Question

The correct order of the energy of the d orbitals of a square planar complex is

• A. \(d_{xz}=d_{yz}<d_{xy}<dz^2<d_{x^2-y^2}\)
• B. \(d_{xz}=d_{yz}<d_{z^2}<d_{xy}<d_{x^2-y^2}\)
• C. \(d_{yz}<d_{xz}<d_{z^2}<d_{xy}<d_{x^2-y^2}\)
• D. \(d_{xy}<d_{xz}<d_{yz}<d_{x^2-y^2}<d_{z^2}\)

Answer 1

The Correct Option is B

To determine the correct order of energy levels for the d orbitals in a square planar complex, it is important to understand the geometry and electron configuration involved.

Square planar complexes are typically formed by d⁸ metal ions. In such complexes, there is a distinct splitting of the d orbitals due to the ligand field effect. 

The splitting pattern of d orbitals in a square planar complex is primarily influenced by both the nature of ligands and the metal center. However, the typical energy order of the d orbitals when influenced by the ligand field is:

1. The \(d_{x^2-y^2}\) orbital experiences the highest energy because it points directly towards the surrounding ligands on the x and y axes.
2. The \(d_{xy}\) orbital has lesser energy than \(d_{x^2-y^2}\) because it is in the plane but not directly facing the ligands.
3. The \(d_{z^2}\) orbital is next, as it is oriented along the z-axis, further from the ligand plane, leading to less direct interaction with ligands.
4. Lastly, the \(d_{xz}\) and \(d_{yz}\) orbitals have the lowest energy because they are oriented between the ligand axes, leading to minimal direct overlap.

Therefore, the order of increasing energy is:

\(d_{xz}=d_{yz}<d_{z^2}<d_{xy}<d_{x^2-y^2}\)

This matches the correct answer: \(d_{xz}=d_{yz}<d_{z^2}<d_{xy}<d_{x^2-y^2}\).

All other options do not correctly represent the energy ordering of d orbitals in a square planar complex, validating our correct option choice. For example:

• The option \(d_{xz}=d_{yz}<d_{xy}<dz^2<d_{x^2-y^2}\) incorrectly places \(d_{z^2}\) below \(d_{xy}\).
• The option \(d_{yz}<d_{xz}<d_{z^2}<d_{xy}<d_{x^2-y^2}\) incorrectly separates \(d_{xz}\) and \(d_{yz}\).
• The option \(d_{xy}<d_{xz}<d_{yz}<d_{x^2-y^2}<d_{z^2}\) gives an incorrect overall sequence.