Tanabe-Sugano diagrams tetrahedral complexes

Tanabe-Sugano diagrams with representative values of C/B are given in Figures 12-15 for the lower lying terms of each of the cF configurations, n = 1-5. They can be used to deduce the principal features to be expected of the spectra of complexes of all the first transition metal ions in approximate octahedral or tetrahedral stereochemistry. 

Fig. 2. Tanabe-Sugano diagram for octahedral d8-complexes and tetrahedral d2-complexes. Notation as in Fig. 1.

Since the Tanabe-Sugano diagrams for d5-systems are symmetric with respect to octahedral and tetrahedral complexes, one can strictly speaking only determine the numerical value A. However, the choice of examples in Table 3 clearly demonstrates that the manganese (II) aqua ion is Mn(H20)g++ and not Mn(HaO)4++. 

The Tanabe-Sugano diagram for a d complex with tetrahedral symmetry is equivalent to the Tanabe-Sugano diagram for a d " complex with octahedral symmetry. The important questions that must be considered are (i) What molecular orbital does the fourth metal d-electron populate in complexes with octahedral symmetry and (ii) What orbital does the third metal d-electron populate in complexes with tetrahedral symmetry The answers are (i) the d-orbital at lower energy is populated and electron pairing occins when... 

---