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    Hey

    So I'm having some problems with some NMR spectra I find very puzzling.

    Basically I have a Ph3P-BH3 compound, and two spectra.

    Both are B11 spectra, but one is proton decoupled and one is not. On the decoupled spectrum I have what I expect. A doublet, indicating the presence of the adjacent phosphor group.

    But on spectrum which isn't decoupled I have a sextet. This is confusing for me because there are only 3 protons and 1 phosphorus atom for the Boron to couple with. So why do I have a quintet not a sextet?
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    Also - What is meant by a 31P[1H] spectrum? A proton decoupled 31P spectrum?
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    (Original post by Argnen)
    Hey

    So I'm having some problems with some NMR spectra I find very puzzling.

    Basically I have a Ph3P-BH3 compound, and two spectra.

    Both are B11 spectra, but one is proton decoupled and one is not. On the decoupled spectrum I have what I expect. A doublet, indicating the presence of the adjacent phosphor group.

    But on spectrum which isn't decoupled I have a sextet. This is confusing for me because there are only 3 protons and 1 phosphorus atom for the Boron to couple with. So why do I have a quintet not a sextet?
    I imagine that the coupling constant is different for the two atoms and what you are observing is a quartet of doublets ...
 
 
 
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