Graphite intercalation compounds electronic structure

Attempts to elucidate the bonding have concentrated mainly on graphite-FeCla- This intercalate is especially suitable as a model compound, because the magnetic and Mossbauer properties of the iron nucleus constitute excellent probes for electronic structure and environment of the latter. 

Holzwarth, N. A. W. 1992. Chapter 2 Electronic band structure of graphite intercalations compounds. In Zabel, H. and S. A. Solin (eds.), Graphite Intercalation Compounds II, pp. 7-52, Springer-Verlag, Berlin. 

Hoffman, D. M., R. E. Heinz, G. L. Doll, and P. C. Eklund. 1985. Optical reflectance study of the electronic structure of acceptor-type graphite intercalation compounds. Phys. Rev. B 32 1278-1288. 

Ohno, T. 1980. Electronic band structure of lithium-graphite intercalation compound C6Li../. Phys. Soc. Jpn. 49(Suppl. A) 899-902. 

Tatar, R. C. 1985. A theoretical study of the electronic structure of binary and ternary first stage alkali intercalation compounds of graphite. PhD Thesis, University of Pennsylvania, PA. 

Alkali metals and bromine react with graphite to form solids known as intercalation compounds, where the foreign atoms are inserted between the intact graphite layers. Many other layered solids, for example dichalcogenides such as TaS2, which have structures similar to Cdl2 will also for intercalation compounds. The inserted species may be alkali metals, or electron donor molecules such as amines or organometallic compounds. 

J. E. Fisher, Electronic Properties of Graphite Intercalation Compounds in Physics and Chemistry of Materials with Layered Structures, ed. F. Levy, Reidel, Dordrecht, Holland, 1977, Vol. 5, in the press L. B. Ebert and H. Selig in Abstracts of Franco-American Conference on Intercalation Compounds of Graphite, May 23—27, La Napoule, France. 

The structure of the intercalates are of considerable interest, in that the intercalate material enters the graphite layers to form in the final analysis, a one-to-one graphite-intercalate layer structure. Intermediate compounds involve inclusion of the material in, for example, a second, fourth, or fifth layer rather than dilution of the amount in the same layer. The chemical bonding in the compounds appears to be ionic and certainly involves electron transfer probably, for example, from potassium to the upper pi-band of graphite. ... 

Carbon atoms crystallize in several forms. Graphite and diamond are well known carbon polymorphs. Fullerenes, which were discovered in the 1980 s, have also been well characterized. Carbon materials show a variety of different physical and chemical properties. Because of this the electronic structure of carbon materials has been investigated using a number of different experimental techniques, for example, XPS, UPS and XANES. Theoretical studies of carbon materials have been also performed. However, experimentally observed spectra are not always consistent with theoretical predictions. Recently, in order to understand the various kinds of observed electronic spectra, DV-Xa calculations have been performed on a small cluster model. [1] In the present paper, we report results of DV-Xa calculations performed on the carbon materials graphite, alkali graphite intercalation compounds (GIC), fullerene, and fluorinated fullerenes. 

Graphite Intercalation Compounds.— The reactions of graphitizable carbons leading to the formation of graphite intercalation compounds have been reviewed. Emphasis was placed on the insertion of alkali metals (Na), halogens (Brg), and acids (H2SO4). The effects of electronic structure and electron exchange on intercalation reactions were also considered. 

K. Kahicki and A.W. Morawski [4-7] studied the K-graphite-Fe catalysts derived from FeCl,-graphite intercalation compounds and frirther activation with vapour of metalUc potassium. The high activity of K-graphite-Fe catalysts at pressure of 10 MPa we attributed to presence of K-C-Fe sites where 2s electron is taken by graphite Jt-electron system and is transported also towards iron. Such "electronegatively enriched" graphite framework simultaneously plays a role as an "electronic" and "structural" promoter of iron. 

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