11.03 The Pulsed NMR Method

Continuous wave NMR methods. Pulsed NMR methods including the shape of the pulse in the time and frequency domains and advantages over CW approaches. A musical analogy for the pulsed NMR method.
00:00 Introduction
01:06 The Continuous Wave NMR Experiment
02:06 The Pulsed NMR Experiment
03:04 A Musical Analogy

[@maraganina]

Excellent Video! Great explanation and presentation.

[@paulyliu1326]

Very intuitive and well explained! Thanks!

[@ottoomen5076]

Nuclei spin-flip in pulse NMR is caused by the absorption of energy from the magnetic field oscillating at radio frequencies. CW-NMR uses the absorbance of radio waves. (minor detail) good presentation.

[@chemstreet3036]

Nice video! The example of the guitar strings is very useful :)

[@med9371]

Thank you so much for this video, I was extremely confused over how different chemical shifts could be seen, is this the same method used in MRI?

[@adosar7261]

But isn't relaxation so fast that the emitting photons (from relaxation) meet the initial photons so we actually have the same frequency spectrum again? Thanks in advance.

[@vanfidel]

Are you sure about this continuous wave explanation? My understanding of continuous wave is that the frequency is fixed and the variation is in the magnetic field strength.

[@mevansthechemist]

I believe it can be done both ways, but I'll admit I didn't read up on this. Intuitively, my thought was that it would be easier to vary the radiofrequency using an RF generator than it would be vary the magnetic field strength...I could be wrong!
Either way, CW NMR is, to my knowledge, pretty much dead in chemistry laboratories.

[@med9371]

Michael Evans you can do either

[@gautamisr869]

@@mevansthechemist Yes the frequency can also be varied with constant magnetic field. But varying at such high frequencies is a difficult task. So , magnetic field is varied with keeping frequency constant.

[@stringroller2]

Easy explanation ! However couldn't understand why the guitar has only five string!!

[@mevansthechemist]

Because...I don't play guitar! :-P Thanks for watching.

[@Niki0815]

A normal guitar has 6 strings, but good video anyway 😀

[@Seorful]

Please dont call it RF light. Light is per definition only the for humans visible part of electromagnetic radiation. Just call it electromagnetic radiation.