Please, like, share, and comment to help promote this video! If you would like to support the channel, you can do so by either donating or becoming a member: Donate: www.organicchemistrytutor.com/donate/ Membership www.organicchemistrytutor.com/membership/
This is the first video on UA-cam I'm actually commenting on. I felt so lost attempting NMR, however after watching this video, I'm confident in attacking NMR spectra problems and knowing what first to look for. Thank you so so much Mr. Victor!
Wow, your first comment? You've officially leveled up in the UA-cam game! NMR spectra won't know what hit them 😉 I've got a few more NMR videos, you might wanna check those out as well for more detailed explanation of how to approach the problems and splitting patterns.
Thank you so much Victor, I wish our teachers would explain it this way instead of rushing + they didn't teach us the HDI and never used IR data on our problems so I got a new POV!
Thank you! But hey, comments and likes do help in telling UA-cam that folks enjoy my content and find it useful, so I really appreciate you pitching it!
Thank you for the explanation! In the last problem, why is there only a singlet for the aromatic ring? I thought there would be 3 signals since the hydrogens are not equivalent?
You're right, theoretically those are different signals. But they are all so similar to each other in terms of the chemical shift, that they overlap giving you what looks like one giant singlet.
Hi do you recommend any books/websites to practice spectroscopy questions? I'm struggling with NMR and MS. (I am subscribed to Victor's website already but I need more questions WITH ANSWERS).
When we talk about NMR and achieve sextets or other multiplets and the hydrogens are in different environments, wouldn't their J coupling be different? So how do we still in NMR get well behaving splitting patterns like this ?
Yes and no. If we don’t have any stereochemical restrictions, conformational locks, drastic differences in chemical environments, all J constants are going to be the same and you get nice pretty multiplets. You can get up to a nonet this way! But, as soon as we have any shenanigans of the sort I’ve mentioned above, we get different coupling constants and you start seeing crazy complex splitting.
32:19 sir, can you please explain, here in the 2nd aromatic ring , doesn't the positions that you have marked as d and d are same ( doesn't it be represented by a single signal) it's really confusing
The integrations are determined experimentally. They will be always given to you. If not, the molecule is simple enough and you can determine the structure without the integration values. But as I said, typically, integrations are provided as a number or as an integration line in older spectra.
@@VictortheOrganicChemistryTutor I was referring to one of the signals that made up the 4H where you indicated that its spitting pattern was a d/t (doublet/triplet).
@@anmariee5560 I understood you the first time. Listen to what I said in the video. This is not a quartet, this is an overlap of two different signals: a doublet overlapping with a triplet giving you a messy signal with 4 unequal peaks.
You either have an integration line where you can estimate the number of protons based on the hight between the horizontal parts (very old school), or your spectra are simple enough that you can do it without. Many of the examples I have in this video can actually be solved without the integrations given. It is a bad practice, but some instructors do it nonetheless.
@@VictortheOrganicChemistryTutor unfortunately no, I have to find out the molecular formula. Only IR with 3300 - v oh and 2800 v CH3. The OH on IR and NMR dublett ch3 (about 1ppm) should be 1.2 propandiol as a hint. But I have 2 times ch3 as dublett, how can be it 1.2 propandiol.
@@IkkaKaa Yeah... that doesn't make any sense. Not to mention that -OH doesn't split due to the hydrogen bonding. And the splitting constants at 3.65ppm don't make any sense either. If you have two constants, it's a complex splitting like a doublet of doublet, but not a quartet, which is a simple first order splitting pattern.
I’ve got quite a few of those, but yeah, stereochemistry is a hard topic. I’ll be making a few videos about it this semester, but I’ll be planning on circling back to this topic again next fall.
Please, like, share, and comment to help promote this video!
