The perfect demonstration of the electrophilic substitution that takes place during bromination. The details about how the electrons are transferred between the catalyst, electrophile and benzene ring. My book simply mentions Bromine molecule being polarised by the catalyst without any explanation whatsoever. It wasn't until I watched your video that I clearly understood the mechanism behind it. Thank you so much Mr. Khan.
Epiphany moment: It's an acid catalyst because you end up with what you started with and haven't used any of it up. Not really relevant but I remembered this and had an Eureka! moment...
Yeah for my upcoming chemistry exam we definetely don't need to learn the mechanism this in-depth. A real shame in my opiniom, useful to know how it happens exactly
Dear sir. Thank you for your time. However, please understand that there is a mistake here. When you move the single electron from BR-BR to the FBR3, you may only use a single headed arrow not a double headed arrow, because only one electron is moving, not a pair. Thanks a lot.
Fe: i want electron lets rip off those 2 Br Br1: hey this is my electron! i'm not letting go of it. Br2 bro can i have your electron? that Fe took mine. Br2: no stop pulling my electron you communist. ah stop it alright you can have it i dont want it anyways im just gonna take the electron from benzene bro he got enough of them...thanks benzene benzene:now i have a hydrogen too much anyone want it? br1: me me H: GTFO Fe im taking that electron. hi Br1 how you doing baby? Fe: wait what? fuck me!
@kourosh89 the pi bonds in the benzene ring are just too stable to be easily broken up. when the Br2 goes with the iron bromide, causing one of the bromines to become positive, the molecule is a strong enough electrophile to break the pi bond.
I guess this reaction is highly thermodynamically unfavored, just considering how much more polar is the H-Br bond with respect to the Br-Br bond (in reactions, nature tends to minimize the exposed charge), and the symmetry loss in benzene -> bromobenzene. So it is pretty hard for the first substitution to happen, let alone the other five.
those Br's are a bunch of bullies stealing other peoples electrons on the playground. first they are mobbing the Fe and taking almost all of its elecrons. then they fight eachother, then they rip off that benzene and steal its elecron and then the other bromene steals the hydrogen of the benzene. WATCH OUT it's a Br under your bed its gonna take your stuff when you are sleeping :D :D :D
how is the 4th bromine in febr4- even bonded to it. I mean if the 4th bromine has a nuetral charge now how would it bond to the febr3. Wouldn't it just leave? theres no covalent bonding or ionic so what is happening.
Also in reaction you would make the other reactants in excess in relation to the catalyst, and I guess preferentially the benzene ring in excess to the Br2.
I have a question sir why would bromine want to give away its electron to Fe though it was told in the video that it would not occur always only at a particular condition.but still why would bromine give it to fe.
Hey Aditya! , so you are asking about why bromine gave an electron to Fe , so it can be seen like this , in FeBr3 , Br is very electronegative and sucks electron into it , and makes Fe a little bit positively charged , now there is about 30% chance ( chance probability i am only guessing....) that this FeBr3 molecule will bump into Bromine molecule(Br2) at right times and right energies and when this happens Iron says - hey give me an electron , i am feeling uncomfortable , and bromine gives it off , this is only due to the fact that 3 bromine molecules make Fe much positive and force it to act like a lewis acid or you can say " A FAIRLY STRONG ELECTROPHILE" , hope that helped.....
Halides are massively electronegative. So why is that bromine atom willing to have a positive charge? My guess is that the Lewis-structure approach is a bit off, for this type of reaction, and what we really need is something like molecular orbitals. That is, I'm guessing the bromine isn't really having a positive charge. Instead, the transient species FeBr5 is a lot more stable than it looks (which still is not particularly stable, but it doesn't have to be), because the actual charge distribution you get when you do the QM will turn out to be different than what the Lewis structure shows.
Dan Wylie-Sears Because the iron bromide catalyst causes the right bromine to become 'more electronegative' allowing it to be favoured. The same happens without the catalyst however is much harder to get a reaction. The bonding electron pair is constantly oscillating between Br-Br which allows a partial negative and positive charge to exist. This is enough for it to act as an electrophile.
why does the hydrogen attatched to the 'bromine carbon' got nabbed, instead the hydrogen attatched to the electron deficient carbon atom can also be taken away. PLZ help. The lecture was superb. I wish you were my CHEM. teacher......
