Chelating ligands

Definition

Chelating ligands are molecules that can form multiple bonds to a single metal ion, creating a ring structure. They increase the stability of coordination compounds through the chelate effect.

5 Must Know Facts For Your Next Test

1. Chelating ligands typically have two or more donor atoms that bind to a central metal ion.
2. The stability of a coordination complex increases with the number of rings formed by chelating ligands.
3. Ethylenediamine (en) and EDTA are common examples of chelating ligands.
4. Chelate complexes are generally more stable than complexes with monodentate ligands due to entropy considerations.
5. Chelation therapy uses chelating agents to remove heavy metals from the body.

Review Questions

• What is the significance of the chelate effect in coordination chemistry?
• Give two examples of common chelating ligands and describe their structure briefly.
• Why are chelate complexes usually more stable than those with monodentate ligands?

Related terms

Coordination Complex: A structure consisting of a central metal atom or ion bonded to surrounding molecules or ions called ligands.

Monodentate Ligand: A ligand that forms a bond with a central metal atom/ion through only one donor atom.

Bidentate Ligand: A ligand that has two donor atoms which can simultaneously bond to a central metal ion, forming at least one ring.