Assessing the contribution of d orbitals

In Section 10.8, we shall see the need to include d orbitals in the description of bonding between d-metal ions, such as Fe +, and proteins, such as hemoglobin. To get a sense of how molecular orbitals can be built from d orbitals, show how they can contribute to the formation of a and n orbitals in diatomic molecules. 

Strategy We need to assess the symmetry of d orbitals with respect to the internuclear z-axis orbitals of the same symmetry can contribute to a given molecular orbital. 

Solution A d 2 orbital has cylindrical symmetry around z and so can contribute to a orbitals. The and dy orbitals have % symmetry with respect to the axis (Fig. 10.25), so they can contribute to n orbitals. 

I Self-test 10.5) Sketch the 5 orbitals (orbitals that resemble four-lobed d orbitals when viewed along the internuclear axis) that maybe formed by the remaining two d orbitals (and which contribute to bonding in some d-metal cluster compounds). Give their inversion-symmetry classification. 

Once we have constructed the molecular orbitals, we build up the ground-state electron configuration as follows  

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