and C 60 O 2 [15] from empty C 60 according to reported methods.E ndohedral derivatives H 2 O@C 60 Xw ere also synthesized in as imilar manner using H 2 O@C 60 (100 %e ncapsulation), which was prepared in six steps from C 60 [16] using the molecular surgery method. [17] The [6,6]isomer of H 2 O@C 60 CR 2 (R = phenyl) was synthesized from H 2 O@C 60 in 23 %y ield by 1,3-dipolar cycloaddition of diphenyldiazomethane generated in situ and subsequent thermal isomerization (Scheme 1a).…”

Solid State Physicochemical Properties and Applications of Organic and Metallo- Organic Fullerene Derivatives

“…Also in this case there is a limit to the maximum number of epoxy additions. For epoxydized C 60 O n , the simplest derivatives containing epoxy bridges, the maximum number of adducts is 18 [35]; for [2+1]cycloaddition to carbon atoms of aromatic sideadducts, the largest reported number of adducts is six, although the most common cases are those of mono-or bisadducts (e.g. PCBM and bis-PCBM).…”