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Topic: H NMR  (Read 4487 times)

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Offline Cait

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H NMR
« on: February 21, 2014, 11:39:27 AM »
    I'm trying to predict the number of H NMR signals that would be produced by cis-1,2-dimethylcyclopropane. I know that the protons attached to the methyl substituents are in  equivalent environments and thus would produce one signal. I also think that the protons attached to the first and second carbon would produce one signal because they appear to be enantiotopic.
      However, I'm having trouble deciding whether the two hydrogens on the third carbon would produce one or two signals. I think they may be diastereotopic because if each of the hydrogens were replaced with another group, a chlorine atom for example, a pair of diasteromers would result. This would indicate that the protons would produce two signals, though I'm not entirely sure if I'm correctly identifying the hydrogens as diastereotopic. Could someone tell me if I'm approaching this problem correctly?

Offline PhDoc

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Re: H NMR
« Reply #1 on: February 21, 2014, 02:58:59 PM »
Have you made a model? If not, make one. This is not a trivial exercise, and it will help you in understanding different types of protons.
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Offline zsinger

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Re: H NMR
« Reply #2 on: February 21, 2014, 03:25:58 PM »
Honestly, I learned to get good at NMR on Youtube.  While there is much junk, there are also an many good videos.
                       -Zack
"The answer is of zero significance if one cannot distinctly arrive at said place with an explanation"

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