If you would like to support the channel, you can do so by either donating or becoming a member:
Donate: www.organicchemistrytutor.com/donate/
Membership www.organicchemistrytutor.com/membership/
I was cramming for my final ochem 1 exam and was watching your videos and you saved my grade! Now your saving me in Ochem2. Thank you!!!!
Awesome to hear I could help! I'll make sure to keep those helpful videos coming for OChem 2 as well.
Pls I need help on predicting the c13 nmr for salbutamol can you help
How'd your final in ochem2 go?
@@FaithEsohe-n6v Were you ever able to make a prediction?
@ great, passed with a B
thank you very much! this practice gave me a dipper and better understanding of H-NMR
You’re very welcome! Spectroscopy is one big puzzle, the more you do it, the better you become.
After watching your video i got confidence to solve nmr problems Thank you sir
Awesome!
What NMR problems did you solve?
I love your way of teaching 😊
This is the first video on UA-cam I'm actually commenting on. I felt so lost attempting NMR, however after watching this video, I'm confident in attacking NMR spectra problems and knowing what first to look for. Thank you so so much Mr. Victor!
Wow, your first comment? You've officially leveled up in the UA-cam game! NMR spectra won't know what hit them 😉 I've got a few more NMR videos, you might wanna check those out as well for more detailed explanation of how to approach the problems and splitting patterns.
How has working with NMR spectra been going?
Thank you so much Victor, I wish our teachers would explain it this way instead of rushing + they didn't teach us the HDI and never used IR data on our problems so I got a new POV!
You're very welcome! I always try to simplify things and make concepts more palpable for students.
SUCH AN UNDERRATED CREATOR
Thank you! But hey, comments and likes do help in telling UA-cam that folks enjoy my content and find it useful, so I really appreciate you pitching it!
Thank you for the explanation! In the last problem, why is there only a singlet for the aromatic ring? I thought there would be 3 signals since the hydrogens are not equivalent?
You're right, theoretically those are different signals. But they are all so similar to each other in terms of the chemical shift, that they overlap giving you what looks like one giant singlet.
I like solving spectroscopy problems. It's like playing chess but instead I am not getting checkmated by a 6 year old.
Hi do you recommend any books/websites to practice spectroscopy questions? I'm struggling with NMR and MS. (I am subscribed to Victor's website already but I need more questions WITH ANSWERS).
😂 can you solve this 0.9 ppm (dublet, 6h, j=6.7 Hz), 1.2 ppm(triplet, 1h, j=5.2 Hz), 1.45 ppm (Quartett, 2h, J= 6.7hz), 1.7 ppm( septett, 1h, J= 6.7 Hz), 3.65 ppm( Quartett, 2h, J=5.2/6.2 Hz)
This explanation is amazing wow thank you so much!
Glad it was helpful!
When we talk about NMR and achieve sextets or other multiplets and the hydrogens are in different environments, wouldn't their J coupling be different? So how do we still in NMR get well behaving splitting patterns like this ?
Yes and no. If we don’t have any stereochemical restrictions, conformational locks, drastic differences in chemical environments, all J constants are going to be the same and you get nice pretty multiplets. You can get up to a nonet this way! But, as soon as we have any shenanigans of the sort I’ve mentioned above, we get different coupling constants and you start seeing crazy complex splitting.
May I know if the formula can be applied for the NMR spectra for aromatic rings as well ?
best NMR vid
32:19 sir, can you please explain, here in the 2nd aromatic ring , doesn't the positions that you have marked as d and d are same ( doesn't it be represented by a single signal) it's really confusing
They are not the same for as long as groups X and Y are different. You might wanna watch theory tutorials before you go into practice 😉
H-NMR? More like "Heroically good videos; you're a star!" 🌟
31:57 I was confused by that little guy 😆
Haha thanks!
So great thank you ❤
Thank you 🎉
You’re welcome 😊
How do I know if DU corresponds to pi bond or cycle if IR absorption is not given?
You don’t. Each degree is either a pi bond or a cycle. Degrees of infatuation don’t tell you much on their own.
