Nucleophilic Substitution : SN1 and SN2

[footballfreak1904]

don't know why there are some dislikes.

tomorrow, i'll have to write an exam on this topic and this video is a perfect quick overview on this terrifying mechanism :D

[CheckerVomNecker112]

Nice video, although I'm German I understood more than in the German texts.

[Intellectualidealist]

It is definitely CH3 because it is a CH connected to C (or any atom for that matter). The C from the CH is alreafy bonded to 2 things (the H in CH as well as the central/main C). C can have only 4 bonds, so 4-2=2. the CH is also bonded to another 2 H's. Therefore, CH+ two H's= CH3.

[MonaRocks09]

AUDREY YOU ROCK

[sKaYj2]

Great vid, really like it, just wanna say that people also have to know that the time taken for sn1 and sn2 are important and determined by the RDS (Rate Determining Step), which is the first one (and in sn2's case the only one), you did mention that Sn2 is faster but you didn't really kinda specifiy, I dno just felt like throwing that out there :3

[Xshado2]

This concept it easy to understand, it would be nice if you made a video explaining how hybridization works and how the Pi and Sigma bonds form in single, double and triple bonds... (PS is this a highschool topic? cuz im taking it in highschool)

[sandeep88214]

Really good

[junior1984able]

what the hell just happpend

[tehhhhhd]

Oh lawd, is that sum massive attack - teardrops?!

[spacemonkie89]

Wow. Ive been staring at my book for hrs now and that 2 minute video made me completely understand Sn1 and Sn2 reactions more than my book and professor did! Thanks for the video!

[MsFairy66]

nice

[PewPewTiger]

I love Audrey NAIL0r :D

[X1XhieiX5X]

CH = CH3?

[TurkmenKiZ89]

@X1XhieiX5X No, it's CH2=CH2

[X1XhieiX5X]

@TurkmenKiZ89

I was talking about the CH s at 0:14. Lol, but I can see how what I said could be misinterpreted. :P

[TurkmenKiZ89]

@X1XhieiX5X ah yes you are right :) It must be CH3 ! this video is not helpful

[PennyForTheOldGuy]

Whoever said they didn't like the music and old-time film effect, get a life. It presented old information in a new format, and in my exam, I will hear "The Entertainer" and remember this video. ( Much more than I would remember a video with scarcely any music and a poor powerpoint animation.)

[TheDEMAN92]

Thanks for this simple explanation, you saved me from hours of study

[sugarfacex]

gay 

[atifrocks]

very helpful thanks!

[flamingthunder3]

this isn't bad. its a basic demonstration of the difference between and mechanisms of SN1 and SN2 rxns. its hard NOT to understand it. although i can understand why someone who is lost would criticize it, with the film-strip motion and all.. Good nonetheless.

(btw, responding so defensively to everyone who criticizes the video makes it seem like you DO care, more than you should. Just ignore it, its only the internet/youtube. lol)

[Sasha7amad]

GREAT JOB!!! 

[UOTLTube]

LOL the Nucleophile "attacks from the back" if you know what i mean

[luizidd]

I`ll see it..

[PR00H]

Also i love how people type they couldnt care less, proving they could in fact care much less.

[PR00H]

"I'm sorry, but the film grain, film-strip motion and the music just make this too schizophrenic to be as useful as it should be. "

agreed

[saqikhan1000]

its not enough bt great attempt !! cool man!!!

[TzarBomb]

interessante, simples e direto, muito bom.

(se meu professor fosse assim as aulas seriam bem melhores...)

[varoun316]

very helpful and saved alot of time

[Dxylose237]

Haha! This is awesome :)

[MariusSemeonOrtiz]

thanks so much, favorited this and 5* :) One thing though, shouldn't the departing group in SN2 be Br- not Br? Br suggests homolytic fission and that doesn't make sense in this case

[micb2792]

This video is so straightforward. Substitution Nucleophilic reactions didn't really make much sense to me (especially drawing transition states) until I saw this. Thank you!

[BelaStas]

i think this is very helpful. Made my pre-lab so much easier.

[xjoncamposx]

lmao at you guys pissing her off.

[KageKitsune343]

Very usefull, thanks=)

[Phronesis7]

Wow! Thanks so much for this. Best summary I've seen so far!

[babbyluvin]

just ignore that bafoon ! i totally loved it.

it was snappy and expained all i just needed to understand the whole thiing.. thank you and God blees =)

[ajkcornergas]

This thing is awesome. BB0YMatty I don't know where you get your educational information but this is the best I have found so far, good job evolutionfaudrey

[Kogoruhn]

Thanksss

[BB0YMatty]

well you missed alot of information on secondary carbons and how solvants will affect the reaction.

[BB0YMatty]

sorry but this sucks, moving up and down, nothing better to hurt someones hurt trying to understand 1/5

[caifuge]

lol this is too fun

[peepslayer101]

I'm sorry, but the film grain, film-strip motion and the music just make this too schizophrenic to be as useful as it should be.

