F2 bond

[bajoneswadup]

I swear I read in TBR that F2 is a weak bond b/c it contains a pi bond and no sigma bond. My friend just called me insane. Am I getting this mixed up with something? If I am, can somebody tell me what that weird exception is that I can't think of.

Note: I know abt electon repulsion

---

Members don't see this ad.

 

[chaser0]

No you are correct.
F2 is one of those weird ones

Its on page 11 of the BR orgo 1 book. If you want to show him.

 

[Temperature101]

I swear I read in TBR that F2 is a weak bond b/c it contains a pi bond and no sigma bond. My friend just called me insane. Am I getting this mixed up with something? If I am, can somebody tell me what that weird exception is that I can't think of.

Note: I know abt electon repulsion

This is somewhat a short sigma covalent bond...F has 9 electrons. 1s2, 2s2 and 2p5. So you need to share only one electron with the other F to complete the octet...Therefore, one covalent sigma bond...Why do u think it has a pi bond?

 

[Temperature101]

Wow....Did not know that exception...My bad.

 

[syoung]

Isn't the exception because in molecular orbital hybridization, F must use the p orbitals to bond with each other?
If we look at N and O, when they make their diatomic's, they use both the s and p orbitals to hybridize and make their triple and double bonds respectively. But fluorine can't double bond, BUT still has to bond in the p orbital, so that's why it gets 1 pi bond?

 

[chaser0]

It is because N needs 3 bonds to complete its octet
O needs 2

F only needs 1
All Halogens are single sigma bonded diatomic molecules.
F2 is a funky in that it uses 1P bond istea of a sigma bond.
This is due to The small size of F. It wants to create a sigma bond but there is too much repulsion at the distance it needs to be. So it has to resort to a Pi bond.

 

[Temperature101]

Isn't the exception because in molecular orbital hybridization, F must use the p orbitals to bond with each other?
If we look at N and O, when they make their diatomic's, they use both the s and p orbitals to hybridize and make their triple and double bonds respectively. But fluorine can't double bond, BUT still has to bond in the p orbital, so that's why it gets 1 pi bond?

If it's not an exception, the same thing should happen with all the halogens then....
Edit...It's due to the small size of F2...Got it now.

 

[syoung]

If it's not an exception, the same thing should happen with all the halogens then....

dur, right you are!
it's the damn small size of fluorine. gotcha.