What Is Sodium Amide?
Sodium amide is an inorganic compound consisting of a polymeric series of N-Na bonds.
It has an ammonia-like odor and a melting point of 210°C. It decomposes at about 500°C. Its chemical formula is NaNH2. Its chemical formula is NaNH2, and it is mainly used as a strong base in chemical synthesis. Its molecular mass is 30.01 and its CAS number is 7782-92-5. It is also known as “sodamide. At room temperature, it exists in solid form, colorless in its pure form and gray in its less pure form.
Sodium amide sold commercially appears gray because it contains iron as an impurity, but this does not affect its quality. It is tidily soluble and is hydrolyzed by oxygen in the air to sodium nitrite. Care must be taken when storing it, as it may be altered by light.
Uses of Sodium Amide
Sodium amide is used as a strong base in chemical synthesis because of its low nucleophilicity, and it can be used in situations where nucleophilic attack is to be avoided. However, due to its low solubility in ordinary organic solvents, it is mainly used in reactions in which liquid ammonia is used as a solvent.
Specifically, it is used in the reaction to form carbon-carbon bonds by de-protonating acetylene and using acetylene as a nucleophile. This reaction can be used to synthesize alkanes and alkenes by reducing the synthesized acetylene, and can also be used to synthesize carbonyl compounds by hydrolysis.
The benzaine reaction also uses the basicity of sodium amide to exchange substituents on the benzene ring by withdrawing hydrogen from the benzene ring to form benzaine. Other reactions include the synthesis of alkyl ketones and the titibabine reaction, which introduces an amino group on the carbon adjacent to the nitrogen atom of the pyridine ring.
Reactions carried out in organic solvents, such as lithium diisopropylamide (LDA), are often used. Apart from its use as a base, it is also used as a condensing agent and as a reducing agent for organic molecules.
Other uses include its use as a raw material for indigo, hydrazine, and sodium cyanide. Indigo is a dye and has been used to dye denim and jeans. Sodium amide by itself is also used as a desiccant and dehydrating agent to remove trace amounts of water in ammonia; in 2018, a reaction was reported in which mixing chloride and sodium amide can synthesize oxynitrides by an instantaneous temperature rise reaction.
Structure of Sodium Amide
The crystal structure of sodium amide is orthorhombic, with an alternating polymeric succession of nitrogen and sodium atoms.
It has a structure in which four nitrogen atoms are coordinated to one sodium atom,and is conductive when dissolved in liquid ammonia. Sodium amide dissolved in liquid ammonia is called ammono base. Ammono bases are characterized by their ability to dissolve metals such as magnesium, zinc, and molybdenum, as well as glass.
Properties of Sodium Amide
Sodium amide can be synthesized from metallic sodium and gaseous ammonia, but is usually synthesized from liquid ammonia using iron (III) nitrate as a catalyst. 38 It is a strong base because it has a high acid dissociation constant (pKa).
Other Information on Sodium Amide
Irritant Properties of Sodium Amide
Although not regulated by major national laws and regulations, sodium amide is a strong base compound that is highly irritating and can cause irritation to the skin. When handling, be sure to wear a lab coat, protective glasses, and gloves.
In addition, it should be stored in a dry environment because it reacts violently when exposed to water, producing sodium hydroxide and ammonia, a toxic gas. Particular attention should be paid to accidents that have occurred in the past where fire has been caused by contact with moisture; it is best to store at temperatures above 30°C (86°F).