Carbon atoms arrangements

Fig. 5. Schematic representation of arrays of carbon nanotubes with a common tubule axial direction in the (a) tetragonal, (b) hexagonal I, and (c) hexagonal II arrangements. The reference nanotube is generated using a planar ring of twelve carbon atoms arranged in six pairs with the symmetry [16,17,30].

In diamond, each carbon atom forms single bonds with four other carbon atoms arranged tetrahedrally around it The hybridization in diamond is sp3. The three-dimensional covalent bonding contributes to diamond s unusual hardness. Diamond is one of the hardest substances known it is used in cutting tools and quality grindstones (Figure 9.12). 

Graphite is planar, with the carbon atoms arranged in a hexagonal pattern. Each carbon atom is bonded to three others, two by single bonds, one by a double bond. The hybridization is sp2. The forces between adjacent layers in graphite are of the dispersion type and are quite weak. A lead pencil really contains a graphite rod, thin layers of which rub off onto the paper as you write (Figure 9.13, p. 242). 

The basic building block of carbon is a planar sheet of carbon atoms arranged in a honeycomb structure (called graphene or basal plane). These carbon sheets are stacked in an ordered or disordered manner to form crystallites. Each crystallite has two different edge sites (Fig. 2) the armchair and zig-zag sites. In graphite and other ordered carbons, these edge sites are actually the crystallite planes, while in disordered soft and hard carbons these sites, as a result of turbostratic disorder, may not... 

Branched Paraffins. Table II contains the relative ionic intensities obtained for 17 different branched paraffins containing from nine to 30 carbon atoms arranged in order of increasing number of side chain substituents. 

Fullerenes (originally buckminsterfullerenes) are a new class of carbon-only molecules the first example discovered in 1985 (Kroto et al., 1985), being composed of 60 carbon atoms arranged in a soccer ball structure (C60). The condensed aromatic... 

Intercalation reactions (14.1) represent the ideal case there is an increase in the inter-layer distance while the carbon atom arrangement within the layers remains unchanged. However, during intercalation of cations from polymer [25] and solid [26] electrolytes, ternary phases (M (solv)yC /C (solv)yX ) are produced because the solvent from the electrolyte is also accepted into the carbon lattice. 

Aliphatic hydrocarbon a hydrocarbon in which the carbon-hydrogen groupings are arranged in open chains that may be branched. The term includes paraffins and olefins and provides a distinction from aromatics and naphthenes, which have at least some of their carbon atoms arranged in closed chains or rings. 

Each graphene sheet is composed of rings of carbon atoms arranged on a hexagonal 2D tiling. This form of carbon has n bonds in addition to the a bonds, as shown in Fig. 4.6, leading to a bond order of 1.33. 

The first strnctnre has the carbon atoms arranged in a linear fashion and is called normal butane or, simply, n-bntane. The second has a branched structure and is termed tTobntane (or, more rigoronsly, 2-methylpropane). 

Figure 1.1 A diamond is made up entirely of carbon atoms arranged in crystal form.

Diamond, the hardest of natural materials, consists of a lattice of carbon atoms arranged in a tetrahedral slruclure at equal distances apait (1.544 A) and bonded by electron pairs in localized molecular orbitals formed by overlapping of Ihe. /> hybrids. See aiticle on Diamond. 

Exercise 21-11 Graphite crystals consist of a network of planar hexagonal rings of carbon atoms arranged in parallel layers. The distance between the layer planes is 3.35 A and all the C-C bonds within the hexagonal network are equal to 1.421 A. 

One of the most famous nanoparticles is the buckyball, a molecule made up of 60 carbon atoms arranged in a soccer-ball shape. Some skin creams now include buckyball molecules. Another widely used nanoparticle is zinc oxide. For years, swimmers applied zinc oxide as a thick sunscreen paste, but the new nano-sized version of the compound is so small that it looks transparent when slathered on as sunblock. The makers of these products say the nanoparticles can reflect light and fight off damage to skin cells better than normal-sized particles. A few cosmetics manufacturers are experimenting with nanoparticles in eye shadow and lipsticks to see if the tiny molecules can produce different colors or new visual effects like iridescence, where colors seem to constantly change. 

Buckyball A very stable molecule of 60 carbon atoms arranged in a soccer-ball shape often used in nanotechnol-... 

PGC sorbents have even more highly homogeneous hydrophobic surfaces than GCB sorbents. PGCs are macroporous materials composed of flat, two-dimensional layers of carbon atoms arranged in graphitic structure. The flat, homogeneous surface of PGC arranged in layers of carbons with delocalized n electrons makes it uniquely capable of selective fractionation between planar and nonplanar analytes such as the polychlorinated biphenyls [92,94,95],... 

From the electronic structure of the lead atom, one would expect the tetraorganolead compounds to form via an spz hybridization of the two s and two p electrons in the outer shell of the lead atom, with the carbon atoms arranged in a tetrahedral configuration around the lead atom. All... 

PGs are named from a hypothetical compound, prostanoic acid, a monocarboxylic acid with 20 carbon atoms, arranged with two side chains with 7 and 8 carbon atoms linked to a cyclopentane ring. PGs have functional groups with oxygen at carbons 9, 11, and 15 of prostanoic acid (see Figure 16.23) and one, two, or three double bonds in the side chain. 

There are three common forms of carbon diamond, graphite, and amorphous carbon. All three are important for electrochemical applications. The ideal graphite structure consists of layers of carbon atoms arranged in hexagonal rings. Metallic properties are exhibited in the direction parallel to the layer planes, while semiconducting properties are exhibited in a perpendicular direction. Because of the anisotropic structure of graphite, it indeed possesses anisotropic properties. 

Fullerene A convex cage of atoms with only hexagonal and/or pentagonal faces a molecular form of pure carbon discovered in 1985. The most common form produced is buckminsterfullerene (C60), with 60 carbon atoms arranged in a spherical structure. Larger fullerenes contain from 70 to 500 carbon atoms. Also known as Bucky Balls. ... 

The recent discovery of spherical molecules containing 60 carbon atoms arranged over the surface of a sphere, each atom being linked to three... 

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