How does cadmium form complex ions with ammonia?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Periodic table — zinc group element Modern version of the periodic table of the elements (printable).

Cadmium, a member of the zinc group elements, forms complex ions by interacting with ligands—atoms, ions, or molecules that donate electrons to a central metal ion.

In the case of ammonia ( $N H_{3}$ ), cadmium reacts to form the complex ion with the formula $[C d (N H_{3})_{4}]^{2 +}$ . This process involves the donation of electron pairs from the ammonia molecules to the central cadmium ion, which typically exists in the +2 oxidation state in its compounds.12

While cadmium compounds are primarily ionic, the formation of such complexes demonstrates the element's ability to engage in coordination chemistry, similar to other transition metals.1