Question

Why do coordination compounds have color?

Answer 1

Coordination Compounds - Those substances in which a central metal atom is surrounded by nonmetal atoms or a group of atoms, called ligands, joined to it by chemical bonds.

1. Different ligands have different effects on the central ion energy of the d-orbitals.
2. Transition metals impart color to the following coordination compounds because of the presence of half-filled or fully-filled d-orbitals.
3. Valance Bond Theory determines the magnetic behavior of the compounds whether diamagnetic or paramagnetic and the presence of unpaired electrons.
4. Thus, according to CFSE, the division of the d-orbital involves the splitting of the d-orbital into a higher and lower orbital and determines the colour of the coordination compounds.
5. The more energy is required to promote an electron from the lower group of orbitals to the higher ones, the greater the break. Higher energy refers to shorter wavelengths in terms of the color of the light absorbed.