Fullerene

About: Fullerene is a research topic. Over the lifetime, 12723 publications have been published within this topic receiving 359173 citations.

Formation of single-wall carbon nanotubes by laser ablation of fullerenes at low temperature

Abstract: Laser ablation products from fullerene materials have been studied by transmission electron microscopy and Raman spectroscopy. Using nickel and cobalt as a catalyst, single-wall carbon nanotubes were produced at an ambient temperature of 400 °C. The results were compared with those using graphite as starting materials. It is suggested that the formation of single-wall carbon nanotubes is controlled by both the availability of proper precursors and the activity of the metal catalyst.

Direct Solvent-Free Amination of Closed-Cap Carbon Nanotubes: A Link to Fullerene Chemistry

Abstract: We attempted the direct solvent-free amination of closed caps of multiwalled carbon nanotubes (MWNTs) with octadecylamine (ODA), which is essentially similar to the amination of spherical fullerenes. Thermogravimetric analysis revealed a relatively high content of organics in the product of derivatization (ODA-MWNTs), suggesting that a large ODA fraction is distributed over MWNT sidewalls through chemical attachment. This was confirmed by high-resolution transmission electron microscopy observations. Quantum chemical calculations showed that the presence of pyracylene units in the closed caps is not crucial for the amine addition, although the site specificity of the reaction does depend on the mutual position of five-membered rings. If the caps contain pyracylene units, then the addition preferentially takes place on their 6,6 bonds; if they do not, then the preferential reaction sites are C−C bonds of the pentagons. Whereas ideal nanotube sidewalls composed of solely benzene rings were found to be inert...

Physical and chemical evidence for metallofullerenes with metal atoms as part of the cage

Abstract: SINCE the discovery of fullerenes1, efforts have been made to trap metal atoms inside fullerene cages2, and both endohedral3,4 and exohedral5,6 metallofullerenes have been synthesized. There is, however, a third possibility: a 'networked' metallofullerene, where the metal atom is incorporated into the carbon cage. Here we report the results of experiments to study the structure and reactivity of gas-phase fullerenes doped with niobium (NbCn+ with n = 28–50). These experiments, which use injected-ion drift-tube tech-niques, indicate that for fullerenes containing an even number of carbon atoms the metal is endohedral, but for fullerenes with an odd number of carbon atoms, the niobium metal is bound as a part of the carbon cage. Thus, networked metallofullerenes appear to be a stable class of metallofullerene. We suggest that such metallo-fullerenes can form if the metal atom retains sufficient electron density to form several strong covalent metal–carbon bonds.

Triplet-state properties and singlet oxygen generation in a homologous series of functionalized fullerene derivatives

Abstract: The main properties of the triplet states and the yields of singlet oxygen generation for a series of methano[60]fullerene adducts with increasing numbers of substituents were determined. The triplet properties investigated are energies, triplet−triplet absorption spectra, extinction coefficients, and quantum yields. A strong correlation is observed between several triplet properties and the topology of the fullerene core. Successive fragmentation of the chromophore of the parent C60 results in higher triplet energies and lower triplet quantum yields. In addition, singlet oxygen quantum yields (φΔ) were determined for all adducts and decrease as the area of the conjugated fullerene core decreases.