The 13C satellites are not symmetric about the 19F-12C peak due to the heavy
isotope effect. See Glen Facey's excellent post about it.
http://u-of-o-nmr-facility.blogspot.com/2012/10/isotope-effects-and-19-f-13-c-hmqc.html
Dan
From: main_at_ammrl.groups.io <main_at_ammrl.groups.io> on behalf of Weidong Hu via groups.io <whu=coh.org_at_groups.io>
Date: Wednesday, July 12, 2023 at 1:54 PM
To: main_at_ammrl.groups.io <main_at_ammrl.groups.io>
Subject: [AMMRL] Unexpected peaks of 19F NMR from CF3CH2OH
Hi All,
I acquired 1D-19F NMR of CF3CH2OH dissolved in CDCl3/CD3OD(2:1 v/v) on CP TCI
700 H&F-C/N-D probe (without 1H decoupling), and the spectrum is very confusing.
In addition to main triplet peaks, there are three minor triplet peaks (about
0.5% of main triplet). The positions of minor peaks are not symmetric to the
main triplet, and thus should not come from natural abundance of 13C-19F J
coupling. It is reasonable to see four minor peaks generated from one and
two-bond J couplings between 13C-19F, but they should be symmetric to the
main peak. I don't know how to explain the observed spectrum. Any suggestions
as what is going on? The spectrum is attached below.
Thank you,
Weidong
Dr. Weidong Hu
Department of Immunology & Theranostics
Beckman Research Institute
1450 E. Duarte Rd., Duarte, CA 91010
Tel: 626 256 4673, Ext: 63416
Fax: 626 301 8186
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#303): https://urldefense.com/v3/__https://ammrl.groups.=
io/g/main/message/303__;!!PvDODwlR4mBZyAb0!Q6COUuNDwkOM6kG9R6ox5PezVPAxzulj=
NjDGc500IKwjQOsOT_Tw38SnW1PrAKjQfIxPRy6yB173pYbv$
Mute This Topic: https://urldefense.com/v3/__https://groups.io/mt/100104757=
/7559972__;!!PvDODwlR4mBZyAb0!Q6COUuNDwkOM6kG9R6ox5PezVPAxzuljNjDGc500IKwjQ=
OsOT_Tw38SnW1PrAKjQfIxPRy6yB2JdjxiZ$
Group Owner: main+owner_at_ammrl.groups.io
-=-=-=-=-=-=-=-=-=-=-=-
Received on Wed Jul 12 2023 - 11:22:56 MST