Ammine

Template:Infobox chemical compound Ammine refers to a class of coordination complexes in which ammonia (NH₃) is a ligand. These complexes are typically formed with transition metals and are an important subset of coordination chemistry. Ammine complexes are notable for their stability and their role in various chemical reactions and industrial processes.

Structure and Bonding

In ammine complexes, ammonia acts as a Lewis base, donating its lone pair of electrons to form a coordinate covalent bond with a metal center. The general formula for these complexes is [M(NH₃)_n]^m+, where M represents the metal, n is the number of ammonia ligands, and m is the charge on the complex. The geometry of these complexes can vary, with common structures including octahedral, tetrahedral, and square planar arrangements.

Synthesis

Ammine complexes are typically synthesized by the direct reaction of ammonia with a metal salt in an aqueous solution. For example, the synthesis of hexamminecobalt(III) chloride involves the reaction of cobalt(II) chloride with ammonia in the presence of an oxidizing agent.

Properties

Ammine complexes exhibit a range of properties depending on the metal center and the number of ammonia ligands. These properties include varying degrees of solubility in water, different colors, and distinct magnetic properties. Many ammine complexes are also known for their stability, which makes them useful in various applications.

Applications

Ammine complexes have several important applications in chemistry and industry. They are used as catalysts in various chemical reactions, in the purification of metals, and in the synthesis of other coordination compounds. One notable application is the use of ammine complexes in the Haber process for the synthesis of ammonia.

Examples

Some well-known ammine complexes include:

• Hexamminecobalt(III) chloride ([Co(NH₃)_6]Cl₃)
• Tetraamminecopper(II) sulfate ([Cu(NH₃)_4]SO₄)
• Diamminesilver(I) chloride ([Ag(NH₃)_2]Cl)

See also

• Coordination chemistry
• Ligand
• Transition metal
• Haber process
• Catalysis