How ligands are classified ? Explain with suitable examples.

Explanation

Ligands can be classified into the following types depending upon the number of donon atoms in the ligands.
(a) Mono or unidentate ligands : Having only one donor atom. For example : `NH_(3)` nitrogen, is the only donon atom.
(b) Poly or multidenate ligands : Having two ro more donor atoms.
For example : Ethylene diamine (en)
`underset("two")overset(**)(NH_(2))underset("donor")(CH_(2))-underset("atoms")(CH_(2))overset(**)(NH_(2))`
`["EDTA"]^(4-)` is Ethylenediamine tetra acetate six donor atoms
(c) Ambident ligands: If a ligand had two or more donor atoms, while when a complex is formed only one donor atom is attached to the metal then it is called ambidentate ligand.
For example, `NO_(2)` has donor atom N and O out of the two only one donor atom is is linked to the metal as M-ONO or `MNO_(2)`.