H2O + NiCl2 -> why is it octahedral?

[Michelle Li 2B]

Hi! In class, when Dr. Lavelle was discussing how transition metal cations in solution form complexes with H2O, he drew an octahedral structure of NiCl2 where Ni was the central atom with two Chlorines bonded (one on top and one on the bottom) with four H2O molecules surrounding the Ni atom. How do we know that this structure is octahedral and why does it have to be octahedral? Thank you!

[Alexandra Gill]

Since there were six regions of electron density (the six bonds) surrounding the Ni central atom, it is octahedral since molecules with that shape have 6 regions of electron density.

[Chloe Fuson]

Has kind of already been said, but just to reiterate, since the central atom (Ni) has six ligands bonded to it, it is an octahedral complex. This is just the generic name for a complex with 6 ligands.

[sophiavmr]

A complex with 6 ligands will always form an octahedral geometry.