chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

, ammonolysis (/am·mo·nol·y·sis/) is the process of splitting ammonia into NH2- + H+. Ammonolysis reactions can be conducted with

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

s to produce amines (molecules containing a

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

atom with a

lone pair In chemistry, a lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bondIUPAC ''Gold Book'' definition''lone (electron) pair''/ref> and is sometimes called an unshared pair or non-bonding pair. Lone ...

, :N), or with

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

s to produce

nitrides In chemistry, a nitride is a chemical compound of nitrogen. Nitrides can be inorganic or organic, ionic or covalent. The nitride anion, N3−, is very elusive but compounds of nitride are numerous, although rarely naturally occurring. Some nitr ...

. This reaction is analogous to

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

in which water molecules are split. Similar to water, liquid ammonia also undergoes auto-ionization, , where the rate constant is k = 1.9 × 10⁻³⁸. Organic compounds such as alkyl halides, hydroxyls (hydroxyl nitriles and carbohydrates), carbonyl (aldehydes/ketones/esters/alcohols), and sulfur (sulfonyl derivatives) can all undergo ammonolysis in liquid ammonia.

Organic synthesis

Mechanism: Ammonolysis of Esters

This mechanism is similar to the hydrolysis of esters, the ammonia attacks the electrophilic carbonyl carbon forming a

tetrahedral intermediate A tetrahedral intermediate is a reaction intermediate in which the bond arrangement around an initially double-bonded carbon atom has been transformed from trigonal to tetrahedral. Tetrahedral intermediates result from nucleophilic addition to a c ...

. The reformation of the C-O double bond ejects the ester. The alkoxide deprotonates the ammonia forming an alcohol and amide as products. Ammonolysis mechanism

Of haloalkanes

On heating a

haloalkane The haloalkanes (also known as halogenoalkanes or alkyl halides) are alkanes containing one or more halogen substituents of hydrogen atom. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalka ...

and concentrated ammonia in a sealed tube with ethanol, a series of amines are formed along with their salts. The tertiary amine is usually the major product. : This is known as Hoffmann's ammonolysis.

Of alcohols

Alcohols In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a Saturated and unsaturated compounds, saturated carbon atom. Alcohols range from the simple, like methanol and ethanol ...

can also undergo ammonolysis when in the presence of ammonia. An example is the conversion of

phenol Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire. The molecule consists of a phenyl group () ...

aniline Aniline (From , meaning ' indigo shrub', and ''-ine'' indicating a derived substance) is an organic compound with the formula . Consisting of a phenyl group () attached to an amino group (), aniline is the simplest aromatic amine. It is an in ...

, catalyzed by

stannic chloride Tin(IV) chloride, also known as tin tetrachloride or stannic chloride, is an inorganic compound of tin and chlorine with the formula SnCl4. It is a colorless hygroscopic liquid, which fumes on contact with air. It is used as a precursor to other t ...

. :ROH + NH3 A -> ce RNH2 + H2O

Of carbonyl compounds

The reaction between a

ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( ...

and ammonia results in an

imine In organic chemistry, an imine ( or ) is a functional group or organic compound containing a carbon–nitrogen double bond (). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bon ...

and byproduct water. This reaction is water sensitive and thus drying agents such as

aluminum chloride Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms a hexahydrate with the formula , containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are col ...

or a

Dean–Stark apparatus upDean–Stark apparatus setup for an azeotrope with a solvent whose density is ''less than'' that of water: The Marcusson apparatus, Dean-Stark apparatus, Dean–Stark receiver, distilling trap, or Dean–Stark Head is a piece of laboratory gl ...

must be employed to remove water. The resulting imine will react and decompose back into the ketone and the ammonia when in the presence of water. This is due to the fact that this reaction is reversible: :R2CO + NH3 <=> R2CNH + H2O .

Inorganic synthesis

Ammonolysis can be used to synthesize

(and

oxynitride The oxynitrides are a group of inorganic compounds containing oxygen and nitrogen not bound to each other, instead combined with other non-metallic or metallic elements. Some of these are oxosalts with oxygen replaced by nitrogen. Some of these co ...

s) by reacting various metal precursors with ammonia, some options include

chemical vapor deposition Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (electro ...

, treating metals or metal oxides with ammonia gas, or liquid supercritical ammonia (also known as "ammonothermal" synthesis, analogous to

hydrothermal synthesis Hydrothermal synthesis includes the various techniques of synthesizing substances from high-temperature aqueous solutions at high pressures; also termed "hydrothermal method". The term "hydrothermal" is of geologic origin. Geochemists and mine ...

). :M + NH3 -> MN + 3/2 H2 :MO2 + 4/3 NH3 -> MN + 2 H2O + 1/6 N2 The products of these reactions may be complex, with mixtures of oxygen, nitrogen, and hydrogen that can be difficult to characterize.

References

{{Reflist Ammonia Biochemical reactions