Question

Why do d-block elements form complexes?

Answer 1

1. Transition elements form complexes readily because of the small size of the ions and higher nuclear charge, they possess high charge density.
2. Due to the presence of vacant d-orbitals in which a ligand can donate its electron, forms a complex.
3. Transition metal ions have a large polarizing power as a result they can attract lone pairs from other atoms to form complexes.
4. For example, elements like ${\mathrm{Fe}}^{+2}\mathrm{and}{\mathrm{Fe}}^{+3},{\mathrm{Cu}}^{+}\mathrm{and}{\mathrm{Cu}}^{+2}$ shows variable oxidation state and can form a large number of complexes.