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i am from india and me and my friends,we are preparing for the hardest exam conducting here and i have literally recommended my whole class so they can improve their organic too.......well 2020 going good so far
Its unbelievable how talented you are at teaching. I've been subscribed for about a year now. From general chemistry, to Bio II to cell bio, and now organic, its outrageous how clear and concise you are. Wish you the best success
You are with no doubt one of the best guides for organic chemistry. Thank you so much for your hard work, I hope more videos will comes on the subject.
I've been studying for my ochem exam for 4 days now and was still so confused and felt like there was no way I could get this information down, but then someone suggested your videos and everything is so much clearer now! Thank you!
it is not always the case that if SN2 occurs on the chiral center it will necessarily invert the steriochemistry there. Because if the incoming nucleophile has a different Cahn-Ingold-Prelog priority from the leaving group.
For once I did not have my headphones in while watching your video and my partner hears your intro and realizes why I've been yelling "HE KNOWS ALOT ABOUT THE SCIENCE STUFF. IT'S PROFESSOR DAVE EXPLAINS!" for the past few days (at 2x speed of course).
Im from the netherlands and I have a (dutch) OCHEM exam tomorrow (also with redox, addition- and condensationpolymerisation) but this video really made it a lot clearer even though its not in my native language! Thanks!
I swear this was the best thing ever. I was testing video after video but None of them was explaining wat everything means thy just went straight to an example
Mr. Dave Sir. Nice way of clearly putting such complex stuff in a micro capsule. Am subscribing today. From ALUVA, Kerala, S. India. Am a Tutor Dear Sir
Amazing video on explaining SN2 reaction! Just a question, at 2:27, surely you must mean the oxygen atom is the electron-rich atom? Not oxygen-rich atom? Keep up the great work Professor Dave :D
Loved the video, but I have 1 question... At 5:33, you said that an inversion would happen at a chiral center, but wouldn't the molecule you are referring to be achiral? It is attached to 3 identical hydrogens.
Awesome video. One question; you say that "the lowest unoccupied molecular orbital is 180 degrees from this carbon chloride bond". How are there any unoccupied orbitals? The carbon has four bonds already, and therefore a full valence shell, sp3 hybridized. So aren't all of the orbitals filled?
So when a nucleophile attacks an electrophile it has to put that electron density somewhere, and it can't put it in any of the ones that are full of electrons, so it goes to the orbital with the lowest possible energy that doesn't have any electrons in it yet. All chemical reactions are HOMO-LUMO interactions in that way! Check out my tutorials on molecular orbitals for more information, preferably the newer one.
Hi there! First off, your videos are amazing and so helpful. Thank you so much for helping students like me understand difficult concepts! Secondly, you mentioned that an inversion happens at a stereocenter but the compound drawn doesn't have a stereocenter. Just wondering why it had an inversion? Thank you!
Really well explained! Very thankful to all the RUclips educators like yourself :) One question I have regarding this: what property of the leaving group or incoming nucleophile enables the reaction to proceed forward? (i.e. allows the carbon to dissociate from the Cl- and form a bond with OH- instead) Is there a way of theoretically determining which form (OH bound vs Cl bound) is likely to be in higher concentration in a solution that has been allowed to reach equilibrium?
I understand the example used in the video but when I try to do an sn2 reaction with OH- and H Br-h H3C I cant seem to figure out where should the OH- attack from.
+Professor Dave Explains You said it was named bimolecular because of the transition state. I dont see how the transition state is bimolecular. Could you explain? I thought it was called "SN2" because of the molecularity of the reaction - bimolecular, i.e. because there are 2 reactants (as opposed to SN1, where we have the fission of a single reactant). That's my personal understanding of what the molecularity of a reaction mean, but I'm probably wrong. Is the "bimolecular" or '2' in SN2 refering to some other kind of molecularity other than the molecularity of the reaction? Molecularity of transition state?
+jnxmaster it refers to the fact that the substrate is weakly coordinated to both the incoming nucleophile and the leaving group in the transition state of the reaction.
+Professor Dave Explains Hmm, okay. So if I understand you correctly, you're implying that the 'molecularity' of a 'transition state' is defined as the total number of bonds breaking or forming (to the central atom in question)?
Professor Dave Explains, It's strange because I've been googling for 20 minutes now, and I cannot find any information about the molecularity of SN1/SN2 reactions beeing defined by their transition state. All I can find are sites (Wikipedia and various .edu sites) categorizing SNx reactions either according to the >molecularity< of the >reaction< or according to the kinetic >order< of the >reaction< (which for an elemental reaction is based on, and is the same as; the molecularity of the reaction). There may be several accepted definitions out there, of course.
