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Topic: Coupled and decoupled 13C spectrum  (Read 4548 times)

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Offline adamalt

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Coupled and decoupled 13C spectrum
« on: March 03, 2008, 07:57:14 AM »
Anyone knows how to sketch coupled and decoupled 13C Spectrum of:
  CH3COCH2CH3

Offline ARGOS++

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Re: Coupled and decoupled 13C spectrum
« Reply #1 on: March 03, 2008, 11:08:04 AM »

Dear Adamalt;

Could this be a start piont for you?:   "AIST:SDBS: 2-Butanone
(Enter your molecular formula & select 13C-NMR!)



Good Luck!
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Offline adamalt

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Re: Coupled and decoupled 13C spectrum
« Reply #2 on: March 03, 2008, 11:11:37 AM »
It helps a bit but I don't know what is the different between coupled and decoupled and how do you sketch them?

Offline azmanam

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Re: Coupled and decoupled 13C spectrum
« Reply #3 on: March 03, 2008, 11:15:56 AM »
start here for background.  1H NMR is important for understanding coupling in general, 13C NMR section begins to talk about your situation.  2nd link is further information about coupling and decoupling

http://www.cem.msu.edu/~reusch/VirtTxtJml/Spectrpy/nmr/nmr1.htm
http://www.cem.msu.edu/~reusch/VirtTxtJml/Spectrpy/nmr/nmr2.htm
Knowing why you got a question wrong is better than knowing that you got a question right.

Offline ARGOS++

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Re: Coupled and decoupled 13C spectrum
« Reply #4 on: March 03, 2008, 11:32:23 AM »
Dear Adamalt;

You will have to catch/read this from your textbook, because it’s too much to explain it in details.

Hints:
Most or several 13C are also relateted/bound to 1H and they will split the corresponding signal of the 13C nucleus.
So one 1H will split the signal of “its” 13C into a Doublett; two will split it into a Triplet, and so on.
Decoupling means that you can observe the 13C Signals “without” all this Splitting.

But you will anyway have to study it from the book.

Good Luck!
                    ARGOS++


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