Graphite, alkali ammine compounds

Prepared from graphite and alkali metal dissolved in liquid ammonia. 

About 2 g. of powdered or flake graphite and the stirring bar of a magnetic stirrer are introduced into vessel c,which has a fritted glass disc (Fig. 208). After careful drying of the apparatus 

Analysis. The contents of a weighed ampoule are placed in an Erlenmeyer flask containing 50-70 ml. of ice-cold 2N H3SO4. The decomposed product is boiled for one half hour and the graphite is filtered off and washed. The alkali is determined as sulfate in an aliquot of the filtrate KOH is added to another aliquot, and the NH3 is distilled off and determined by volumetric analysis. The dried graphite is treated as described for potassium graphite compounds. 

The compound approximates CiaM(NH3)g. Very dark blue, enlarged crystals. Very sensitive to air and moisture. The K, Rb and Cs compoimds can be stored indefinitely, but the Li and Na compounds decompose in a few days to amides, evolving H3. 

Riidorff, E. Schulze and O. Rubisch. Z. anorg. allg. Chem. 282, 232 (1955). 

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Reduction by Alkali Metals. This was the first reduction method successfully used it is particularly useful for reducing in liquid ammonia cyanides ( ), alkynyls (f 4 ), ammines (193) and ethylendiammines (192). The same reaction on phosphine compounds gives low yields because the reagents are insoluble in liquid ammonia (45). The zero valent nickel compounds with phosphites are obtained in good yield with the potassium graphite compound KCs (110). 

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