Home > Community > Inductive effects of halogens
Upvote

27

Downvote
+ Halides
+ Biochemistry
Posted by
Kaju Deka

Inductive effects of halogens

Albert Donnay  Follow

All your observations are correct.But one thing you seem to be missing is the presence of vacant d orbitals in Chlorine.I am sorry but I couldn't find pictures as such but I am sure you will understand after drawing out the resonance structures.

So when the lone pair on oxygen is delocalized and is at para position,then the d orbital of chlorine can "take up" and stabilize the compund.Flourine can't do the same.

More

Upvote

VOTE

Downvote
Hans Proebsting  Follow
@orthocresol I am a student myself and I recently learned this.But can you tell why d orbitals arent a good explanation?More
Upvote

VOTE

Downvote
Emmanuel Simiyu  Follow
chemistry.stackexchange.com/a/5242/16683More
Upvote

VOTE

Downvote
Jim Short  Follow
But d orbitals arent a good explanation.More
Upvote

VOTE

Downvote
Gary VanRemortel  Follow
This is the picture you want. More
Upvote

VOTE

Downvote
Jeff Lewis  Follow
@Karan Singh If it was at the ortho position then I would have agreed but at such a long distance it doesnt seem very accurate.More
Upvote

VOTE

Downvote
more replies
Bob Clark  Follow

Order of -I in Halogens is −F > −Cl > −Br > −IOrder of +M in Halogens is −F > −Cl > −Br > −I

So whenever halogens are in resonance (as in p-fluorophenol and p-chlorophenol), we take combined effect as:−F < −Cl < −Br < −Iand consider halogens as an overall EWG.

Hence, p-chlorophenol is more acidic than p-fluorophenol.

More

Upvote

VOTE

Downvote
Jason Stone  Follow
This is a wrong answer, your second line contradicts itself. Halogens are considered overall as electron-withdrawing groups. Right. Then the withdrawing effect is inductive effect, so shouldnt the order of -I in halogens be considered, giving F > Cl? Think it over. Also, when you answer, including a source, from a good textbook or online resource, is a great idea.More
Upvote

VOTE

Downvote
David B?ckman  Follow

This is due to the fact that we also consider +M effect . In fluorine it’s 2p orbital that participated in overlapping but in chlorine it’s 3 p orbital. 3p of chlorine does not overlap efficiently with 2p of benzene carbon so +m decreases in chlorine thus acidic nature increases

More

Upvote

VOTE

Downvote