The ‘g’ subscript is used for complexes with a center of symmetry, which octahedral and square planar complexes possess. Tetrahedral complexes lack symmetry, so the ‘g’ subscript is not used in their energy level designations.

The orbital splitting energies (∆ₜ) in tetrahedral coordination entities are not large enough to force electron pairing, resulting in low spin configurations. The relationship is given by ∆ₜ = (4/9) ∆₀ for the same metal, ligands, and metal-ligand distances.

The distribution of the fourth electron in d⁴ ions depends on the relative magnitudes of crystal field splitting (∆₀) and pairing energy (P). The two possible patterns are either pairing with an existing electron in the t₂g level or avoiding ...

In octahedral coordination entities, the single d electron occupies the lower energy t₂g orbital. For d⁴ ions, the fourth electron can either pair with an existing electron in the t₂g level or occupy the higher energy eg level, depending on ...

The spectrochemical series is an experimentally determined sequence based on the absorption of light by complexes with various ligands. It provides insights into the ligand’s ability to cause crystal field splitting.