Main Page | See live article | Alphabetical index A complex ion is a polyatomic ion formed by a charged complex between one or more metal atoms associated through coordinate-covalent bonds to one or more non-metallic ligands. The ligands may, in turn, be either simple ions, polyatomic ions, or neutral polyatomic molecules. Complexation may alter the chemical properties of Ions, for example Cu2+ solved in water is light blue, and [Cu(NH3)4]2+ is dark blue. Silverchloride is (virtually) unsoluble in water. When Ammonia is added, it "vanishes" immediately: AgCl + 2 NH3 --> [Ag(NH3)2]+ + Cl- This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.