[xshadow]

I dont' understand very well when a distortion (for example z axis elogantion/compression) can occour in an octahedral complex


-I've read that can occour when the six ligand are different...for example [M(Cl)₄O₂]  ^{+/- n} ...the oxygen ligands can cause a compression on the z-axis

- In another example I've seen a complex with  the same 6 ligands  [M(NH3)₆] that can follow an octahedral distartion....but usually when is a d⁸


So can a distortion occour in both cases??
THANKS

[Orcio_87]

Complex with different ligands are obvious, but distortion can occur also with 6 same ligands - V(CO)₆ is an example. Here are reason of the distortion for a complex with 6 same ligands: https://en.wikipedia.org/wiki/Jahn%E2%80%93Teller_effect