Date: Tue, 19 May 2015 19:58:44 +0000
Hello:
I would like to take this opportunity to thank all people for answering my question.
Clemens Anklin (Clemens.Anklin_at_bruker.com<mailto:Clemens.Anklin_at_bruker.com> )
Xinfeng Gao (xgao_at_indiana.edu<mailto:xgao_at_indiana.edu> )
Jun Gu (jungu_at_sas.upenn.edu<mailto:jungu_at_sas.upenn.edu>)
Novruz Akhmedov (Novruz.Akhmedov_at_mail.wvu.edu<mailto:Novruz.Akhmedov_at_mail.wvu.edu>)
Joseph Barchi (barchij_at_mail.nih.gov<mailto:barchij_at_mail.nih.gov> )
Stefan Berger (stberger_at_rz.uni-leipzig.de<mailto:stberger_at_rz.uni-leipzig.de> )
Alan Brown (abrown_at_fit.edu<mailto:abrown_at_fit.edu> )
Dan (holmesd5_at_msu.edu<mailto:holmesd5_at_msu.edu>)
Sebastian Kemper (sebastian.kemper_at_tu-berlin.de<mailto:sebastian.kemper_at_tu-berlin.de> )
Alan Kenwright (a.m.kenwright_at_durham.ac.uk<mailto:a.m.kenwright_at_durham.ac.uk> )
Ryan T. McKay (rmckay_at_ualberta.ca<mailto:rmckay_at_ualberta.ca> )
Virginia W. Miner (gina_at_acornnmr.com<mailto:gina_at_acornnmr.com> )
Tadeusz Molinski (tmolinski_at_ucsd.edu<mailto:tmolinski_at_ucsd.edu> )
Matthias Niemitz (niemitz_at_perchsolutions.com<mailto:niemitz_at_perchsolutions.com> )
PERRY PELLECHIA (PJPELLEC_at_mailbox.sc.edu<mailto:PJPELLEC_at_mailbox.sc.edu> )
Urea is an A2A2'XX' spin system with chemical shift but not magnetic equivalence.
The simulated spectra are very similar to the experimental results using the following coupling constants.
1J(H,N) 2J(N,N) 3J(H,N) 4J(H,H)
86.8 5.0 1.8 1.0 Hz (Novruz G. Akhmedov)
88 4.6 1.8 1.0 Hz (Xinfeng Gao)
86.7 4.8 1.7 1.0 Hz (Matthias Niemitz)
Attached are pictures from Matthias Niemitz who did not post them to AMMRL.
Simulated spectrum (red) vs. the experimental one (blue) with the difference (green)
If you have any NMR questions, just ask AMMRL!
Weixing Zhang
From: Zhang, Weixing [mailto:Weixing.Zhang_at_STJUDE.ORG]
Sent: Thursday, May 14, 2015 1:53 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
(image/png attachment: Urea-15N_PERCH_FIT_15N_spectrum.png)
(image/png attachment: Urea-15N_PERCH_FIT_1H_resolution_enhanced.png)