Single Aromatic Layer

Number of the Coronene Ovalene Single Aromatic Layer Graphite (Calculated) ... 

FIG U RE 1.41 (a) Reciprocal space of a single aromatic layer of diameter La. (b) Turbostratic stack of two graphenes, (c) Turbostratic stacks in azimuthal disorder, (d) Reciprocal space of sketch (c). 

APPENDIX IMAGING OF A SINGLE AROMATIC LAYER 1.A.1 Single-Wall Nanotube [26,35]... 

FIGURE 1.57 Transmission electron microscopy image of strongly activated anthracite showing pores formed by single aromatic layers (arrows). (From G.R. Millward and D.A. Jefferson. Lattice resolution of carbon by electron microscopy. In Chemistry and Physics of Carbon 14 (P.L. Walker Jr. and P.A. Thrower, eds.) Marcel Dekker, New York, 1978, 1-82. With permission.)... 

Victorian brown coals are thought to be largely amorphous, containing aromatic layers of single substituted benzene rings crosslinked by aliphatic chains to form a three dimensional structure. Their carbon content is quite low, varying from 60 to 70. One would therefore expect its porous system to be somewhat like that of an open structure having micropores which are randomly-oriented. In this preliminary study two samples of Yallourn ream coal were taken from the Yallourn open cut mine in the Latrobe Valley, Victoria, Australia. The samples, a pale and a medium dark lithotype, are representative of the extremes in coal types found in the Yallourn ream. 

The theory of turbostratic order is adopted by most of the members of the International Union of Crystallography. It is treated in many papers, for example, in [2,3,5-7,14-16,69-71,110-112]. A clear description is detailed in the Appendix of [2]. Such order implies the occurrence of parallel aromatic layers rotated at random with very small angle a (<1°) forming stacks. Let us start with a single layer of... 

Graphene is a single carbon layer of the graphite structure, describing its nature by analogy to a polycyclic aromatic hydrocarbon of quasi-infinite size. 

In graphite each carbon atom is bound to three others in the same plane and here the assumption of inversion of a puckered layer is improbable, because of the number of atoms involved. A probable structure is one in which each carbon atom forms two single bonds and one double bond with other atoms. These three bonds should lie in a plane, with angles 109°28 and 125°16,l which are not far from 120°. Two single bonds and a double bond should be nearly as stable as four single bonds (in diamond), and the stability would be increased by the resonance terms arising from the shift of the double bond from one atom to another. But this problem and the closely related problem of the structure of aromatic nuclei demand a detailed discussion, perhaps along the lines indicated, before they can be considered to be solved. 

Attempts to achieve optical induction during the reduction of aromatic ketones to the secondary alcohol by immobilising a single layer of chiral catalyst on a solid electrode surface have been much less successful. The preparation of such coatings... 

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