[kkyy23]

whats the song title

[erlover3]

The Entertainer

[hoyhoyhoyhoyhoy]

For your Sn1 rxn, Br is the wrong type of nucleophile. Remember that Sn1 rxns can only occur in the presence of a substrate that is a weak nucleophile/weak base. Br is a strong nucleophile, and therefore would participate in an Sn2 rxn instead of Sn1. For your Sn1 rxn, if you switched H20 as your weak nucleophile for Br, and Br as your leaving group instead of your nucleophile, then your Sn1 rxn would be correct. Good video though.

[hoyhoyhoyhoyhoy]

scratch 'substrate', i meant reagent

[hoyhoyhoyhoyhoy]

one more thing, your substituents in the sn1 rxn are suppose to be methyl groups (CH3) in place of each CH group.

[evolutionofaudrey]

Thanks for your comments. My reply remains the same: the information was taken directly from the textbook, and while I apologize for its inconsistencies, they rest with the authors of the sixth edition of "Fundamentals of Organic Chemistry". I think it's fabulous that you have this knowledge and are able to share it (so nicely and wisely) with me and my viewers, and I hope they read your comments to clarify the video - but I'm afraid I can't accept corrections. I encourage you to make your own!

[biohax]

i see what you're saying...it needs enough energy for displacement so a weaker nucleophile would be unable to displace anything stronger

[alarmstr0ng]

does the video have different speeds? my gf would love for a present if so

[punkgalician]

Yeah nucleophilic substitutions make the world a better place to live... ^^

[ieatsgoats]

I threw up watching this. Do not watch if you get motion sick!

[Director1221]

Thank you very much.

[vdj0077]

damn it look so easy... i wish i will not fail the test

[leeth419]

shaky video made me turn away

[YgdrasilChris]

how did you make it? are you using any specail software?

[Sheepshead18]

It should be noted that in the video, the Sn2 reaction is shown taking place on a secondary carbon, and although this can happen, it occurs much more frequently with a primary or methyl carbon... but im guessing this was just done to show the inversion of the stereochemistry woot

[sp826]

i love you!!!!!

[krealle]

Thank you thank you thank you. Just saved my ass in my Organic Chemistry class :)

[pikaperson01]

Great video. Explained it very well.

[vash01000100]

nice vid

[paopaomanalansan]

That was informative, thank you!

[LeeDiddy990]

wow I understood that in 20 seconds instead of staring at my textbook for hours. I wish my professor would actually do so something like this instead of reading from the book. Thanks for the explanation its so clear and vivid.

[F0TW]

Thank you very very much.

[aaltijanie]

lifesaver

[badbooboo33]

gr8 vid! explains it well!

[SoCuteNY]

NICE!

[Rukida]

omg why did i not find this sexy beast earlier?

[shimshutian]

wonderfull....

[revolver7725]

great video, really

[xomzcutenessxo]

so cute, thank you.

[gykmeister]

i do not know who you are but i now love you!!! You have made me a very happy man to understand that, damn stupid lectures and not good explanations!

[afgsabrina07]

what is the inversion of steriochemistry? why does it do that?

[afgsabrina07]

omgg thank you so much....

[freeesia]

this was really helpful! thanks

the music makes me happy too lol

[HardcoreChemist88]

Awesome...

By the way, this video is too shaky... @_@

[fh1mahfanzai]

so Br is the leaving group yeah?

[cachu2002]

thank you very much!!!!!

[hopsi222]

but the br in the end is negative right?

[jonathanbouchard]

If all the information on internet was this good and this fun to learn... Thanks Audrey!!

[cAizella]

thank youu this helps a lot!

m having my organic chem test 2moro

hahahaha XP

[hawkssens]

Oh, no! I've got a test on this tomorrow and you lost me on :29.

Organic chemistry is impossible to understand!

Thank you for this video!

[Evilbible]

thank you, this really helped

from an A-level student

[teddyterrorist]

lol

[sdegregorio]

Brilliant. Thanks :D

[kellkat07]

You rock. I've been on computer forever trying to understand SN1 & SN2. Thank you!

[stv7410]

That comment a few lines down is actually correct....the picture at 0:15 is wrong b/c those carbons connected to the central carbon must each be bound to 3 hydrogens...it looks like you may have missed the subscript "3"

[fh1mahfanzai]

lol yea, but u know wat these are methane :)

[mactipoftheweek]

I think i might use this to help teach an organic chem student of mine this summer.

Very cool.

--Chris

[Shrubbs]

Oooh, very helpful

I'm taking orgo I & II over the summer (crash course) and this mis pretty straight foward

[TheNamelessMaggot14]

thanks, this is great help

[sexyboy78630]

carbon should be bonded to four atoms unless its a carbocation. that means the first picture shown is wrong

[evolutionofaudrey]

Thanks for your comment. I like that you went out of your way to bring this to my attention. However, if you read the discussion thread and credits of the movie, you'll see that a number of very educated people have agreed that the content is correct. The information comes from a reputable college textbook, which is credited. Finally, the first picture shows a carbon atom bonded to four atoms - when it loses an atom later, you see a positive charge. Thanks for your input, though!

