D2sp3 and sp3d2 Configurations of [Cr(NH3)6]3+ Ligand Complex

[AdityaDev]

[Cr(NH₃)₆]³⁺ has Cr³⁺ ion and the ligand is weak field.
Hence the configuration of Cr ion is 3d³,4s⁰
My doubt is,will the ligands donate electrons starting from 3d to form d2sp3 or will it start from 4s and use 4p and 4d to form sp3d2?
I know the 3 electrons of chromium are still unpaired but that d orbital can accommodate 2 pairs of electrons.

 

[Suraj M]

opening up a new 4d for hybridization, is energy consuming, and non stabilizing, isn't it?

 

[AdityaDev]

So its d²sp³ then. But you will have the e_g orbitals filled with electrons from ligands and the t_2g partly filled by the metal's electrons.

 

[Raghav Gupta]

So its d²sp³ then. But you will have the e_g orbitals filled with electrons from ligands and the t_2g partly filled by the metal's electrons.

Yes, it's d²sp³. Yes t₂g will remain partly filled and that implies it would be paramagnetic. Applying some of the concepts of valence bond theory in CFT could be useful.

 

[ycheff]

d²sp³

https://books.google.ru/books?id=7e...MQ6AEwAA#v=onepage&q=d2sp3 Cr[NH3]3+&f=false