i like this post (click again to cancel)
i dont like this post (click again to cancel) remove favorite mark from this question (click again to restore mark)

I'm trying to explain a missing HMBC peak, and having a coupling constant less than 10 Hz would do that nicely. It's a formamidine derivative with a 3 bond correlation N=CHNC The C is a quaternary carbon in a benzene ring. Any help would be appreciated.

asked Feb 04 '11 at 08:23

Toth's gravatar image


One Answer:
i like this answer (click again to cancel)
i dont like this answer (click again to cancel)

You may be able to compute the required coupling constant using Gaussian.

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. 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.


answered Mar 05 '11 at 07:01

sekhar%20Talluri's gravatar image

sekhar Talluri

updated Mar 05 '11 at 09:58

Your answer
Please start posting your answer anonymously - your answer will be saved within the current session and published after you log in or create a new account. Please try to give a good answer, for discussions, please use comments and please do remember to vote (login to vote)
toggle preview

powered by CNPROG