*** Welcome to piglix ***

Sodium amide

Sodium amide
Structural formula of sodium amide
Ball and stick, unit cell model of sodium amide
Names
IUPAC name
Sodium amide, sodium azanide
Other names
Sodamide
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.029.064
EC Number 231-971-0
PubChem CID
UN number 1390
Properties
NaNH2
Molar mass 39.01 g mol−1
Appearance Colourless crystals
Odor ammonia-like
Density 1.39 g cm−3
Melting point 210 °C (410 °F; 483 K)
Boiling point 400 °C (752 °F; 673 K)
reacts
Solubility 0.004 g/100 mL (liquid ammonia), reacts in ethanol
Acidity (pKa) 38 (conjugate acid)
Structure
orthogonal
Thermochemistry
66.15 J/mol K
76.9 J/mol K
-118.8 kJ/mol
-59 kJ/mol
Hazards
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g., fluorine Special hazard W: Reacts with water in an unusual or dangerous manner. E.g., cesium, sodiumNFPA 704 four-colored diamond
Flash point 4.44 °C (39.99 °F; 277.59 K)
450 °C (842 °F; 723 K)
Related compounds
Other anions
Sodium bis(trimethylsilyl)amide
Other cations
Potassium amide
Related compounds
 Ammonia
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

Sodium amide, commonly called sodamide, is the inorganic compound with the formula NaNH2. This solid, which is dangerously reactive toward water, is white, but commercial samples are typically gray due to the presence of small quantities of metallic iron from the manufacturing process. Such impurities do not usually affect the utility of the reagent. NaNH2 conducts electricity in the fused state, its conductance being similar to that of NaOH in a similar state. NaNH2 has been widely employed as a strong base in organic synthesis.

Sodium amide can be prepared by the reaction of sodium with ammonia gas, but it is usually prepared by the reaction in liquid ammonia using iron(III) nitrate as a catalyst. The reaction is fastest at the boiling point of the ammonia, c. −33 °C. An electride, [Na(NH3)6]+e−, is formed as a reaction intermediate.

NaNH2 is a salt-like material and as such, crystallizes as an infinite polymer. The geometry about sodium is tetrahedral. In ammonia, NaNH2 forms conductive solutions, consistent with the presence of Na(NH3)6+ and NH2− ions.

Sodium amide is mainly used as a strong base in organic chemistry, often in liquid ammonia solution. It is the reagent of choice for the drying of ammonia (liquid or gaseous). One of the main advantages to the use of sodamide is that it is rarely functions as a nucleophile. In the industrial production of indigo, sodium amide is a component of the highly basic mixture that induces cyclisation of N-phenylglycine. The reaction produces ammonia, which is recycled typically.


Sodium amide induces the loss of two equivalents of hydrogen bromide from a vicinal dibromoalkane to give a carbon-carbon triple bond, as in a preparation of phenylacetylene. Usually two equivalents of sodium amide yields the desired alkyne. Three equivalents are necessary in the preparation of a terminal alkynes because the terminal CH of the resulting alkyne protonates an equivalent amount of base.


...
Wikipedia

...