Bucky-tubes

An alternative mode for dehydrobenzoannulene decomposition was recently reported by Vollhardt et al. [58]. Non-planar hybrid 81, prepared in low yield via cyclodimerization of known triyne 82 [Eq.(3)], reacted explosively at ca. 250°C to give a nearly pure carbon residue. Solvent extraction of the black powder failed to yield soluble materials such as fullerenes however, analysis of the residue by TEM showed formation of bucky onions and bucky tubes [59], in addition... 

Figure 10.47. Structure (j) (truncated icosahedron) is well known to the chemical community as buck-minsterfullerene, C6o, comprising hexagons and pentagons. It has been well established, both chemically and geometrically, that the pentagons in the structure are necessary to effect three-dimensional closure, and without them only open, two-dimensional graphitic layers are formed. All fullerenes, and even the topical Bucky tubes (Figure 10.2), that consist of fused hexagons are open at both ends unless pentagons are incorporated into the structure.

Figure 12.4. Simulated isotherms for the adsorption of argon and nitrogen at 77 K by a 4.4 nm bucky-tube (Maddox and Gubbins, 1995).

We note in passing that the recent transmission electron microscopy pictures of Cgo films by Wang and Buseck show evidence of Cjo-Cgo coalescence to form cylindrical bucky tubes in the solid Film, presumably triggered by the 400-keV electron beam. We wonder if metal atom encapsulation events would occur under similar circumstances with metal-doped fullerene films. 

The discovery of buckminsterfullerene led to a considerable amount of research into its properties and compounds. Particular interest has been shown in trapping metal ions inside the carbon cage to form enclosure compounds. The term fullerene also apphes to derivatives of buckminsterfullerene and to similar clusters (e.g. C70). Carbon structures similar to that in Cgo can also form small tubes, known as bucky tubes. 

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