Write a note on chelating ligands.

(N/A) When a polydentate ligand coordinates to a metal ion,forming a five- or six-membered closed ring structure that includes the metal ion,it is called a chelating ligand,and the phenomenon is known as chelation. The resulting compounds are known as chelates.
Chelates are highly stable. The stabilization of coordination compounds due to chelation is called the chelate effect.
For example: $[Pt(en)_2]^{2+}$
In the above example,the bidentate ligand ethylene diamine $(en)$ forms a five-membered closed ring structure with the central metal ion $Pt^{2+}$.