CBSE Class 12-science Answered
Explain classification of ligands on the basis of charge and dentisity. Explain the ambidentate ligands following terms with example.
- Denticity: The number of ligating (linking) atoms present in a ligand is called denticity.
- Unidentate ligands: The ligands whose only donor atom is bonded to a metal atom are called unidentate ligands.
- Examples: H2O, NH3, CO, CN−
- Didentate ligands: The ligands which contain two donor atoms or ions through which they are bonded to the metal ion.
- Example: Ethylene diamine (H2NCH2CH2NH2) has two nitrogen atoms, and oxalate ion has two oxygen atoms which can bind with the metal atom.
- Polydentate ligand: When several donor atoms are present in a single ligand, the ligand is called a polydentate ligand.
- Example: In N(CH2CH2NH2)3, the ligand is said to be polydentate. Ethylenediaminetetraacetate ion (EDTA4–) is an important hexadentate ligand. It can bind through two nitrogen and four oxygen atoms to a central metal ion.