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1h Nmr & 13c Nmr

Discussion in 'Pre-Dental' started by ToothDoctor, Aug 12, 2002.

  1. ToothDoctor

    ToothDoctor Member

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    Hi...I'm new here! Could someone please help me out here?!?! I'm completely lost when it comes to figuring out how many peaks (and whether they are singlets, doublets, etc.) a certain molecule gives for 1H NMR. I'm equally lost when it comes to 13C NMR. I have read the Kaplan book over and over again and it seems greek to me. Does anyone have a clear simple explanation with a couple of examples? I appreciate it...Thanks.
     
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  3. ItsGavinC

    Dentist Moderator Emeritus

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    I don't have time for any explanations right now, but I can tell you that the odds of having any C NMR on the DAT are slim to none (I don't think I've ever heard of a question with C NMR!). There's a better chance of having H NMR, although I didn't have any of those either on my DAT.
     
  4. vixen

    vixen I like members

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    here's a quick ex:


    if you have R----CH2-CH3

    the h's on the ch3 are equivalent....therefore, they will all get the same splitting pattern...look 1 c away from them and how many H's do you see? 2 so 2=n and N+1=3 so its a 3H triplet. The CH2 has its n=3, so n+1=4 so its a 2H quartet.....

    if you had

    CH3-CH2-O-CH2-CH3

    the two methyl groups are equivalent here (equivalent meaning they're in the same chemical environment....right next to a CH2 and then and O) so the methyls would get One big splitting pattern of: 6h triplet

    the ch2's are also equal so they'd be a 4H quartet...

    hope this helps :)
     
  5. ToothDoctor

    ToothDoctor Member

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    Hey thanks! That does help! What happens if there in no adjacent carbon? For example.... CH3-O-CH3?
     
  6. vixen

    vixen I like members

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    CH3-O-CH3 would be a 6H singlet....n=0 here so n+1=1...singlet!
     

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