Lecture #30
  CURMUDGEON GENERAL'S WARNING. These "slides" represent highlights from lecture and are neither complete nor meant to replace lecture. It is advised not to use these as a reliable means to replace missed lecture material. Do so at risk to healthy academic performance in 09-105.
Lecture Outline Transition Metal Complexes

Binding in transition metal complexes

Ni(CO)42+ is our last illustration.
The arrangement which is consistent with the observed properties of the complex (geometry and magnetic properties) and other complexes similar to it arises from use of four Ni orbitals that hybridize to give dsp2 hybrids. Although we have not discussed this combination before, it does correspond to four equal orbitals arranged in a square planar distribution.
(This was not included from an earlier lecture.) Here's another attempt to show how crystal field splitting works, but with coordination number 2, also known as linear geometry.
This orbital's electron, pointing directly at the ligands (with their electrons) is raised in energy.
On the other hand, this orbital does not point towards the ligands and is unaffected by their presence. Likewise for the dxy.
A review problem for stimulating thought and discussion. It will take several steps to work through. It is much too long and complex to worry about as a possible exam question.
Practice problem
Practice problem