I am not sure about the size of your molecule. You may be able to compute the required coupling constant using Gaussian.

It is probably worth repeating you experiment with a different set of experimental parameters, such as varying the delays and to use a different magnetic field strength, preferably higher, before attempting a QMech. calculation.

I am not sure about the size of your molecule. You may be able to compute the required coupling constant using Gaussian.

It is probably worth repeating you your experiment with a different set of experimental parameters, such as varying the delays and to use a different magnetic field strength, preferably higher, before attempting a QMech. calculation.

I am not sure about the size of your molecule. You may be able to compute the required coupling constant using Gaussian.

It I do not have any experience with the type of molecules that you have mentioned. However, it is probably worth repeating your experiment with a different set of experimental parameters, such as varying the delays and to use a different magnetic field strength, preferably higher, before attempting a QMech. calculation.calculation. Signals from quaternary carbons are sometimes suppressed due to inadequate relaxation delays. In addition, tuning the delays used to produce the coherence may alter the set of observable couplings.