Signal intensity affected by long-range proton coupling?

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Hi, I'm looking for a theoretical explanation for the effect of long-range (proton) couplings on the signal intensity of the coupled peak. For example, we have a series of compounds in which we have two 2H 'triplets', one of which is also involved in long-range (5J) coupling - this 'triplet' is consistently shorter and broader than the other. We've confirmed the long-range coupling on moving to a higher field instrument and through a long-range COSY (COSYLR). Thanks in advance!

long-range; coupling

asked Apr 11 '14 at 01:25

doodlebugs
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Could this just be that the long range coupling is not resolved, and so is just broadening the lines a bit? That would reduce the peak height.

If you integrate the two triplets, are the integrals significantly different?

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answered Apr 14 '14 at 05:32

Pete Gierth
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Perhaps that's just it. The integrals are exactly the same for both. The finer coupling is visible once we move to the higher field instrument. - doodlebugs (Apr 14 '14 at 06:45)

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Asked: Apr 11 '14 at 01:25

Seen: 5,077 times

Last updated: Apr 14 '14 at 06:45

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