Organic Chemistry II - Solving a Structure Based on IR and NMR Spectra

In this video I determine a plausible chemical structure for an organic compound based on the given IR and H NMR spectra.
For a copy of the tables I used, click here: drive.google.c...

[@TheReck12]

Nmr is the bane of my existence, I'm never going to become a chemist

[@phatcat-st4gb]

I agree. NMR for me is like riding a bike without the seat, if you know what I mean.

[@kianna270]

I hate ittt so much, IR spec is so much easier and when I got to NMR I was like pls… god no…

[@arias8ale]

Honestly it’s so easy once you do the “I am ___H next to ___H’s it gets to easy

[@kaytlynsharp9640]

You have saved my life.. This is so much easier to understand than my professor.

[@TonyStJohn]

Thanks for the comment Kaytlyn! I'm glad to hear you found this video helpful. If there are any other topics you'd like me to make videos about feel free to email me at [e-mail]

[@priscacaesa6536]

I'm agree with you hahaha my professor so....................... Jshahakbsenhaksshwkjs

[@kiino213]

Man be saving lives even after 7 years

[@durmonov]

thank you for this video, I have an exam on how to find the structure of molecule using both nmr and IR, mass spectre, this video was what I searched

[@mrinabhk5917]

SIR, we need more videos with other examples... practicing more these problem with you makes it more easier.

[@roninissim3711]

reallllllll

[@NatalieNeff96]

I love how you broke everything down! Made it so much easier to understand, thank you so much!!

[@TonyStJohn]

You are very welcome!

[@5mb-5minutesbiochemistry67]

I watch your videos at 2021 and found this very useful. keep doing good !

[@shifaasaif2693]

exactly!! better than how my lecturer explained to me!

[@isacjoseph2875]

Just take my money. This is worth the time in gold.

[@samuelnyandwi3349]

Wooow these explanations are so good, like I am so happy I found this video! Thank you so much!!

[@_Babita-]

Tysm for explaining in a very easy and basic manner. It ready helped me a lot.❤

[@roninissim3711]

I love you this is the best EVER!!!!!!! very helpful I wish you the best in life Tony I can't thank you enough.

[@joshjulian6793]

This was very helpful! I'm looking forward to more videos :)

[@shifaasaif2693]

Thank you so much😭❤️❤️ i have a final exam tomorrow and i was really worried, i get it know. Anddd i like your pen

[@jacktam5855]

You saved my life. Thank you very much.

[@laylabitar5853]

Wow you walk through this with great explanation. Do you have more videos with these types of problems ?

[@stinkydogguy12]

Oh wow this video has lots of views! You were a great professor at WWU. Keep it up!

[@rickyscollegescene3484]

view digger be gone

[@muazmustafa1655]

This is just what I needed to review for my final tomorrow. Thank you for the helpful video

[@TonyStJohn]

You are very welcome! Good luck on your final!

[@mpsenicka8792]

No because there are no H's on the adjacent carbon. The H's on the ring are on non-adjacent carbons and therefore are too far away to cause splitting.

[@user-hy3yu4wx1j]

In this video I determine a plausible chemical structure for an organic compound based on the given IR and H NMR spectra.

[@radhamanoharrs]

Very much helpful to learners like me thank you for such a great video

[@TonyStJohn]

You are very welcome! Thank you for the nice comment!

[@AnaPaula-yb3ui]

Love u Tony, thanks so much

[@joshg.6536]

Great content! was very helpful.

[@hkharis07]

Keep it up, Dr John. Well explained.

[@HD15153]

Thank you for the great video. I learned many things from you.

[@jurevirtic3804]

wouldnt it be more plausible if the ehtyl and methyl groups were swapped, since the CH3 would feel other H in the ring and would have some noise if not even a triplet?

[@LoveAustralian]

My professor gives us the NMR data, but asks us to figure out IR ourselves first, it isn’t given. Also we have to memorize all of the NMR and IR numbers, we don’t have a chart given to us to use on the exam. I have yet to find a video that explains how to come up with an plausible organic structure using only given NMR data to come up with IR data.

[@TonyStJohn]

Morgan Gill that will definitely make it more challenging! But, depending on the compound there is a lot of good info you can get from just the NMR. If you want to send me an example problem I can take a look today and make a new video for you! You can email me at [e-mail]

[@YataLock98]

Same here ,I have to memorize all the HNMR, CNMR ,IR , Mass Fragmentation values , do they see us as machines ?

[@LoveAustralian]

Thank you for replying! I never saw it! I finally got it after I looked at it a bit more, and now it’s easy! I ended up with an A in the class, PTL. Thanks for uploading this video!

