Fullerene lattice

One example of a cocrystal containing BEDT-TTF and ferrocene has been reported [104]. The [(BEDT-TTF Cgob lferrocene) adduct was crystallized from a carbon disulfide solution. The unit cell has been determined by single crystal X-ray diffraction but the crystal structure was not reported. An infrared spectroscopic analysis indicates that the charge transfer between the BEDT-TTF and C6o molecules is quite small. It has been suggested that such complexes may offer a means to introduce iron into the fullerene lattice. 

In pristine [60] fullerene, the t band is completely empty while, in contrast, the phase (bee lattice) has a... 

The higher mass fullerenes (C76, Cs4), with multiple isomers of different shapes, also crystallize in the fee structure at room temperature, with an fee lattice constant which is approximately proportional to where n is the number of carbon atoms in the fullerene [53]. 

Except for Ceo, lack of sufficient quantities of pure material has prevented more detailed structural characterization of the fullerenes by X-ray diffraction analysis, and even for Ceo problems of orientational disorder of the quasi-spherical molecules in the lattice have exacerbated the situation. At room temperature Cgo crystallizes in a face-centred cubic lattice (Fm3) but below 249 K the molecules become orientationally ordered and a simple cubic lattice (Po3) results. A neutron diffraction analysis of the ordered phase at 5K led to the structure shown in Fig. 8.7a this reveals that the ordering results from the fact that... 

Property measurements of fullerenes are made either on powder samples, films or single crystals. Microcrystalline C6o powder containing small amounts of residual solvent is obtained by vacuum evaporation of the solvent from the solution used in the extraction and separation steps. Pristine Cgo films used for property measurements are typically deposited onto a variety of substrates (< . , a clean silicon (100) surface to achieve lattice matching between the crystalline C60 and the substrate) by sublimation of the Cr,o powder in an inert atmosphere (e.g., Ar) or in vacuum. Single crystals can be grown either from solution using solvents such as CS and toluene, or by vacuum sublimation [16, 17, 18], The sublimation method yields solvent-free crystals, and is the method of choice. 

Lattice parameter determination, diffractometers in, 26 428 Lattice polymers, fullerene, 12 250, 251 Lattice-type inclusion compounds,... 

Carbon nanotubes (CNTs) constitute a nanostructured carbon material that consists of rolled up layers of sp2 hybridized carbon atoms forming a honeycomb lattice. After diamond, graphite and fullerenes, the one-dimensional tubular structure of CNTs is considered the 4th allotrope of carbon (graphene is the 5th). 

It was found that the intercalation of Cgo fullerene by an alkali metal in stoichiometric ratio (1 1) gives rise to the formation of anion-radical salts, namely, KC50, RbCgg, and CsCgo (Bommeli et al. 1995, Btouet et al. 1996). On slow cooling of the intercalation products, [2 + 2] cycloaddition of the fullerene species that is neighboring a crystal lattice occurs. Linear chain fullerenic polymers are formed. These polymers are stable in air, insoluble in THF, and possess metallic conductivity. They depolymerize only on heating above 320°C. 

As expected for the icosahedral symmetry, the NMR spectrum of Cjq (Figure 1.24) shows one signal, at 5 = 143.2 [25]. Since the amount of fullerene in the NMR samples due to low solubility is small and the spin-lattice relaxation... 

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