Electronic Configuration of Fe+

[AGNuke]

Previously I had been asked the configuration for Fe⁺ as an ordinary question from Periodic Table. I know Fe²⁺ and Fe³⁺ but I have no idea for Fe⁺


I know the configuration of Fe : [Ar]4s²3d⁶

So I accordingly wrote Fe+ as [Ar]4s¹3d⁶

But they say that Fe+ is [Ar]4s⁰3d⁷


I just want to confirm that is this electronic configuration correct?

 

[baldywaldy]

Previously I had been asked the configuration for Fe⁺ as an ordinary question from Periodic Table. I know Fe²⁺ and Fe³⁺ but I have no idea for Fe⁺


I know the configuration of Fe : [Ar]4s²3d⁶

So I accordingly wrote Fe+ as [Ar]4s¹3d⁶

But they say that Fe+ is [Ar]4s⁰3d⁷


I just want to confirm that is this electronic configuration correct?

Yes what they say is correct that's because in a chemical environment the d orbital is lower in energy than the s so is filled before the s orbital( I'm not sure if you would have been taught this yet, i got taught it first year undergrad).

 

[Borek]

Yes what they say is correct that's because in a chemical environment the d orbital is lower in energy than the s so is filled before the s orbital( I'm not sure if you would have been taught this yet, i got taught it first year undergrad).

It doesn't want to be that easy. Blindly using this rule you will get d⁸s⁰ instead of d⁶s² for the ground state of Fe(0), so it is obviously wrong in general.

Unfortunately I don't know answer to the original question, other then "because that's the way it is" (assuming that's the way it is). When it comes to configurations there are rules of thumb that work in most cases, and there are exact calculations/measurements that sometimes falsify the rules. Once you know rule of thumb fails for a particular case you can make any kind of handwawy argument like "in this case low spin/high spin configuration is energetically favored", but IMHO it doesn't give you any more reliable tool to predict the configurations in other cases.

 

[baldywaldy]

It doesn't want to be that easy. Blindly using this rule you will get d⁸s⁰ instead of d⁶s² for the ground state of Fe(0), so it is obviously wrong in general.

Unfortunately I don't know answer to the original question, other then "because that's the way it is" (assuming that's the way it is). When it comes to configurations there are rules of thumb that work in most cases, and there are exact calculations/measurements that sometimes falsify the rules. Once you know rule of thumb fails for a particular case you can make any kind of handwawy argument like "in this case low spin/high spin configuration is energetically favored", but IMHO it doesn't give you any more reliable tool to predict the configurations in other cases.

I meant for ions , for isolated species(with no formal charge) then it does obey the normal rule

 

[AGNuke]

OK... This is the tricky one, but solved!