Is the Hybridisation of Manganese in MnO4- Really sp3?

In summary, the hybridisation of manganese in MnO4- is sp3, despite the initial assumption that it should be d2sp due to the formation of 4 sigma bonds and 3 pi bonds. This is because when describing bonding in MnO4- using Valence Bond theory, one must consider resonance between multiple structures, making it difficult to accurately determine the hybridisation. Promoting d electrons to p orbitals and forming sp3 hybrids is one possible approximation, but it is still largely speculative and there is limited research available on the topic. This type of description for transition metal complexes is considered outdated.
  • #1
jd12345
256
2
What is the hybridisation of manganese in MnO4-
Configuration of manganese in 3d5 4s2 right? The paired electrons in 4s become unpaired - electron frm it jumps into the 4p orbital
So now configuration looks like this - 3d5 4s1 4p1
Now manganese forms 4 sigma bonds and 3 pibonds so the hybridisation should be d2sp and the three d-orbitals form pi bonds
But apparently this is not the case - hybridisation is sp3
I don't understand how - it doesn't even have 3 unpaired electrons in p-orbital
Do the electrons from d-orbital jump to the p-orbital?? But why should they?
 
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  • #2
Why shouldn't they jump to the p orbitals. All d, s and p orbitals are nearly degenerate energetically and the electrons distribute so as to minimize energy. You also did take it as granted that the s electron may jump to a p orbital.
The problem is that when you want to describe bonding in MnO4- by Valence Bond theory you do have to consider resonance between dosens of structures, not only one. Many of them being ionic ones with electrons jumping from Mn to O or the other way round.
In this situation, it is hardly useful any more to use hybridized orbitals.
Promoting d electrons to the p orbitals and forming then sp3 hybrids is maybe a possible first approximation. Then you get at least the sigma bonds to the O atoms and you can use the d orbitals for pi bonding.
 
  • #3
Yeah - but can't the d-orbital electrons form the sigma bond
Why do they jump to the p-orbital(increase their energy) and then bond.
They could have stayed in the d-orbital and 2 electrons could have formed sigma bond and other 3 pi bond
 
  • #4
You can also use sd3 orbitals or something in between sp3 and sd3. However, this is all quite speculative. However I would like to see a calculation from the last 30 years at least for confirmation and there is very little available. I would consider this kind of description of transition metal complexes as quite outdated.
 
  • #5
@ DrDu
Sorry i didnt understand - what is outdated?
 

FAQ: Is the Hybridisation of Manganese in MnO4- Really sp3?

What is the electronic configuration of MnO4-?

The electronic configuration of MnO4- is [Ar]3d5. This means that it has 5 unpaired electrons in its d orbital.

What is the hybridization of Mn in MnO4-?

The hybridization of Mn in MnO4- is sp3. This means that the 4 orbitals of Mn (3d, 4s, and 4p) are combined to form 4 new hybrid orbitals.

What is the geometry of MnO4-?

The geometry of MnO4- is tetrahedral. This is because the 4 hybrid orbitals of Mn are arranged as far apart from each other as possible.

What is the oxidation state of Mn in MnO4-?

The oxidation state of Mn in MnO4- is +7. This means that Mn has lost 7 electrons and has a formal charge of +7 in this compound.

What is the magnetic moment of MnO4-?

The magnetic moment of MnO4- is 5. This is because Mn has 5 unpaired electrons, which contribute to its overall magnetic moment.

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