Electron Configuration of Mn +4: Explained and Simplified

[MichaelXY]

Homework Statement

I am a little unclear on the electron configuration of ions. For example; Mn +4 would seem to be 4s2 3d1, but instead it is 3d3. Ok, I get that an atom is stable at half full, or full, but it is not clear to me why 3d3 is anymore stable than 4s2 3d1.
Could someone help me here?

Thanks

 

[eli64]

I'm not sure if you have come across this yet, but that configuration is due to the crystal field splitting of the d orbitals when transition metals bind with ligands (molecule or ion that binds to a metal ion to form a complex). The 4s and 3d levels are not much different in energy and when a metal ion has ligands bound to it, the 3d levels can become lower than the 4s one due to a gain in stabilization energy. So the 4s electrons move over to the 3d orbitals.

Then all the d orbitals are no longer all the same energy with 3 of them lower and 2 higher or vice versa or other configuration (it depends on the molecular structure) And anytime a chemical species can find itself in a lower energy state, it will do that.

see these for more info
http://en.wikipedia.org/wiki/Crystal_field_theory
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch12/crystal.php

 

[MichaelXY]

Thanks for the response. To be honest I had to look up ligands in my book. It is covered in Chap 24 of my book, I am on chap 6-7 (Electron Configurations). So what you said went way over my head.
BTW the book I am using is Chemistry The central science by Brown lemay Burstein.
Thanks for the help though.

 

[eli64]

Yes, good book see pg 1034-1039. And its a subject covered in maybe 2nd year univ inorganic chemistry. So I didn't think it would make much sense at this point.