Life saver 🙇
🫶
Aprobé química orgánica en la universidad gracias a vos♥️🥹
💛
in exercice 7 why is the last oeak at t ppm a doublet split into a triplet if there are 4 signal not 3?
See other comments.
thanks prof
Where does the 1H, 3H and 6H come from? Like how do you know those are the numbers associated with the peaks?
The integrations are determined experimentally. They will be always given to you. If not, the molecule is simple enough and you can determine the structure without the integration values. But as I said, typically, integrations are provided as a number or as an integration line in older spectra.
@@VictortheOrganicChemistryTutorpls I have issues in predicting the hnmr and c13 nmr for salbutamol
Thank you
You're welcome :)
For the C7H6O3 question, the third signal appears to have four noticeable peaks. Why isn't it considered a quartet?
How does a quartet look like? What are the peak intensities in a quartet? And, most importantly, can you even have a quartet for an aromatic proton?
@@VictortheOrganicChemistryTutor So you're saying there are no quartet peaks in aromatic rings?
@@anmariee5560 To get a quartet, you need 3 neighbors with the same splitting constant. It's physically impossible for an aromatic proton.
@@VictortheOrganicChemistryTutor I was referring to one of the signals that made up the 4H where you indicated that its spitting pattern was a d/t (doublet/triplet).
@@anmariee5560 I understood you the first time. Listen to what I said in the video. This is not a quartet, this is an overlap of two different signals: a doublet overlapping with a triplet giving you a messy signal with 4 unequal peaks.
We dont have 6H 3H 1H etc given
You either have an integration line where you can estimate the number of protons based on the hight between the horizontal parts (very old school), or your spectra are simple enough that you can do it without. Many of the examples I have in this video can actually be solved without the integrations given. It is a bad practice, but some instructors do it nonetheless.
If we don't have IR how do we know that molecule has carbonyl or not
If you have CNMR, then yes, peaks around 180-220ppm are typically carbonyls.
@@VictortheOrganicChemistryTutorpls sir reply my msgs
Helpful video but in problem 3 wouldnt the H on the nitrogen have neighbours because of the CH2s?
NH and OH's don't split.
@@VictortheOrganicChemistryTutor Oh okay thank you so much! Your videos are incredibly helpful
I have A Trouble with this: 0.9 ppm (dublet, 6h, j=6.7 Hz), 1.2 ppm(triplet, 1h, j=5.2 Hz), 1.45 ppm (Quartett, 2h, J= 6.7hz), 1.7 ppm( septett, 1h, J= 6.7 Hz), 3.65 ppm( Quartett, 2h, J=5.2/6.2 Hz). I am not sure what mole... That. 1 butanol or 1.2 propandiol
Neither. Do you have a molecular formula?
@@VictortheOrganicChemistryTutor unfortunately no, I have to find out the molecular formula. Only IR with 3300 - v oh and 2800 v CH3. The OH on IR and NMR dublett ch3 (about 1ppm) should be 1.2 propandiol as a hint. But I have 2 times ch3 as dublett, how can be it 1.2 propandiol.
@@IkkaKaa Yeah... that doesn't make any sense. Not to mention that -OH doesn't split due to the hydrogen bonding. And the splitting constants at 3.65ppm don't make any sense either. If you have two constants, it's a complex splitting like a doublet of doublet, but not a quartet, which is a simple first order splitting pattern.
@@VictortheOrganicChemistryTutor understand. Thanks 🙏
Your videos are good but make more videos in stereochemistry sir from basics
I’ve got quite a few of those, but yeah, stereochemistry is a hard topic. I’ll be making a few videos about it this semester, but I’ll be planning on circling back to this topic again next fall.
@25.21, terminal carbon is D not C
Good catch 😀
LOVE Form PAKISTAN❤
في شرح مطيافية الكتلة ???
LOVE FORM PAKISTAN♥