How to Identify Molecules - Proton NMR: Crash Course Organic Chemistry #26

If you were given a chemical and told to identify it, how would you go about doing that? You could look at different factors like color, boiling point, melting point, or smell, but the answer still might not be clear. Thankfully, today we have a more precise, higher-tech way of identifying chemicals called Nuclear Magnetic Resonance, or NMR. In this episode of Crash Course Organic Chemistry, we’ll look at how NMR allows us to visualize a molecule as a spectrum, and what the peaks on the spectrum tell us about the structure of the molecule.

Episode Sources:
Mahdi, J. G. (2010). Medicinal potential of willow: A chemical perspective of aspirin discovery. Journal of Saudi Chemical Society, 14(3), 317-322.
Still, W. C., Kahn, M., & Mitra, A. (1978). Rapid chromatographic technique for preparative separations with moderate resolution. The Journal of Organic Chemistry, 43(14), 2923-2925.
Pastre, J. C., & Duarte Correia, C. R. (2006). Efficient Heck arylations of cyclic and acyclic acrylate derivatives using arenediazonium tetrafluoroborates. A new synthesis of the antidepressant drug (±)-Paroxetine. Organic letters, 8(8), 1657-1660.

Series Sources:
Brown, W. H., Iverson, B. L., Ansyln, E. V., Foote, C., Organic Chemistry; 8th ed.; Cengage Learning, Boston, 2018.
Bruice, P. Y., Organic Chemistry, 7th ed.; Pearson Education, Inc., United States, 2014.
Clayden, J., Greeves, N., Warren., S., Organic Chemistry, 2nd ed.; Oxford University Press, New York, 2012.
Jones Jr., M.; Fleming, S. A., Organic Chemistry, 5th ed.; W. W. Norton & Company, New York, 2014.
Klein., D., Organic Chemistry; 1st ed.; John Wiley & Sons, United States, 2012.
Louden M., Organic Chemistry; 5th ed.; Roberts and Company Publishers, Colorado, 2009.
McMurry, J., Organic Chemistry, 9th ed.; Cengage Learning, Boston, 2016.
Smith, J. G., Organic chemistry; 6th ed.; McGraw-Hill Education, New York, 2020.
Wade., L. G., Organic Chemistry; 8th ed.; Pearson Education, Inc., United States, 2013.

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Want to find Crash Course elsewhere on the internet?

[Slinder]

I really need all these spectroscopy videos to start being pumped out. This playlist has helped me so much with OCHEM this semester!

[kendalldoer]

I suspect this will soon become a very popular video and this comment will be lost to the sands of time...

[cheezmuffintv]

SUGGESTION:
Dear Crash Course Production Team,
One major reason I prefer your video series over the literally hundreds of others (other than a systematic approach and production quality) is because it provides background to the subject, which help clarify the quirks in it (eg, conventional current vs electron flow). I feel such stories of the modern versions of the subject, perhaps as a supplemental video can help us further understand what all we do, don't and can know, as well as inspire students to investigate certain lines of ideas.

Tl;dr- Great channel. Love cuz of background the stories provide. Maybe add similar stories of modern understanding and research?

[WaltRBuck]

NMR is one of my favorite things, and one of the things I'm absolutely bad at. I love testing the chemicals I make. I love testing them for purity too. Gas Chromatography is also fun.

[underdogg]

This is absolutely awesome - well-made, clear and concise. Thank you so much <3

[nathanturner]

Alphonse Elric in the background at the beginning 👀

[kindlez]

Great video, I believe you should have mentioned how to calculate unsaturation on a molecule it can really help

[maxmuenchow]

This was such a great easy to understand explanation and a great example. Thank you very much :)

[morcir.]

Omg this video helped a bit. Nobody told us how to identify molecules and our prof gave us a spectrum with a C15H14O2 molecule to identify. Like thx man but how do I do this?

[johnwielding]

Your unique dedication to this here endeavor is a blessing and an invaluable resource to the world of science. Your aid will enable the youth to discover their potential toward our live's work.

[steelformrarity]

Boy am I glad I passed organic chem with an A first time I couldn't go through that again, never again...

[sturmey]

Beautifully explained. I little bit of pause after the more complex concepts would allow following things more easily.
I guess you want to make the video compact, which is also important... But maybe just 3 seconds would help. I guess I can just pause it myself and replay several times as I have been doing haha. But is a bit stressful

[cameronfouche]

Are you guys eventually gonna do a video about aromatics?

[Xnibblet]

A little too quick for my understanding, but great information.

[XxKiokoxX]

WHAT ARE THE ODDS. A client wants a H NMR and I really not familiar with the equipment and you make this video. Wow

[leonardocanada]

Thank you for explanation this is very helpful.

[wbedard]

I'll bet that is some expensive solvent. It's also probably not possible to "reuse, reduce, recycle" it, either!

[kocengineering]

Thanks mam
U know I was dying for Ur next episode OMG
The time which takes waiting is very crucial to everyone in their life
Thanks again
Yes mam Schrodinger's equation is wierd

[fergimedia]

Such great info, awesome lesson ...
Love these videos ; from Winnipeg, Manitoba, Canada 😃

[sharaiahjoseph]

Fortunately we've moved on to a much high-tech analyticel technique
Me : and safe