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coupling constant (spin-spin)

(1/1)

Morphic flip:
If J 1(H, 13C) = 208 MHz
Where do I get the figures/info needed to work out a value for 1 J (31P - 53Cr) ?
Can`t can`t find reference for what to use  ???


Another problem I have  ::) is using pascal`s triangle,
how do I work out "a spin 1/2 nucleus coupling to a one spin 3/2 nucleus, how many lines the resonance is of the spin 1/2 nucleus split into, and the relative intensities"

    Multiplet      Intensity Ratio
     Singlet                 1
     Doublet              1:1
     Triplet               1:2:1
     Quartet            1:3:3:1
     Quintet           1:4:6:4:1
     Sextet          1:5:10:10:5:1
     Septet        1:6:15:20:15:6:1

Dan:

--- Quote from: Morphic flip on May 24, 2006, 07:44:44 AM ---Another problem I have  ::) is using pascal`s triangle,
how do I work out "a spin 1/2 nucleus coupling to a one spin 3/2 nucleus, how many lines the resonance is of the spin 1/2 nucleus split into, and the relative intensities"


--- End quote ---

Pascal's triangle only works for coupling to spin-1/2 nuclei.

For coupling to nuclei with I>1/2 (where I is nuclear spin), you must consider the number of space quantisations of of mI. The number of these space quantisations is 2I+1 - the signal is split into this number of peaks of equal intensity (just as coupling to one I=1/2 nucleus, where 2I+1 = 2, splits the signal into a 1:1 doublet).

Just to clarify, if you couple to several I>1/2 nuclei, you will have to do a tree/stick diagram or something similar to work out the intensity ratio.

So to answer your second question, coupling to one I=3/2 nucleus you will give a 1:1:1:1 quartet.

As for your first question, I have no idea

Morphic flip:
Thank`s for the well explained reply.
So if the quartet is 1:1:1:1, I take it the intensities are all the same?
Cheers.

Dan:
yeah, 1:1:1:1 is the intensity ratio of the peaks in the quartet

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