Got another practice question but I'm really stumped on this one:

If the [ZnCl4]^2- ion is diamagnetic what must its structure be and why - octahedral, tetrahedral or square planar?

I know that diamagnetic means that all its electrons are paired and that makes it low spin (I believe) but how do I predict its shape? I think maybe its tetrahedral but I am totally guessing. (This is another practice question to prep us for Organic next semester, not for any points, so I want to understand the thinking behind it). Thank you!

5 answers

Here is a site with a lot of reading. If I read it right, four coordinate complex have tetrahedral shapes except for d8 configurations and those can be spare planar OR tetrahedral. Cl is a log range splitting anion and I think ZnCl4^2- is tetrahedral.
http://wwwchem.uwimona.edu.jm:1104/courses/CFT.html
Thank you again, I really hope you are going to be around this summer for Organic :)
You won't be when summer gets here for you will find I am NOT an organic chemist. I can help with VERY VERY basic organic but after the first two/three questions I run out of steam.
That's okay, I'm sure you're better at it than I am.

And you are good at leading me in the right direction; I appreciate that. It'll all work out.
P.S. I have heard that you are either a Gen Chemist or an Organic Chemist. (I am hoping to heck I am an organic chemist! But, I did well in Gen Chem, thanks in part to you.)