Question

Write postulates of Werner’s theory of coordination complexes. Write the name of a hexadentate ligand.

Hint:

Werner's theory provides a fundamental understanding of the structure and bonding within coordination complexes by differentiating between primary and secondary valencies.

Answer 1

Key Principles of Werner’s Coordination Theory:

1. Primary valencies reflect the oxidation state of the metal and are typically ionizable.
2. Secondary valencies define the coordination number of the metal and are generally not ionizable.
3. Metal ions fulfill their secondary valencies by establishing coordinate bonds with ligands.
4. The arrangement of ligands around the metal ion is structured in specific geometries based on the nature of the bonds.

Example of a Hexadentate Ligand:
Ethylenediaminetetraacetate (EDTA), a hexadentate ligand, effectively coordinates with metal ions using its six donor atoms, forming strong complex ions. \[ \text{EDTA}^{4-} \]