Achieve Week 9 #5

[405513470]

The question is: For each metal complex, give the coordination number for the metal species.
[M(NH3)3F3],[Cu(NH3)4]F2 , [Co(en)2(CO)2]Br .
I do not know to to start when approaching this questions. Especially, determining whether it is a monodentate or polydentate? I know drawing them would be helpful, but I am not even sure how to start that either.

[Nika Kononov 3E]

The coordination number refers to the number of ligands attached to a metal. To find the coordination number just count how many bonds the metal makes in the coordination sphere.

[almaortega]

Start by looking inside the brackets only! From there, find the metal and then count how many molecules/atoms are attached to it. F5 would obviously be five, (CO) would count as 1, (CO)2 would count as 2, and so on.
When we see the abbreviation (en)2, we have to memorize that each en forms two bonds with the metal at hand, so (en)2 is technically worth 4 ligands and then add the two COs.
I hope this helps!

[Leah Wildmann 1F]

To find the coordination number, look at the number of atoms other than the metal atom within the brackets. This will give you the number of atoms that are bonded to the central atom.

[Eric Sun 2G]

In order to find the coordination number, you should look at the number of molecules/atoms other than the metal atom within the brackets shown. These molecules/atoms are ligands and each ligand is one bond to the central metal atom.

[WendyN_L2]

I think it would take some practice and remembering to recognize whether a ligand is mono dentate or polydentate. Like the other comments first count the ligands in the brackets. But then I would draw out the ligands if you are unsure if it a mono dentate or not. If it is a mono dentate then it only has one atom that donates its lone pair to the metal cation. But for others like en, drawing the shape you can see that two NH2 can attach to one metal cation so it is a bidentate. Hopefully this helps

[705573518]

To find the coordination number, look at the number of atoms other than the metal atom within the brackets. This will give you the number of atoms that are bonded to the central atom.

Do we always ignore what is outside the brackets?

[Kayla Ziebell 1H]

I start by looking in the brackets and basically seeing how many ligands are bonded around the central atom!

[Kayla Ziebell 1H]

I am confused on the last question on #5. How do we go about determining the coordination number for Cd(en)Br2? What is the (en)? Would it be 3?

[Ally Mosher]

For the first one,
Since there are 3 NH3's and 3 F, the coordination number would be 6 because 3+3=6.

For the second one,
There are 4 NH3's so the coordination number would be 4.

For the third one,
en already counts as 2 bonds, and then there are two of them so that is 4. Then there are two additional COS so in total it would be 6

For coordination numbers, only look WITHIN the brackets.

[carrie_karchmer_3D]

Coordination number is the number of donor atoms that are bonded to the metal. So to find the coordination number, we look in the brackets and count how many bonds the metal has. For example, when looking at [M(NH3)3F3], M is bonded to 3 NH3's and 3 F's so the coordination is 6 because it is bonded to 6 donor atoms.