Mydoubt pathe Bromine's electronegativity allows for the hydrogen that is also attached to the carbon to become partially positive. This doesn't happen with the other hydrogens (infact it becomes partially negative). This partial positive charge allows for the nucleophile to liberate the H+ and allow the reaction to take place.
that is not benzene tho ? its kekule's structure of benzene which was later proved wrong. benzene has an delocalised highly electron density ring above and bellow the carbons
its been 10 years for this vid and i feel o proud to study with you
The perfect demonstration of the electrophilic substitution that takes place during bromination. The details about how the electrons are transferred between the catalyst, electrophile and benzene ring. My book simply mentions Bromine molecule being polarised by the catalyst without any explanation whatsoever. It wasn't until I watched your video that I clearly understood the mechanism behind it. Thank you so much Mr. Khan.
I absolutely love your videos ! You make everything so easy ! :) Thank you ! Stay blessed
Epiphany moment: It's an acid catalyst because you end up with what you started with and haven't used any of it up. Not really relevant but I remembered this and had an Eureka! moment...
mhan that's a hell of an interesting story...amazing explaination sir! thnz
thank you so much! my teachers never explain why we have FeX3, makes perfect sense now thank you!
Thank you. This video makes my life easier. Very helpful indeed.
Yeah for my upcoming chemistry exam we definetely don't need to learn the mechanism this in-depth. A real shame in my opiniom, useful to know how it happens exactly
"Electrons are fungible." Such an eloquent way to describe such a big source of confusion in arrow pushing in reaction mechanisms.
Dear sir. Thank you for your time. However, please understand that there is a mistake here. When you move the single electron from BR-BR to the FBR3, you may only use a single headed arrow not a double headed arrow, because only one electron is moving, not a pair. Thanks a lot.
I love your Voice sir.
Lovely Teaching.
You always Saved Me in Exams.❤️❤️❤️
you're an Indian.....
Thanks I definitely need a refresher for this reaction.
let me draw the BENZENE RING
so easy.....thanks for this awesome video
Be seing the quality , No one can believeit is 10 years past video....😎😎😎😎😎😎😎😎😎😎😎😎
Fe: i want electron lets rip off those 2 Br
Br1: hey this is my electron! i'm not letting go of it. Br2 bro can i have your electron? that Fe took mine.
Br2: no stop pulling my electron you communist. ah stop it alright you can have it i dont want it anyways im just gonna take the electron from benzene bro he got enough of them...thanks benzene
benzene:now i have a hydrogen too much anyone want it?
br1: me me
H: GTFO Fe im taking that electron. hi Br1 how you doing baby?
Fe: wait what? fuck me!
😂thank you , makes it super fun and easy to remember
yessri. i indeed found that vaguely interesting.
You are a legend !!!!
Cobalt has 2 valence electrons but as it has a metallic bond it really has 15 electrons and 2 that have been delocalised.
@kourosh89 the pi bonds in the benzene ring are just too stable to be easily broken up. when the Br2 goes with the iron bromide, causing one of the bromines to become positive, the molecule is a strong enough electrophile to break the pi bond.
I guess this reaction is highly thermodynamically unfavored, just considering how much more polar is the H-Br bond with respect to the Br-Br bond (in reactions, nature tends to minimize the exposed charge), and the symmetry loss in benzene -> bromobenzene. So it is pretty hard for the first substitution to happen, let alone the other five.
Thank you
those Br's are a bunch of bullies stealing other peoples electrons on the playground. first they are mobbing the Fe and taking almost all of its elecrons. then they fight eachother, then they rip off that benzene and steal its elecron and then the other bromene steals the hydrogen of the benzene.
WATCH OUT it's a Br under your bed its gonna take your stuff when you are sleeping :D :D :D
Haha I love this comment, also helped me remember what happens better thanks
It's a bit confusing seeing the kekule benzene instead of it being a ring. Good video though, helped a lot.
Almost correct. It would be 1,2,3,4,5,6-hexbromoclycohaxane or 1,2,3,4,5,6-polybromoclycohaxane
Chris Ellis nope, the delocalisation stays.. it is HexaBromo Benzene
Thankyou! God bless you! Very helpful :)
Can you please please make a video about Nitration and Sulfonation of Benzene.. Please..
how is the 4th bromine in febr4- even bonded to it. I mean if the 4th bromine has a nuetral charge now how would it bond to the febr3. Wouldn't it just leave? theres no covalent bonding or ionic so what is happening.
4:43
ya bro
bromination
I found that vaguely interesting.
