Effective derivatization and extraction of insoluble missing lanthanum metallofullerenes La@C2n (n = 36–38) with iodobenzene

Abstract

Extraction of insoluble metallofullerenes, La@C 2n (n = 36-38), was conducted with dichlorobenzene, chlorobenzene, and iodobenzene as a solvent under reflux condition. When iodobenzene was used, La@C 2n (n = 36-38) was successfully extracted as the corresponding phenyl adducts, such as La@C 72 (C 6 H 5), La@C 74 (C 6 H 5), and La@C 76 (C 6 H 5). The number of isomers of corresponding adducts, La@C 72 (C 6 H 5) and La@C 74 (C 6 H 5), were reduced to one-third of that in 1,2,4-trichlorobenzene-extracts, which was reported previously. Based on the spectroscopic analysis, the carbon cages of La@C 72 (C 6 H 5) and La@C 74 (C 6 H 5) were deduced to be La@C 2 (10612)-C 72 (C 6 H 5) and La@D 3h-C 74 (C 6 H 5), respectively. The addition site carbon possessing very high radical character suggests that the corresponding adducts were produced by the addition of phenyl radical generated from iodobenzene on metallofullerenes.

Crystallographic characterization of Lu2C2n (2n = 76–90): cluster selection by cage size

“…Therefore, it is highly possible that Lu 2 @ I h (7)-C 80 is generated together with Lu 2 @ C 2v (5)-C 80 during the arc-discharge process, but it may form insoluble products in the raw soot due to its radical character and thus is absent in the usual solvent extract (Table 2). 56–58 As for Lu 2 C 82 , a previous report has revealed that Lu 2 @ C s (6)-C 82 and Lu 2 @ C 3v (8)-C 82 are both lower in energy than any of the Lu 2 C 2 @C 80 isomers (Table 2). 39 Accordingly, for a composition of Lu 2 C 76–82 , Lu 2 @C 2 n is always more stable than the corresponding carbide form Lu 2 C 2 @C 2 n –2 , indicating that the formation of di-EMFs is energetically favorable within this cage size range.…”

Turning On the Near-Infrared Photoluminescence of Erbium Metallofullerenes by Covalent Modification

“…Er@ C 76 (C 6 H 5 ) was prepared in a similar process using iodobenzene as the extraction solvent instead of 1,2,4-trichlorobenzene. 26 The purification process for Er@C 76 (C 6 H 5 ) is shown in Figure S2.…”

“…Purified Er@C 72 (C 6 H 3 Cl 2 ) was obtained by high-performance liquid chromatography (HPLC) separation of the products (Figure S1). Er@C 76 (C 6 H 5 ) was prepared in a similar process using iodobenzene as the extraction solvent instead of 1,2,4-trichlorobenzene . The purification process for Er@C 76 (C 6 H 5 ) is shown in Figure S2.…”

Regioselective Radical Reaction of Monometallofullerene Y@C2v(9)-C82 With N-arylbenzamidine Mediated by Silver Carbonate

“…On the other hand, endohedral metal doping of the fullerene cages can generate a novel class of hybrid molecules named endohedral metallofullerenes (EMFs) (Lu et al, 2012;Popov et al, 2013;Yang et al, 2017;Bao et al, 2018). The interaction between the internal metallic unit and fullerene carbon cages renders the chemistry of EMFs more complicated but also intriguing compared to that of empty fullerenes (Lu X. et al, 2011;Maeda et al, 2016). As a result, the amount of metal-mediated reactions of EMFs lags far behind those of fullerenes and the regioselectivity is just satisfactory with the generation of two or more isomers.…”