Zhang,
In urea if both nitrogen are labeled (15N) then the 1H NMR spectrum will show a triplet 2J(H,15N) ~90 Hz. The doublet could be due to 2J(15N-15N) coupling constants between labeled nitrogen's. The magnitude of this coupling must be small (4 -5Hz).
If you could send me the FID's of both spectra then will be interesting to identify all possible couplings;
I need the FID's of 15N-labeled urea: (1) FID's of 1H NMR spectrum of labeled urea (no decoupling from 15N);
(2) FID's of 1H NMR spectrum with 15N decoupling (3) FID's of 15N NMR spectrum with 1H decoupling .
The expected couplings are as follows: 1J(H-15N)
2J(H,H)
4J(H,H)
2J(15N,15N)
Thanks,
Novruz
Novruz G. Akhmedov, Ph.D.
NMR Research Associate
Director of NMR Facility
NMR website: http://nmr.wvu.edu
West Virginia University, Department of
Chemistry, 217 Clark Hall, PO Box 6045
Morgantown, WV 26506-6045, USA.
Phone: 304 293 0918; Fax: 304 293-4904
________________________________
From: Zhang, Weixing <Weixing.Zhang_at_STJUDE.ORG>
Sent: Thursday, May 14, 2015 2:53 PM
To: ammrl_at_ammrl.org
Subject: AMMRL: 15N and 1H spectra of 15N-labeled urea in DMSO
Hello All:
I recorded 1H and 15N spectra of 15N-labeled urea in DMSO.
Both 15N-decoupled 1H and 1H-decoupled 15N spectra have single peak.
Without decoupling, both 1H and 15N spectra show a small splitting of ~4 Hz (see attached pictures).
Does anybody have an explanation of the splitting pattern?
Thanks,
Weixing Zhang
St. Jude Children's Research Hospital
Memphis, TN 38105
Received on Thu May 14 2015 - 15:24:25 MST