4.2 Crystal-Field Theory

This lesson will build on your understanding of how transition metal complexesAre combinations of a metal center and ligands. They are denoted by the use of square brackets [ ]. The central metal atom is always named first. This is sometimes followed by the ligands. Outside the square brackets any counterions or the charge of the complex is listed. form and introduce concepts explaining how the electrons and the orbitals behave when a transition metal gets coordinated by ligands. This behaviour ultimately decides what shape the complex will adopt.

Bonding in Transition Metal Complexes

Now that you have an understanding of transition metal complexes, we are going to look at how the orbitals that you learned about in Module 2. Physical Chemistry dictate the geometry that such complexes adopt.

The theory we use to understand the bonding in transition metal complexes is called crystal-field theory. In this theory, we make the assumption that the bonding between the metal and ligands is purely ionic. We also assume that the transition metal centre is a point of positive charge in the centre of the complex, and that the ligands surrounding it are points of negative charge.