+jnxmaster as i understand it, whether it's SN1 or SN2, there's a substrate and a nucleophile. so if you're just looking at the reactants and don't know the mechanism, there's nothing to characterize them by. the key difference is that SN2 is concerted while SN1 is not, so to me, it makes sense to look at the transition state to differentiate them (which is also where the key stereochemical implications arise), but however you want to talk about it, as long as you understand the mechanism, is six of one, half a dozen of the other.
+Lucy Baston yes indeed, the LUMO on the substrate is the sigma antibonding orbital for the C-Cl bond, that's why as the nucleophile puts electron density into it, that sigma bond will weaken, as it is decreasing the bond order for that sigma bond. LUMO means lowest unoccupied molecular orbital, and you can always draw the MO diagram for the two atoms participating in the bond to find out what that orbital is.
How do we know that these reactions (sn1,sn2,e1,e2) occur ? I mean do we know about the flow of electrons based on experimental results or there are something like quantum chemistry behind them?
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This is the clearest explanation of Orgo I've ever seen, God bless you sir.
+Talia Havlin thanks kindly! spread the good word!
ruclips.net/video/iQDYfqsGUYY/видео.html
I couldn't have said it better myself.
@@ProfessorDaveExplains It means a lot. My professor just cant/wont explain things. It's a bit maddening.
I almost cried because I couldn't understand a word from my textbook+my teacher's lecture notes. You saved my life. Thank you so much.
ive literally been crying for 2 days because i cant understand any of this my test is in 2 days
Same
@@elhamhamidian6239 I took it and i failed lmfao
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God! Im sorry about that
I had my exam today
But it realy helped me solving the problems
I have recommended this channel for 150+ people who have been very satisfied with u...luv u man!!!!!
thanks for spreading the word!!
i am from india and me and my friends,we are preparing for the hardest exam conducting here and i have literally recommended my whole class so they can improve their organic too.......well 2020 going good so far
IIT-JEE? Right? Were these useful to you?
@@MasterSkywalker. ofc you dumb. Can't you understand what he says, easily.
Neet
@@MasterSkywalker. yeah to clear the basics
@@rahu844 jee
Its unbelievable how talented you are at teaching. I've been subscribed for about a year now. From general chemistry, to Bio II to cell bio, and now organic, its outrageous how clear and concise you are. Wish you the best success
2020 - Still going strong!
You the man, thank you for making OCHEM clear and understandable!!
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What's dat, how's dat, where's dat??????
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here from 2021- still going!
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Here in 2023
You are with no doubt one of the best guides for organic chemistry. Thank you so much for your hard work, I hope more videos will comes on the subject.
+Pascal Suissa thanks kindly! more content coming soon
Professor Dave is like the bad kid in school who joined the science club to make all the geeks feel dumb.
Daniel Lujano 😂😂😂😂😂😂😂😂😂😂😂😂😂 I laughed so hard man !!
One should make a musical about him😂
I always though he was like the “Rain Man” Of Science. In his spare time I see him saying things like “ Water Hurt Baby !”
THIS MAKES SO MUCH SENSE! Thank you. All your vids are helpful but these o-chem ones are exceptionally helpful.
This video really helps me immensely in medicinal chemistry to lay down the basic knowledge. Thanks a lot! 🙏🏻🙏🏻
Having videos like this while studying for the MCAT is just awesome. Thanks Professor Dave! Will be taking the MCAT in May of 2021!
How did it go ??
Ik I'm asking a bit late.... But still
Where you at ? Which medical College ?
Oh my goodness this is sooo well explained!! I was about to lose my mind after class
I've been studying for my ochem exam for 4 days now and was still so confused and felt like there was no way I could get this information down, but then someone suggested your videos and everything is so much clearer now! Thank you!
Same here in Taiwan~~
Wow...you make things crystal clear!
it is not always the case that if SN2 occurs on the chiral center it will necessarily invert the steriochemistry there. Because if the incoming nucleophile has a different Cahn-Ingold-Prelog priority from the leaving group.
Always jump to your videos if they come up in the search. Your the best! thanks!
Wow, first video I've watched of yours. You just clearly explained in 5 minutes what took me 2 hours to teach myself yesterday. New scriber here!
Professor Dave Explains and he explains it in *The EASIEST WAY possible*
Geez I love this channel so much !!!
its 2021... my organic chemistry lecturer could not help me, so I tried learning through youtube and oh well, thank you Prof.Dave - IT WORKED.
