Dear all,
I bumped into a question about carbon chemical shift for a carbon
between two nitrogens as the following:
1. para-something-Ar-N=C=NH
2. para-something-Ar-NH-CN
ACD labs indicated that the 2nd layout is the most stable structure,
with a chemical shift of around 119 ppm. The chemical shift calculated
for the 1st is around 140 ppm. However, when looking into the protocols
it used for calculation the 1st one, none of the database structures is
close to what it is.
While we are running HMBC to find out which one is most likely to be the
right structure, I am wondering if anyone who have bumped into this kind
of structure before can kindly tell me what the expected carbon chemical
shift in these two structures.
Any suggestions are highly appreciated.
Thank you.
Wei Li
Wei Li, Ph.D.
Assistant Professor and Director of NMR Facility
Department of Pharmaceutical Sciences
College of Pharmacy
University of Tennessee Health Science Center
847 Monroe Ave., room 327A
Memphis, TN 38163
901-448-7532 (Phone)
901-448-6828 (FAX)
Received on Tue Aug 09 2005 - 15:13:54 MST