Title: Sodium Amide
CAS Registry Number: 7782-92-5
Synonyms: Sodamide
Molecular Formula: H2NNa
Molecular Weight: 39.01
Percent Composition: H 5.17%, N 35.91%, Na 58.93%
Line Formula: NaNH2
Literature References: Prepd from sodium metal and gaseous ammonia (or liq ammonia with ferric nitrate catalyst): Dennis, Browne,
Inorg. Synth. 1, 74 (1939); Greenlee, Henne,
ibid. 2, 128 (1946); Schenk in
Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 465-468. Alternate method: Bergstrom,
Org. Synth. coll. vol. III, 778 (1955).
Properties: Crystals, mp 210°. The commercial product may be a white to olive-green solid with sea-shell fracture. Begins to volatilize at 400° and dec into its elements between 500 and 600°. Heat of formation of solid (18°; 1 atm): -32.26 kcal/mole. Heat of soln (21°): -31.06 kcal/mole. Soly in liq ammonia at 20° = about 0.1%. Reacts violently with water forming NaOH and NH3. The reaction with alcohol is considerably slower. Should be stored in sealed containers which prevent all contact with air during storage: Bergstrom, Fernelius,
Chem. Rev. 12, 63, 75, 78 (1933). When exposed to the atmosphere, sodium amide rapidly absorbs H2O and CO2. When only limited absorption takes place, as in poorly sealed containers, products are formed which render the resulting mixture highly explosive. The formation of oxidation products is accompanied by the development of a yellow or brownish color. If such a change is noticed, the substance should be destroyed at once. This is conveniently accomplished by covering with much benzene, toluene, or kerosene and slowly adding dil ethanol with stirring.
Melting point: mp 210°
CAUTION: Intensely irritating to skin, eyes, mucous membranes.
Use: Dehydrating agent. In the production of indigo and hydrazine. Intermediate in the prepn of sodium cyanide. In ammonolysis reactions, in Claisen condensations, alkylation of nitriles and ketones, synthesis of ethynyl compds, acetylenic carbinols. Fused NaNH2 dissolves metallic Mg, Zn, Mo, W, quartz, glass, silicates and other substances.
