chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

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

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

s to produce amines (molecules containing a

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

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

s to produce

nitrides In chemistry, a nitride is an inorganic compound of nitrogen. The "nitride" anion, N3- ion, is very elusive but compounds of nitride are numerous, although rarely naturally occuring. Some nitrides have a find applications, such as wear-resistant ...

. 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. 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 haloalkane and conc. 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 can also undergo ammonolysis when in the presence of ammonia. An example is the conversion of phenol to aniline, catalyzed by stannic chloride. ROH + NH3 A -> nCl4 RNH2 + H20

Of Carbonyl Compounds

The reaction between a ketone and ammonia results in an ammine and by product water. This reaction is water sensitive and thus drying agents such as aluminum chloride or dean-stark apparatus 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: RCOR + NH3 <=> RCNR + H2O .

Inorganic synthesis

Ammonolysis can be used to synthesized nitrides (and oxynitrides) 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 (substra ...

, 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 crystallizing substances from high-temperature aqueous solutions at high vapor pressures; also termed "hydrothermal method". The term "hydrothermal" is of geologic origin. Geochemists an ...

). 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

Chemical reactions Ammonia {{reaction-stub