## Crystal Field Splitting and the F Orbitals

Colleagues,

I love crystal field theory, but I would like to try and extend this idea to the f-orbitals. We know how the d-orbitals split in an a variety of environments, but how do the f orbitals split? I want to develop an assignment for my students where they can use their knowledge from the d-orbitals to think about how the f-orbitals would split. Any ideas? I know CFT is not as important for the lanthanides, but I think it could be an interesting extension to what students typically learn about CFT.

Chip, yep this is a challenging question. I need to find a geometry as a starting point and go from there. I will work on some ideas.

Sibrina

Dear Fellow Vipers,

I have to concur with Dr. Stewart. The f orbits of the lanthanides are notoriously insensitive to ligand effects. It would actually be interesting to demonstrate this property by showing how d-splitting can change the fluorescent properties of transition metals through ligand metal interactions, while ligands do not significantly modulate the fluorescence of the lanthanides.

Sincerely

Cliff

Dear Colleagues,

Thanks for the great dialog! Maybe my conversation with my students should be why CFT doesn't work for the f-orbitals? (smile) Joanne, let me know what you find.

Sibrina

Ok, I have found some good internet resources on the topic, showing how the f-orbitals split in an octahedral environment. See the link below that could be used to extend the discussions on CFT. Let me know your thoughts on this resource.

http://wwwchem.uwimona.edu.jm:1104/courses/OctCFT_FOrbs.html

Sibrina

There are 2 parts to this question... the theoretical predictions, from symmetry, and the actual results, from experiment. You could certainly predict a splitting of the f-orbitals given a geometry. Whether it means anything.... I'll leave that to a real Ln/Ac chemist.

Another problem is that there are at least 2 "simple" ways to represent the f-orbitals, and they may have different symmetries. I know there is a J. Chem. Educ. article (I think; maybe IC) on this topic (conveniently in my office 5000 miles away) written before 1993, but I can't find it right now. One way was more axial and one way was oriented differently with more tori, I think.

I found a possibly useful article by Kettle, who is one of my favorite bonding theory authors anyway!

S. F. A. Kettle and A. J. Smith,

, 1967, 688-692,J. Chem. Soc. ADOI:10.1039/J19670000688Thanks Adam!

Sibrina Collins, PhD College of Wooster

You can find your answer in the book entitled with : "ligand field theory and it's applications" by the Authors: B. N. Figgis and M. A. Hitchman published by wiley-VCH.

the chapter 4 of this book explain it.