[sexyboy78630]

what is the reference of the college textbook so i can double check? thank you

[mattpbent]

Hi Audry [Assuming you were trying to draw 2-methyl propan-2-ol]. He is not talking about the central carbon atom -which is correct -he means the three "methyl" groups(CH3 not CH) coming off the central carbon -they should each have three hydrogens attached -stv7140 is correct as is sexyboy78630. Check it up !

[goodmenace]

Thanks so much! Very helpful.

[LuvOurEarth]

aweseome thank you so much. it helped a lot in understanding the main difference between those two rxns.

Hurray!! lol :D

[stinkyshoe113]

Cute video. I like it.

[Jen7waters]

hurray!

[si1entmage]

hmm there sumthing im not sure of... i tot OH- is a better nucleophile? then how come the cl can go in and take OH- place? even if it do so, wont the H2O become H+ and OH- again and the OH- sub in again?

[vyasan]

or she forgot to mention that the OH has been protonated to make it stable.

[fullback118]

Thanks, helpful video

[Nogitsune07]

It seems so much simpler when you watch the reaction on video than read it off a page. Thanks for the invaluable help!

[Forlo12345]

very helpful, thank you so much.

[Pigglies]

That's really cool! I was just sitting here studying this and thought I'd search for a video on it. Yours really helps (and of course, I'd always rather be watching videos than reading). Thanks!

[Westsidegangzter]

What the teacher tried to explain to us in 2 hours, you just did in 2 min ;) Thanks, now I'll will get an A fo' so'

[drunkchemist]

At 1:55, the way you have it drawn it's (S)-Butan-2-ol because the smallest group is coming out (H), the methyl group and the hydrogen should have reversed their stereochemistry. Otherwise, nice summary

[mattpbent]

Think it appears to be (R )! -If you apply the CIP system . Rotate the molecule 180 degrees and now the hydrogen faces away ,you should get a clockwise rotation ?.

[drunkchemist]

To be perfectly honest, I am not familiar w/the CIP system, I was never taught it; however the way it's draw it is (S), because the smallest group (H) is coming out, it should be reversed with the methyl group, than it would be (R)

[mattpbent]

Hi ! Fairly sure its R -- just because it has the hydrogen coming out does not make it automatically (S) -- if that is what you are saying?? . To find the correct rotation you must always have the H ( or the smallest weight) facing away from you , then see which way the numbers go. The Cahn Ingold Prelog system is fairly universal. What system do you use?

Regards MattP

[befz88]

i also agree its R. Have the hydrogen facing into the plane of the page and the 3 substituents facing you, then have it so the substituent with the largest atomic weight is at the top and go to the next largest atomic weight substituent, if you go left first its S, if you go right first its R.

[mattpbent]

yep that explains it fair;y well !

[shaunmikex]

amazing. I'm taking this in summer (cram sessions); this was definately an amazing summary

[jimad12]

can you post esterification (methyl benzoate)? thanks

[sled0815]

great help, thanks!

[zentokukai]

It's like a tragic love story - the bromine leaves at the end and taked the electrons with it =(

[Bacillusmegaterium]

hehe I felt so perky watching that.

[mshehab]

ugggh ohh man i just had an exam on this

[LongbowHawk]

Brings back fond yet painful memories of o-chem... so many reaction mechanisms to think about :P SN-2 aka the "backside attack" is still my favorite though

[Garbage101]

dun forget e1, e2 and e1cb reactions...also aromatic nucleophyllic substitution rxn's, sigmatropic, electrocyclic, pericyclic, etc (and tons more .... inst chemistry grand!)

[imightbewrong06]

nice man, i have organic final tomorrow as well...and I'm gunna fuckin' "back side attack" it!

[onetoughguy920]

OH is a bad leaving group cuz its a good nucleophile...but when protonized! converts the hydroxide into water...and water is a horrible nucleophile and thus is a great leaving group...and is kick off because bromine is a better nucleophile than water because of its stability as an anion and it ability to donate it electron pair to the carbocation :) hope tht helps

[sjoh1679]

Idiot! Make sure you know what you are talking about before informing others. By your 'logic' iodide would be a poor nucleophile since it is a great leaving group, which is wrong. Ever heard of nucleophilic catalysis!!!!

[niuchemist]

It's a common undergrad mistake. I even used to make it. The problem is that nucleophilicity is a kinetic property and basicity is thermodynamic, so the argument doesn't hold.

P.S. Water is a decent nucleophile - ask any biochemist.

[looplooploop]

Hey I thought OH was a bad leaving group!

[lemonheadd]

lmao thank you. i have an organic chem final tomorrow.

[mmacante]

very helpful~ thanks!