What determines the magnitude of the energy gap ($\Delta$) induced in a transition metal complex?

Answer

The identity of the surrounding ligands and the complex geometry

The energy splitting ($\Delta$) is highly sensitive to the surrounding chemical environment, specifically the identity of the ligands, which are ordered empirically in the spectrochemical series, and the three-dimensional geometry.

What determines the magnitude of the energy gap ($\Delta$) induced in a transition metal complex?

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