Write the electronic configuration for d4 ion if /0 < P on the basis of...

Write the electronic configuration for d4 ion if /0 < P on the basis of crystal field theory.

Ans.

In crystal field theory, the electronic configuration of transition metal ions can be determined by considering the number of d-electrons and the nature of the ligand field they experience.

For a d^4 ion, we’ll consider the case where the ligand field strength is weak, which is often the case for transition metal ions with small ligands or in high oxidation states.

The d^4 configuration implies that there are 4 electrons in the d orbitals. According to the Aufbau principle, these electrons fill the d orbitals from lowest to highest energy levels based on Hund’s rule.

In a weak field, such as when ligands have weak crystal field splitting, the pairing energy required to pair electrons in the d orbitals becomes higher than the energy difference between the t2g and eg levels. As a result, the electrons tend to occupy the t2g orbitals before pairing up.

For a d^4 ion in a weak crystal field, the electronic configuration would be:

t2g^4 eg^0

This configuration signifies that all 4 electrons occupy the lower energy t2g orbitals, and none are in the higher energy eg orbitals. The electrons in the t2g orbitals experience lower energy due to weaker crystal field splitting, making it more favorable for them to occupy these orbitals before pairing up.

So, in the context of crystal field theory, for a d^4 ion with weak ligand field, the electronic configuration is t2g^4 eg^0.