Graphite intercalation compound

compounds. It is customary to specify the composition together with the stage.

Potassium graphite is denoted as KC₈ and is one of the strongest reducing agents known. It is prepared under inert atmosphere by melting potassium over graphite powder. The potassium is absorbed into the graphite and a color change from black to bronze is observed. The resulting solid is also quite pyrophoric. Structurally, composition can be explained by assuming that the potassium to potassium distance is twice the distance between hexagons in the carbon framework. The bond between graphite and potassium atoms is ionic and the compound is electrically conductive. [ [http://physics.nist.gov/TechAct.2001/Div846/div846h.html NIST Ionizing Radiation Division 2001 - Technical Highlights ] ] .

Potassium graphite has also been used as a catalyst in polymerizations and as a coupling reagent for aryl halides to biphenyls .

In one study "Functionalization of Potassium Graphite", Soma Chakraborty, Jayanta Chattopadhyay, Wenhua Guo, and W. Edward Billups Angew. Chem. Int. Ed. 2007, 46, 4486 –4488 DOI|10.1002/anie.200605175] freshly prepared KC₈ is treated with "1-iodododecane" delivering a modification (micrometre scale carbon platelets with long alkyl chains sticking out providing solubility) that is soluble in chloroform. Another potassium graphite compound, KC₂₄, has been used as a neutron monochromator.

Carbon monofluoride is denoted as (CF)_x and used as a cathode material in a type of lithium batteries. It is prepared by reaction of gaseous fluorine with graphitic carbon at 420-450 °F. The color is grayish, white, or yellow. The bond between the carbon and fluorine atoms is covalent. The compound is not electrically conductive.

Tetracarbon monofluoride is denoted as C₄F. It is prepared by reacting gaseous fluorine mixed with hydrogen fluoride with graphite at room temperature. The compound has blackish-blue color.

Other examples are graphite bisulfate and graphite oxide.

Examples of complex graphite intercalation compounds are those with barium and ammonia guests (Ba(NH₃)_2.5C_10.9(st.1)) or those with caesium, hydrogen and potassium (CsC₈.K₂H_4/3C₈(st.1)).

References

External links

* [http://www.cci.ethz.ch/experiments/K-Graph_darst/en/stat.html Preparation of Potassium Graphite]