Very Large, Soluble Endohedral Fullerenes in the Series La₂C₉₀ to La₂C₁₃₈: Isolation and Crystallographic Characterization of La₂@D₅(450)-C₁₀₀

Abstract

An extensive series of soluble dilanthanum endohedral fullerenes that extends from La(2)C(90) to La(2)C(138) has been discovered. The most abundant of these, the nanotubular La(2)@D(5)(450)-C(100), has been isolated in pure form and characterized by single-crystal X-ray diffraction.

Closed network growth of fullerenes

“…S8). Recently, La 2 @C 100 has been structurally characterized, revealing a nanotubular carbon network 39 . The large metallofullerene, Sm 2 @C 104 , has also been shown to possess a tubular structure 40 .…”

Isolation of Four Isomers of C96 and Crystallographic Characterization of Nanotubular D3d(3)‐C96 and the Somewhat Flat‐Sided Sphere C2(181)‐C96

“…[2,13] Larger fullerene cages have been structurally characterized for the endohedral fullerenes La 2 @D 5 A C H T U N G T R E N N U N G (450)-C 100 and Sm 2 @D 3d A C H T U N G T R E N N U N G (822)-C 104 . [14,15] Here we report the isolation of four isomers of C 96 and the structural characterization of two of these by single-crystal X-ray diffraction. For C 96 there are 187 isomers that obey the isolated pentagon rule (IPR), which alleviates strain in the cage by requiring that each of the twelve pentagons of a fullerene to be surrounded by five hexagons.…”

“…Interestingly, nanotubular fullerenes (i. e. D 5h (1)-C 90 , [13] D 3d (3)-C 96 , La 2 @D 5 A C H T U N G T R E N N U N G (450)-C 100 , [14] and Sm 2 @D 3d A C H T U N G T R E N N U N G (822)-C 104 . [15] ) occur for each of the largest cages that have been fully structurally characterized.…”

Soluble and Tubular Higher Fullerenes that Encapsulate Metals

“…[7] Endohedral metal doping therefore appears promising. [9] They innovatively used chlorobenzene as an HPLC eluent, which has a higher affinity to fullerenes/metallofullerenes than the commonly used toluene, and thereby succeeded in accumulating a fraction containing the large and soluble endofullerenes La 2 C 90 to La 2 C 138 , together with a second series of monolanthanum metallofullerenes with smaller cages and less abundance. [8] The recent work by Balch and colleagues makes a big step toward achieving soluble higher fullerenes.…”