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Another BS NMR question

Discussion in 'Pre-Medical - MD' started by Luthertaketwo, Mar 16, 2004.

  1. Luthertaketwo

    Luthertaketwo Membership Revoked
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    http://www.chem.ucla.edu/cgi-bin/webspectra.cgi?Problem=bp15

    This PNMR doesn't seem right. Shouldn't the PNMR show 3 singlets, 1 doublet, 1 triplet if their "supposed solution" is correct? The only way you would have got that answer is if you "ran with the CNMR" and ignored the PNMR. That's ******ed.
     
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  3. acab

    acab Senior Member
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    The 2 Hs on Cs adjacent to the C attached to the Br are more deshielded so are further downfield. So those 2 Hs shouls show s triplet further down. The other 2 Hs on the ring father from the C with Br should show a triplet a bit more upfield from the previous triplet. Finally the 3 Hs on the CH3 show 1 peak way upfield.

    Main point: the 4 Hs on the ring are not equivalent. The closer to an electronegative element, the more deshielded the h will be.

    Hope this answers your questions.
     
  4. Luthertaketwo

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    Not exactly. Heh. How can "those 2 Hs shouls show s triplet further down"when one doesn't even have any vicinal hydrogens and the other has only one(should be a doublet)? Er. It should be a triplet, a doublet, and 3 singlets.
     
  5. Luthertaketwo

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  6. Luthertaketwo

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    Hrmm. I guess so. :idea:
     

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