The d Orbitals in a Tetrahedral Field

The splitting parameter in a tetrahedral field is denoted by Aj.= 10 Dq, so the e orbitals are stabilized with 3/5 Ar or 6Dq, and the t, orbitals increase in energy with 2/5 At or 4Dq. 

The splitting parameter Ap is always smaller than the parameter A because the ligand number is smaller, and the ligands are not pointed toward the direction of electronic density of the d orbitals  

The minus sign indicates that the splitting is reversed in the two geometries. 

Crystal field stabilization energy is a factor that contributes to the thermodynamic stability of complexes with predominantly ionic metal-ligand interactions, and also to the variation in properties of d metals and their compounds. Some of these properties are the size of di- and trivalent ions, hydration enthalpies, lattice energies, and stability of oxidation states. 

FIC U RE 3.9 Crystal field splitting of d orbitals of central ion in complexes with geometries  

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Similar energy level diagrams may be drawn for dn systems in tetrahedral crystal fields. There is an interesting relationship between these and the ones for certain systems in octahedral fields. We have already seen that the splitting pattern for the d orbitals in a tetrahedral field is just the inverse of that for the d orbitals in an octahedral field. A similar inverse relationship exists between the energy level diagrams of dn systems in tetrahedral and octahedral fields. The components into which each Russell-Saunders state is split are reversed in their energy order in the tetrahedral compared to the octahedral... 

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