Thank you so much for fast, little tutorial :)
These videos are short and effective!❤❤❤
Thank you so much! Organic chem. was something I always hated as I thought its all about memorising, but you changed my perception,thanks alot again:)
this is awesome prof Dave. thank you very much.
For once I did not have my headphones in while watching your video and my partner hears your intro and realizes why I've been yelling "HE KNOWS ALOT ABOUT THE SCIENCE STUFF. IT'S PROFESSOR DAVE EXPLAINS!" for the past few days (at 2x speed of course).
Man. You saved my ass in this course. Keep the videos coming!
Im from the netherlands and I have a (dutch) OCHEM exam tomorrow (also with redox, addition- and condensationpolymerisation) but this video really made it a lot clearer even though its not in my native language! Thanks!
Perfect teacher for self-study students!
You just saved my life! Love your videos! They are more than good :)!
Always a hero prof. Dave 👍
you are an AMAZING teacher! thank you so much !
This is the clear explanation, you have really helped me, thank you
I swear this was the best thing ever. I was testing video after video but None of them was explaining wat everything means thy just went straight to an example
I don’t know how the hell you explained this complicated shit so well in 6min but I really do appreciate you
you are the best at explaining!thanks a lot
You are saving my o chem grade right now!!
5:12 when camera started moving, I thought that's my mind floating
Perfect explanation by the GOAT himself! 🥳🙌✨
Mr. Dave Sir. Nice way of clearly putting such complex stuff in a micro capsule. Am subscribing today. From ALUVA, Kerala, S. India. Am a Tutor Dear Sir
thanks for your tutorials
THANK YOU! your explanation was clear and understandable :D
OMG ❤ I love you for saving my life
professor dave, we love u
the best explanation i have ever seen
that was so clear and concise
Amazing and so helpful! Thank you!
I am watching this video from Bangladesh. This lecture is very nice.,,
Thank,s Professor Dave.
watching you for 6 mins is MUCH BETTER than listening to my professor talking shit on the board for 2 hours
Amazing video on explaining SN2 reaction! Just a question, at 2:27, surely you must mean the oxygen atom is the electron-rich atom? Not oxygen-rich atom? Keep up the great work Professor Dave :D
Whoops! Haha, yes.
This video is awesome!!!
very good explaination sir.thank you
Prof Dave Explains thanks for your help!! I remembered what attacks what !!
Loved the video, but I have 1 question... At 5:33, you said that an inversion would happen at a chiral center, but wouldn't the molecule you are referring to be achiral? It is attached to 3 identical hydrogens.
yep! so the groups will invert no matter what, but yes you only invert the stereochemistry if it was a chiral center to begin with.
Professor Dave Explains Okay, but if it was an achiral center, it wouldn't need to be inverted?
well the inversion will still occur, there just won't be any stereochemistry to speak of.
Professor Dave Explains Ah, okay. Thank you, this makes more sense :)
You are a genius, it is very very clear!
Awesome video. One question; you say that "the lowest unoccupied molecular orbital is 180 degrees from this carbon chloride bond". How are there any unoccupied orbitals? The carbon has four bonds already, and therefore a full valence shell, sp3 hybridized. So aren't all of the orbitals filled?
So when a nucleophile attacks an electrophile it has to put that electron density somewhere, and it can't put it in any of the ones that are full of electrons, so it goes to the orbital with the lowest possible energy that doesn't have any electrons in it yet. All chemical reactions are HOMO-LUMO interactions in that way! Check out my tutorials on molecular orbitals for more information, preferably the newer one.
I love his intro I sing along 100% of the time
Perfect explanation. I do think it would be helpful to show another rxn to more clearly depict the inversion of stereochemistry
you save lives professor.
what a beautiful explanation!
I salute you professor! This is awesome
Perfekte Erklärung. Perfect explanation :)
My teacher took 2 hour to explain SN2 and u make it clear in 6 mints
Hi Dave and thank you!! What do R and S stand for please?
Hi there! First off, your videos are amazing and so helpful. Thank you so much for helping students like me understand difficult concepts! Secondly, you mentioned that an inversion happens at a stereocenter but the compound drawn doesn't have a stereocenter. Just wondering why it had an inversion? Thank you!
well it will always invert, but if it's not a chiral center it won't matter!
Good job sir...and Congo ,you have won a subscription
This is an excellent video. Thank you.
Sir why the OH -ive does not attack Hydrogen bonded to carbon because it also has partial +ive charge?
good work mate
Really well explained! Very thankful to all the RUclips educators like yourself :)
One question I have regarding this: what property of the leaving group or incoming nucleophile enables the reaction to proceed forward? (i.e. allows the carbon to dissociate from the Cl- and form a bond with OH- instead) Is there a way of theoretically determining which form (OH bound vs Cl bound) is likely to be in higher concentration in a solution that has been allowed to reach equilibrium?
