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XXXV.—Graphite Crystals and Crystallites. I. Binding Energies in Small Crystal Layers

Published online by Cambridge University Press:  14 February 2012

Mary Bradburn
Affiliation:
Royal Holloway College, London University
C. A. Coulson
Affiliation:
Wheatstone Physics Laboratory, King's College, London
G. S. Rushbrooke
Affiliation:
Chemistry Department, Leeds University

Summary

Calculations are made of the resonance energy, bond order and bond length in a series of graphitic layers of varying size. Carbon–carbon bond lengths appear to vary very little in size with increasing number of carbon atoms, in agreement with experiment. But variations in resonance energy are significant, and indicate clearly that resonance, by itself, favours an approximately square, rather than oblong, shape. But in the case of such layers in equilibrium in the presence of molecular hydrogen, the most stable layer containing a given number of carbon atoms is of the long, thin polyphenyl type. Some tentative calculations suggest that polymerisation of smaller groups to larger ones should be endothermic, in agreement with the experimental fact that the formation of larger graphitic crystallites during carbonisation occurs, with emission of hydrogen, only at high temperatures.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1946

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References

REFERENCES TO LITERATURE

Blayden, H. E., Gibson, J., and Riley, H. L., 1943. Proceedings of a Conference on the Ultra-fine Structure of Coals and Cokes, British Coal Utilisation Research Association.Google Scholar
Coulson, C. A., 1939. “Bonds of Fractional Order”, Proc. Roy. Soc., A, CLXIX, 413.Google Scholar
Coulson, C. A., 1941. “Quantum Theory of the Chemical Bond”, Proc. Roy. Soc. Edin., A, LXI, 115.Google Scholar
Coulson, C. A., 1944. “Structure of Coronene”, Nature, CLIV, 797.CrossRefGoogle Scholar
Coulson, C. A., and Rushbrooke, G. S., 1940. “Note on the Method of Molecular Orbitals”, Proc. Camb. Phil. Soc., XXXVI, 193.CrossRefGoogle Scholar
De Boer, J. H., 1940. “Atomic Distances in Small Graphite Crystals”, Receuil des Travaux Chim. des Pays-Bas, Lix, 826.CrossRefGoogle Scholar
Dewey, P. H., and Harper, D. R., 1938. “Heats of Combustion of Anthracite Cokes”, Journ. Nat. Bur. Standards, XXI, 457.CrossRefGoogle Scholar
Herzberg, G., 1937. “Heat of Sublimation of Graphite”, Chem. Rev., xx, 145.CrossRefGoogle Scholar
Jessup, R. S., 1938. “Heats of Combustion of Diamond and Graphite”, Journ. Nat. Bur. Standards, xxi, 475CrossRefGoogle Scholar
Lennard-Jones, J. E., and Coulson, C. A., 1939. “Structure and Energy of Hydrocarbon Molecules”, Trans. Faraday Soc., xxxv, 811.CrossRefGoogle Scholar
Mulliken, R. S., Rieke, C. A., and Brown, W. G., 1941. “Hyperconjugation”, Journ. Amer. Chem. Soc., LXIH, 41.CrossRefGoogle Scholar
Nelson, J. B., and Riley, D. P., 1945. “Thermal Expansion of Graphite”, Proc. Lond. Phys. Soc., LVII, 477.CrossRefGoogle Scholar
Pauling, L., 1939. “Nature of the Chemical Bond”, Cornell University Press.Google Scholar
Riley, H. L., 1939. “Chemistry of Solid Carbon”, Soc. Chem. Ind., LVlll, 391.CrossRefGoogle Scholar
Rutherford, D. E., 1947. “Some Determinants Arising in Physics and Chemistry”, Proc. Roy. Soc. Edin., A, LXII, 229.Google Scholar
Taylor, A., 1941. “Study of Carbon by Debye-Scherrer Method”, Journ. Set. Instr., XVIII, 91.Google Scholar
Taylor, H. S., Eyring, H., and Sherman, A., 1933. “Binding Energies in the Growth of Crystal Nuclei”, Journ. Chem. Phys., I, 68.CrossRefGoogle Scholar
Warren, B. E., 1941. “X-ray Diffraction in Random Layer Lattices”, Phys. Rev., LIX, 693.CrossRefGoogle Scholar
Wheland, G. W., 1934. “Quantum Mechanics of Unsaturated and Aromatic Molecules”, Journ. Chem. Phys., 11, 474.CrossRefGoogle Scholar
Wheland, G. W., 1942. “Resonance Energies of Aromatic and Unsaturated Molecules,” Journ. Amer. Chem. Soc., LXIV, 902.Google Scholar