coordination number

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Heather Szeszulski 1I
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coordination number

Postby Heather Szeszulski 1I » Sat Dec 05, 2020 12:52 pm

Can someone explain how coordination numbers work and how to fin them from a coordination compound. For example what would be Ba[FeBr4]2 coordination number be and [NiCN4]^2-

IsaacLaw1E
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Re: coordination number

Postby IsaacLaw1E » Sat Dec 05, 2020 1:21 pm

Coordination numbers are the number of bonds the central metal ion forms with its ligands. For Ba[FeBr4]2, the coordination number is 4 because the Fe is bonded to 4 ligands, which are the 4 Br. For [Ni(CN)4]^2-, its 4 because Ni is bonded to 4 CN.

Rose_Malki_3G
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Re: coordination number

Postby Rose_Malki_3G » Sat Dec 05, 2020 2:06 pm

Coordination number refers to the number of donor atoms from the ligands that are bonded to the central atom. To find this, determine what the ligands' types (mono dentate, bidentate, etc.) and based on this, count the number of atoms that are bonded to the centra atom. In [FeBr4]2 the coordination number is 4 since there are 4 donor atoms and in [NiCN4]^2- the coordination number is 4 because there are 4 donor atoms.

Emma Ide 2E
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Re: coordination number

Postby Emma Ide 2E » Sat Dec 05, 2020 2:11 pm

In both of these cases the ligands are monodentate, meaning they only give one donor atom to the central atom, so the number of ligands, which is 4 for both of these, indicates the coordination number. However, if the ligands were bidentate, then they would give 2 donor atoms and the coordination number would have to be multiplied by 2, and so on depending on the denticity of the ligand.

lwon Dis2I
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Re: coordination number

Postby lwon Dis2I » Sat Dec 05, 2020 2:42 pm

Can someone explain more in detail of what bidentate means in a coordination compound and how it is different from a monodentate?

Eric Cruz 2G
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Re: coordination number

Postby Eric Cruz 2G » Sat Dec 05, 2020 2:48 pm

To find the coordination number of the transition metal, you focus on the atoms that bond to the central atom (the TM). Therefore, you only focus on the molecules within the bracket. Therefore for both of them, the coordination number would be 4.

RitaThomas_3G
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Re: coordination number

Postby RitaThomas_3G » Sat Dec 05, 2020 11:45 pm

One other thing to keep in mind when calculating the coordination number is that you don't need to account for the molecules outside of the brackets, because they are out of the coordination sphere.

Kelly Singh
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Re: coordination number

Postby Kelly Singh » Sat Dec 05, 2020 11:48 pm

lwong Dis1L wrote:Can someone explain more in detail of what bidentate means in a coordination compound and how it is different from a monodentate?


Bidentate ligands are able to attach/bond to the transition metal twice. (Tridentate= three times, polydentate= multiple bonds)

Kelly Singh
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Re: coordination number

Postby Kelly Singh » Sat Dec 05, 2020 11:49 pm

Kelly Singh wrote:
lwong Dis1L wrote:Can someone explain more in detail of what bidentate means in a coordination compound and how it is different from a monodentate?


Bidentate ligands are able to attach/bond to the transition metal twice. (Tridentate= three times, polydentate= multiple bonds)


Sorry, forgot to add this. This means that for every one of these ligands, the coordination number would increase by two,

Jasmine Ho 3I
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Re: coordination number

Postby Jasmine Ho 3I » Sat Dec 05, 2020 11:50 pm

You can get the coordination number by looking at how many atoms/compunds are inside the brackets (aside from the transition metal), because those are directly bonded to the transition metal.

Jaden Joodi 3J
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Re: coordination number

Postby Jaden Joodi 3J » Sun Dec 06, 2020 2:16 am

Coordination number is simply the number of the bonds connected to the transition metal cation.

Violet Kwan 3H
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Re: coordination number

Postby Violet Kwan 3H » Sun Dec 06, 2020 3:45 am

The coordination number is the number of bonds made with the transition metal. Some ligands may have more than one bonding sites with the transition metal, such as bidentate and tridentate ligands. A bidentate would count as 2 and a tridentate would count as 3. To get the coordination number, you would add up the total number of bonded atoms.

Chenning Yang Dis3l
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Re: coordination number

Postby Chenning Yang Dis3l » Sun Dec 06, 2020 11:20 am

THank you for the info I was confused!

Leyla Anwar 3B
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Re: coordination number

Postby Leyla Anwar 3B » Sun Dec 06, 2020 11:38 am

Kelly Singh wrote:
Kelly Singh wrote:
lwong Dis1L wrote:Can someone explain more in detail of what bidentate means in a coordination compound and how it is different from a monodentate?


Bidentate ligands are able to attach/bond to the transition metal twice. (Tridentate= three times, polydentate= multiple bonds)


Sorry, forgot to add this. This means that for every one of these ligands, the coordination number would increase by two,

What do you mean by increase by two? If the ligand is bidentate and it connects to the TM two times does that mean that those 2 bonds count as 2 for the coordination number?


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