complex splitting

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    I have a hydrogen nmr and I think it fits nicotinaldehyde but i don't understand the aromatic splitting pattern, there is 3 doublet of doublets and a doublet of triplets, would anyone be able to break it down for me? thanks
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    Can you post a picture of the spectrum?
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    (Original post by alow)
    Can you post a picture of the spectrum?
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    (Original post by jacksonmeg)
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    For nicotinaldehyde I would expect the aromatic protons to show a singlet, two doublets and a doublet of doublets.

    But this is not taking into account aromatic allylic coupling ... so I'll shut up!
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    (Original post by jacksonmeg)
    I have a hydrogen nmr and I think it fits nicotinaldehyde but i don't understand the aromatic splitting pattern, there is 3 doublet of doublets and a doublet of triplets, would anyone be able to break it down for me? thanks
    Certainly looks about right for nicotinaldehyde.
    The aldehyde is very obvious and the others all look aromatic.
    There appears to be a large amount of "W"-coupling, really quite difficult to try to assign, it might be doable if you know any numbers for the coupling constants?

    Theoretical spectrum looks similarish, with okay shifts, but clearly hasn't quite accounted for all the couplings
    https://atb.uq.edu.au/molecule.py?nm...0225#panel-nmr
 
 
 
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