[@foxyalchemist8271]

@@LoveAustralian Would you be able to give a few pointers on how to solve these problems? If not, could you direct me to a KZbin that can? I am currently in the same boat as you were. Thank you

[@LoveAustralian]

Afiya Fox I’d have to see an example problem, it’s been 8 months since I last did NMR and IR! However, I’m sure this professor would be willing to help if you emailed him! He said his email is [e-mail] Best of luck! (As for recommended KZbin videos, I actually pulled up charts on google of NMR to IR, if I remember correctly, and practice problems on Chegg of IR to NMR and that helped too!)

[@alirezaghazavi]

you made me pass my exam god bless

[@ripcactusify]

Why is it sp3? Sp2? I'm not understanding this part. You just kinda stated it.

[@bottomtext251]

What if you do not have labelling for your NMR-spectra?

[@debradias8288]

In examination, they don't give us the chart.I'm so terribly confused😨

[@iranovianti6839]

This is just what I need.. thank you so much..

[@TonyStJohn]

You are very welcome! I'm glad it was useful.

[@michellla93]

Do you have a pdf of the sheet you were using with those values?

[@creativefruittree3480]

may God bless your soul you helped me so much

[@TonyStJohn]

You are welcome!

[@olawaleadeniji1412]

You're a superman... Thanks alot

[@TonyStJohn]

Ha! I don't know about superman, but you are very welcome!!

[@leonardodicaterina7675]

Really clear and quick, but I think you could manage finding out the products that comes out with the tautomerization process, to be sure that is effectively a carbonyl group, and also to avoid any possible viewer doubt about the other signals. that's my opinion

[@rawanwaleed6788]

So helpful thanks a lot!!

[@maryamahmad805]

U ARE AMAZING :) thanks a lot

[@TonyStJohn]

You are very welcome! Good luck with your studying!

[@nebojsasimic6248]

Hi Tony, I have to admit, a very nice explanation. However, I wonder how you know that the propyl group and methyl group at 2.3 ppm are not swapped? The shift difference between CH3-C=O and CH3-Ph is very small (2.1 and 2.3 ppm respectively, according to your shift table) and, in my experience, the shift alone cannot be decisive in such cases. Is your structure based on some additional spectra, e.g. HMBC?

[@TonyStJohn]

Hi Nebojsa Simic! I think the easiest way to answer your question is to look at the integration and splitting patterns of those peaks you are questioning. The peak that I have assigned as the aromatic methyl group integrates to 3H and is a singlet, while the peak that I have assigned to the CH2 group next to the carbonyl carbon integrates to 2H and is a triplet (splitting from the adjacent CH2). Does that answer your question? Hopefully it helps!

[@pi2745]

Me too i feel the same .. since ch3 can give s at 1 if only propyl was para to ester

[@ahbak47]

Can't we switch the R groupe? Ch3 with co and o . And ch2ch2ch3 in the para side?

[@missy8659]

hi, love the video. i'm confused by one small item though, why is the methyl group attached to the benzene a singlet? is it not affected by the neighbouring protons on benzene?

[@mariaemiliagomespereira3455]

It’s not affected because the other hydrogens are not 3 bond neighbors to the ones in the methyl

[@a.n.5609]

Would degrees of unsaturation be necessary in validating the structure? If so, why am I getting a large number when calculating the d.o.u. ?

[@zee029]

Akwi Njoh I believe you’d get 5 - this accounts for 1 ring, 3 pi bonds in the ring, and 1 double bond in the carbonyl group

[@shobhitshrivastava1005]

If 2 imine group is present and both attached with benzene ring. What would be expected peak. In IR

[@HimanshuSharma-xn6uc]

They don't give us table any way to memorize it

[@atulksharma20]

its sooo Easy thanks

[@rociolopezdomene9567]

You are great!! thanks :D

[@ajamanadair2692]

I have several IR spectrum gotten from my research which I have grafted polyacrylamide onto Hydroxyethyl cellulose how to completely assign the spectrum

[@dopaminegirl8675]

Thank you ❤️

[@EliwoodX8]

Gracias! Mis profes no tienen idea como explicar

[@quantum7401]

I have some 14-day old urine in the refrigerator, I want to drug screen it via GC/MS. Will the results still be valid? What is Forensic protocol, in regards to length of time a sample is valid?

[@kikakarbasi9059]

tnx a lot for your useful video..how can I access to your handout?

[@Kerwyn204]

can you pls put the copy of the problem again, the link doesnt work. thank you

[@ahabfarhan3547]

thanks u soo much ... u save my life

[@TonyStJohn]

Haha, you are welcome Ahab! Glad you found it helpful.

[@muafiamushtaq7080]

Assalamualaikum Tony. I want to get solution of alkyl halide Spectra's by NMR.. I have to present it by next week. Can you please help me..

