Zhang,
I did complete analysis of the 1H NMR spectrum of labeled Urea in the presence of labeled 13C methanol. See attached file.
In the 1H NMR spectrum the NH2 protons of 15N labeled urea exhibit non 1st order splitting patters (complex, or 2nd order). This kind of complications I should roughly characterize as a ‘high order impurities’.
For this reason determination of all possible coupling constants cannot be determined accurately without involving an iterative calculation.
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 [mailto: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 Fri May 15 2015 - 03:27:33 MST