I have a doubt
Why LUMO(π*) lie back side of polar bond ❓❓ please tell
**Doubt
Professor can you explain why you have shown a reversibility sign in the SN2 reaction
Plz reply
SN2 reactions are generally reversible reactions, but their leaving groups affect how reversible they are
youre an amazing professor
That was a great explanation thank you soo much for explaining it so clearly 🙏😁
Thank you.
I love you, you're absolutely amazing.
Nice explanation!
Sir i have a doubt pls clarify it , should the leaving grp be a strong base or a weak base and why ? Pls explain 🙏🙏
your method is very good
Thanks, that was very helpful! :)
BEST 😍 explanation
LOVE From India 💛
I understand the example used in the video but when I try to do an sn2 reaction with OH- and
H
Br-h
H3C I cant seem to figure out where should the OH- attack from.
100000000000000000000000000000000 time better than my lecturer😮.. i did not understand what my lecturer was preaching
Love you jesus😊 of science. This matures sn2 soooo much simpler
SIR u explained it better than my subject teacher .I wish u could be our subject here in INDIA
What is the hybridization of the transition state carbons?
this is very helpful
+Professor Dave Explains You said it was named bimolecular because of the transition state. I dont see how the transition state is bimolecular. Could you explain?
I thought it was called "SN2" because of the molecularity of the reaction - bimolecular, i.e. because there are 2 reactants (as opposed to SN1, where we have the fission of a single reactant). That's my personal understanding of what the molecularity of a reaction mean, but I'm probably wrong. Is the "bimolecular" or '2' in SN2 refering to some other kind of molecularity other than the molecularity of the reaction? Molecularity of transition state?
+jnxmaster it refers to the fact that the substrate is weakly coordinated to both the incoming nucleophile and the leaving group in the transition state of the reaction.
+Professor Dave Explains
Hmm, okay. So if I understand you correctly, you're implying that the 'molecularity' of a 'transition state' is defined as the total number of bonds breaking or forming (to the central atom in question)?
Professor Dave Explains, It's strange because I've been googling for 20 minutes now, and I cannot find any information about the molecularity of SN1/SN2 reactions beeing defined by their transition state. All I can find are sites (Wikipedia and various .edu sites) categorizing SNx reactions either according to the >molecularity< of the >reaction< or according to the kinetic >order< of the >reaction< (which for an elemental reaction is based on, and is the same as; the molecularity of the reaction).
There may be several accepted definitions out there, of course.
+jnxmaster as i understand it, whether it's SN1 or SN2, there's a substrate and a nucleophile. so if you're just looking at the reactants and don't know the mechanism, there's nothing to characterize them by. the key difference is that SN2 is concerted while SN1 is not, so to me, it makes sense to look at the transition state to differentiate them (which is also where the key stereochemical implications arise), but however you want to talk about it, as long as you understand the mechanism, is six of one, half a dozen of the other.
So the wedge and the dashed H's also replaced each other in the transition state?
I love professor Dave
you are so good
Thank u so much professor
saved my day thank you very much :D
Thank you so much
awesome video!!!
Thank you professor Dave . Sir ,which organic book you are using?
What do you mean by highest occupied molecular orbital and lowest occupied molecular orbital..?
+Professor Dave Explains thanks 😃
Where we're u all these days ? The vid is two years old OMG!
i've just been here working hard! i've made a lot of stuff since these first tutorials.
Is the LUMO the antibonding orbital for the C-Cl bond? Is it an antibonding orbital? I think I have to be specific about what the LUMO is in my exams.
+Lucy Baston Sorry, that looks a bit interrogative! Fantastic video as always :)
+Lucy Baston yes indeed, the LUMO on the substrate is the sigma antibonding orbital for the C-Cl bond, that's why as the nucleophile puts electron density into it, that sigma bond will weaken, as it is decreasing the bond order for that sigma bond. LUMO means lowest unoccupied molecular orbital, and you can always draw the MO diagram for the two atoms participating in the bond to find out what that orbital is.
Professor Dave Explains Thanks! :)
How do we know that these reactions (sn1,sn2,e1,e2) occur ? I mean do we know about the flow of electrons based on experimental results or there are something like quantum chemistry behind them?
Are you asking how we know the structures of molecules? Check out my spectroscopy tutorials.
Sir How is C the chiral centre ? For a centre to be chiral it should have 4 different bonds right?
Bonds to four different groups, yes.