[@sonawanechanda9961]

Plz explain uv spectroscopy Structures of dien & enone plz

[@mariaiqbal5519]

I have no idea about nmr (H1, C13), no base, this subject is new to me. But I have a spectra of my compounds, how can I solve it?

[@TonyStJohn]

Hi Maria, if you are able to email me your spectra I would be happy to make some easy explanations of the theory of NMR! Just email me at [e-mail]

[@mariaiqbal5519]

okay

[@hysteria697]

We are doing this type of stuff in Ochem 1 and we don't get a table!!

[@latestlive5925]

I dont know sir.......how explain ???????

[@faraha2285]

Hello Tony. Usually at our exams what we get, is the molecule and we have to give the chemical shift, Multiplicity (s,d,t,q) and the integration (1H, 2H, 3H etc). I have been looking through youtube without finding an example that shows how to solve such problem. Also we get the nmr spectra by itself without an IR. Can you please help?

[@TonyStJohn]

Hi Farah, of course! Do you have a specific molecule example that you'd like me to make a video of? I will try to find something to post tomorrow in any case! Here is another video that I recently made that just deals with an NMR spectrum that might help as well: kzbin.info/www/bejne/kJSxepSonrKeicU

[@faraha2285]

Oh You answered. Thank you so much. Well, I have 2-3 examples actually from previous exams with the answers as well - that doesn't help me that much, as I want to understand it and solve it myself. Do you have an e-mail I can send you these examples? Thank you again for replying ...

[@TonyStJohn]

Hi Farah, you can email me at [e-mail]

[@kavyapatel4564]

The -CH3 attached to benzene ring should have (2H,d) and not singlet is'nt it?

[@TonyStJohn]

Nope! The label (2H, d) would mean the integration is 2, and the splitting pattern is a doublet. Since the -CH3 attached to the benzene ring has 3 H's, it should integrate to 3 (3H), and since there are no H's on the carbon in the ring that the -CH3 group is attached to there will be no splitting and will therefore be a singlet (3H, s). Hope that makes sense!

[@kavyapatel4564]

thank you sir, I understood my mistake. There are 3H's typing mistake and doublet i took the adjacent carbon splitting. Thank you sir for your reply and explanation.

[@rakeshsahu1893]

acc. to final structure there must be a quartet (ch3-ch2-)

[@Kaiserland111]

The chain in question is actually H3C-CH2-CH2- so the middle carbon's hydrogens are split by both the 3 hydrogens to their left and the two to their right. Thus it would be a multiplet, not a quartet.

[@learnwithhafizaarsala5519]

informative

[@asdfg-wu1tu]

1759 is HC=N

[@Orgophile]

cool!!

[@katiagaspar7676]

Helpful

[@aneesabdullah3418]

can I contact you Tony St. John, I have some problem in explanation of my FTIR chart

[@TonyStJohn]

Hi Anees! Feel free to email me at [e-mail]

[@aslit5314]

I liked that pen

[@tugceklnc7640]

Soru göndersem cevaplar mısınız

[@KenyaTeam2011]

How do you know there is a ring and not a double bond?

[@TonyStJohn]

Hi Allison, the peak at 1600 in the IR spectrum tells us there is a ring!

[@KenyaTeam2011]

Thank you!

[@TheKhanViction]

Also, if you do the HDI you can kind of guess if it is a ring if it is greater than 4.

[@taohidahmed3143]

It is very very hard

[@alchemical1988]

good please sent me the problem of this?

[@zahraachemists8166]

محمد الكيمياوي عربي مفتهم الماده خويه

[@Mipso96]

I'm so fcked for tomorrow lol, I hate how we have to memorize all the fragments, CNMR, HNMR spectra values like can't we have a chart or something? :'(

[@navs8098]

hi, where could i get a copy of that table?

[@TonyStJohn]

+Nav Seira Here is a link to the tables! drive.google.com/open?id=0BwOceMKQTVFxRTh1Szl4aTh0eE0

[@navs8098]

***** thanks!

[@esmeraldadenisse2179]

If only we could use a cheat sheet

[@mrkillua5037]

Could you do one just from analytical data, no graphs ?

[@colorpharma2123]

Yes

[@claudiasiete]

♥

[@Mentosman321]

Praise Be Tony St. John, Savior of the Orgo Students!

[@lakshmiprasanna8294]

Sir I am a research scholar, I have lot of confusion in nmr interpretation and IR interpretation ,can you help me

[@ghaziazouni8766]

why/

[@shubhammore4986]

Sir C9H11BR

[@callmehoo]

Sir, is it possible for you to email me the reference table that you use in the video? Please. I really need it

[@TonyStJohn]

If you click on "Show More" in the video description I have posted copies of the reference tables!

[@sheabear4239]

Me and all my homies hate NMR

[@maxwellnorton6482]

im so high

[@alex-pt2hd]

this did not help at all