This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009)

Ball-and-stick model of the tetraamminecopper(II) cation, [Cu(NH₃)₄]²⁺.

In coordination chemistry an ammonia ligand is called an ammine. In contrast to alkyl amines it is spelled with a double "m". Cobalt(III) salts frequently actually contain hexaamminecobalt(III) (e.g. hexaamminecobalt(III) chloride, [Co(NH₃)₆]Cl₃). Tetraamminedichlorochromium(III) chloride, [Cr(NH₃)₄Cl₂]Cl, has the unique property that the cis isomer is violet and the trans isomer is green. Tetraamminecopper(II), [Cu(NH₃)₄]²⁺, is a much deeper blue than the bare copper ion. Formation of the diamminesilver ion, [Ag(NH₃)₂]⁺, allows the generally insoluble silver chloride to dissolve in aqueous ammonia.