THIS IS SO AWESOME
A decade later, I still completely agree!
Also in reaction you would make the other reactants in excess in relation to the catalyst, and I guess preferentially the benzene ring in excess to the Br2.
Amazing 👍🏻
Thank you so so so so so much Sir. Your videos are really really really really helpful.
I apologize for the inconvenience.
Hey how many valence electrons has Co? (just wondering)
All of my BROmines are always cool
Yeah, I think they just go with the FLuOrine. 😎
Should grab proton from allylic position. not from substatuteing postitiion.
but good video
Sir, what would happen if we use CS2 instead of febr3
I have a question sir why would bromine want to give away its electron to Fe though it was told in the video that it would not occur always only at a particular condition.but still why would bromine give it to fe.
Hey Aditya! , so you are asking about why bromine gave an electron to Fe , so it can be seen like this , in FeBr3 , Br is very electronegative and sucks electron into it , and makes Fe a little bit positively charged , now there is about 30% chance ( chance probability i am only guessing....) that this FeBr3 molecule will bump into Bromine molecule(Br2) at right times and right energies and when this happens Iron says - hey give me an electron , i am feeling uncomfortable , and bromine gives it off , this is only due to the fact that 3 bromine molecules make Fe much positive and force it to act like a lewis acid or you can say " A FAIRLY STRONG ELECTROPHILE" , hope that helped.....
Halides are massively electronegative. So why is that bromine atom willing to have a positive charge?
My guess is that the Lewis-structure approach is a bit off, for this type of reaction, and what we really need is something like molecular orbitals. That is, I'm guessing the bromine isn't really having a positive charge. Instead, the transient species FeBr5 is a lot more stable than it looks (which still is not particularly stable, but it doesn't have to be), because the actual charge distribution you get when you do the QM will turn out to be different than what the Lewis structure shows.
Dan Wylie-Sears Because the iron bromide catalyst causes the right bromine to become 'more electronegative' allowing it to be favoured. The same happens without the catalyst however is much harder to get a reaction. The bonding electron pair is constantly oscillating between Br-Br which allows a partial negative and positive charge to exist. This is enough for it to act as an electrophile.
why does the hydrogen attatched to the 'bromine carbon' got nabbed, instead the hydrogen attatched to the electron deficient carbon atom can also be taken away. PLZ help. The lecture was superb. I wish you were my CHEM. teacher......
Mydoubt pathe Bromine's electronegativity allows for the hydrogen that is also attached to the carbon to become partially positive. This doesn't happen with the other hydrogens (infact it becomes partially negative). This partial positive charge allows for the nucleophile to liberate the H+ and allow the reaction to take place.
what if the benzene ring was attached to another cyclic compound like 1-Cyclopentyl-4-methoxybenzene for instance? where would bromine go?
Sorry if I am making a mistake but isn't FeBr3 ionic? Why is it represented as molecular?
that is not benzene tho ? its kekule's structure of benzene which was later proved wrong. benzene has an delocalised highly electron density ring above and bellow the carbons
what is the application/ programe used in illustration ?
thanks
jst wondering is C=C in bezene allowed ?? i mean last time i checked no in A'level syllabus as its a wrong concept.. any help?
idk why everyone thumbs down this comment. Sal said i hope you found this vaguely interesting at the end of the video. It's a joke
I don't get why the negative Fe didn't take the final hydrogen and force Br off instead of Br taking it to form an acid.
I don.t understand any thing🙂
You made the simple very complex🙂
Amazing
THIS IRON BROMIDE IS ALSO CALLED FERRIC BROMIDE....
world class
is a lewis acid the same as a halogen carrier
Why wouldn't this mechanism keep going until you end up with 1,2,3,4,5,6-hexabromobenzene?
You give me that lab process in small amount of make p-bromobenzin from bromobenzene
Why have you drawn benzene with double bonds rather than a circle
You made this simple reaction really difficult.
Darsheed Mustafa Only because he used a catalyst.
Darsheed Mustafa that's exactly how this reaction go. Nothing in orgo is simple as u think
Great!
Thanks !!!
ابلص😂💚
Isn't a benzene ring C6H5?
Clear as mud.
@mrmagnetoman88 i think so...
No, Benzene is C6H6 or CHCHCHCHCHCH
great im more confused now.
I think it's so difficult and pharmacy so difficult too🙃
paint
Why? 💔
@WA5CVI loll did u watched the whole video...
#51
like ❤