Sapling #3 pt. 2

[Tae Pasawat 2A]

Can someone please explain why a seesaw shape is not possible for complexes with a coordination number as 4? Is it because seesaw has 5 e- density regions (and 4 bonds) and it makes it unstable?

[Charlotte Adams 1A]

If a complex has a coordination number of four, a seesaw shape would not be the most stable structure because the atoms are not as far from each other as possible, like in a tetrahedral or square planar shape.

[Can Yilgor 2D]

I also thought about the same thing. I guess it's just uncommon for coordination compounds to have a see-saw arrangement.

[SashaAnand2J]

I believe coordination compounds typically have 2, 4, or 6 electron dense regions, and VSEPR shapes that align with these are the most stable for those compounds (specifically when the shape generates some form of symmetry). Seesaw is a very asymmetrical shape, so I'm assuming that is why it is less stable.

[Katherine_Douglas_1F]

I was also a little confused on this, but I think it is because coordination compounds tend to be more complex and come in pairs to make the compound more stable. Since a seesaw shape has 4 bound atoms and one lone pair, the structure would not be as stable and, as such, is very rare. Since the question was asking for the most common formations, seesaw would not be included.

[Savannah Torella 1L]

I was also confused with this at first. Since it was only asking for the common shapes, a seesaw would not be included. Since the seesaw has 5 e- density regions, it is not as stable as ones that have 4 or 6, making it less common.