(i) Role in biological systems: There are various essential coordination compounds in the bodies of animals, such as hemoglobin, which is an iron coordination compound.

In plants, chlorophyll pigment is a coordination compound of magnesium.

(ii) The use of coordinate compounds in medicinal chemistry: A large number of coordination compounds are employed for curative purposes. For example, cis-platin, a platinum coordination molecule, is used to inhibit the growth of tumors.