Just for clarity, I am curious about the small sattelite peaks, on either side of the main CDCl3 peak in proton NMR of CDCl3... Not in C13 NMR. I understand the peak splitting.
Thanks!
I would guess that it is for the same reason that all other peaks proton signals have satellite peaks. About 1% of the carbon in the sample is 13C, so that would split the singlet into a doublet since there is normally no 13C decoupling for proton spectra.
Oh yes.. true.. 13C has a natural abundance just over 1% and the major isotope (12C) is not NMR active so very little of the proton signal is coupled. The coupled signal appears as small satellite signals either side of the main uncoupled signal
you can verify the 13C satellites by their distance from one another. It should be ca. 209 Hz. This is the coupling constant 1JCH. The centre of this doublet should be at a slightly lower frequency than the CHCl3 signal (isotope effect).
In Fourier transform NMR there are no spinning side bands so it is easier to identify the 13C satellites. You should also note that the 1JC-H coupling constant [209 Hz] is related to the 1JC-D coupling {32 Hz] seen in the 13C spectrum of CDCl3 by a factor of 6.51 [the ratio of the gyromagnetic constants of H vs D.]. In addition the !J C-H coupling is related to the hybridization of C in CHCl3. The index of p = 500/[1JC-H] -1 which works out to 500/209 - 1 =1.4. The hybridization of C in CHCl3 is thus sp^1.4, not sp^3 as stated in many General Chemistry textbooks.
Cite
Ludger Ernst
Technische Universität Braunschweig
As to Donald Clark‘s answer: it is not true that there are no spinning side bands in FT NMR. It is only true if you do not spin the sample tube during the acquisition of the FID.
Cite
Similar questions and discussions
How to remove DMF completely after completion of reaction ( DMF used as solvent in reaction)?
Question
73 answers
- Avula srinivasa rao
I proceeded one reaction with DMF used as solvent, after completion of reaction i did workup with water and ethyl acetate system. I observed some amount of DMF still present in the organic layer. can you please give some suggestions how to remove DMF completely.
How to show integration and peak values in stacked spectra in MestReNova?
Question
3 answers
- rajeev chand Nishad
Hello experts,
I am using MestReNova software for NMR data processing and plotting, but I am unable to find out an option by which I can show the integration and peak values in the stacked spectrum. stacked spectrum only showing peak, neither peaks values nor integration values. please help me out.
Why does DMSO show quintet in 1H NMR?
Question
4 answers
- Jubyeong Chae
Hi guys,
I learned that dmso peak in 1H NMR caused by proton exchange.
So the peak at 2.5 ppm indicates dmso-d5 not d6
Also the dmso which have more exchanged proton like d4 or others can be shown but it is out of normal range.
Then, why the dmso-d5 represented quintet peaks?
Can anyone explain about this?
Thanks
Is it normal to get negative chemical shifts in ppm for H-NMR analysis?
Question
21 answers
- Chung Loong Yiin
I am getting negative chemical shifts in ppm for H-NMR analysis. Besides, most of the peaks are overlapping. Appreciate if anyone can answer my question.
Attached here with the H-NMR result.
Thank you.
How do you remove DMF without using a vacuum pump ?
Question
25 answers
- Bittu Chandra
DMF is a solvent with a very high boiling point. I want to know how to remove DMF without using a vacuum pump.
How can I remove triethylamine hydrochloride salt from the air and moisture sensitive reaction mixture?
Question
18 answers
- Sannapaneni Janardan
I am preparing silyl enol ether, during the course of reaction Et3N, HCl is formed as a by product. I want to remove that. Can you suggest a method to purify the compound from above dissolved by product after filtration?
What is the upper limit (distance) for considering Pi-Pi interactions, even though they are weak?
Question
7 answers
- Nagapradeep N.
I had cases where two 6-membered aromatic rings are slightly displaced with each other (I mean to say, they are not exactly face-to-face). The distance between their centroids is 4.2-4.4 Angstroms.
Would it be appropriate to say, "There are weak displaced pi-pi interactions are present in these cases."?
If possible, please suggest me some references.
Thanks in Advance.
When Journals Impact Factor for 2023 will release?
Discussion
80 replies
- Tariq Hussain
In general, Journals Impact Factor is released in the fourth week of June every year?
Is it inappropriate to use the LANL2DZ basis set in Gaussian calculations for a molecule containing only C, H, N, O elements?
Question
3 answers
- Tejaswi Ashok Hegde
I am using # opt freq=(raman,vcd) b3lyp/lanl2dz pop=(nbo,savenbo) scf=qc geom=connectivity for geometry optimization+other calculations of an organic molecule. I am getting the results using this function in a day or two. However, if I use 6-311+G(d,p), the same calculation runs for months and can still not achieve the results. Can please anyone answer whether I can stay with the outcome using lanl2dz, or should I go for 6-311....
Thank you
Related Publications
certificate HNMR
Data
- T. H. Al-Noor
Automated Chemical Mixture Analysis by Benchtop NMR: As easy as it gets Certeficate from ACS
Unambiguous 1 H-nmr Assignment of Phorbol Triacetate Using a Two-Dimensional NMR Technique
Article
- Gary T. Marshall
- Lee-Juian Lin
- A. Douglas Kinghorn
ChemInform Abstract: NMR STUDIES ON CYCLIC ARSENITES. PROTON NMR SPECTRAL ANALYSIS AND CONFORMATIONAL STUDIES OF 2-CHLORO-5-METHYL- AND 2-PHENYL-5-METHYL-1,3,2-OXATHIARSOLANE AND 2-CHLORO-5-METHYL-1,3,2-DITHIARSOLANE AND -1,3,2-DIOXARSOLANE
Article
- DAGFINN W. AKSNES
- MALVIN BJOROEY
Got a technical question?
Get high-quality answers from experts.
Top contributors to discussions in this field
Ludger Ernst
Imre Tóth
Anthony Foris
Frank T. Edelmann
Aref Wazwaz
Join ResearchGate to find the people and research you need to help your work
- 25+ million members
- 160+ million publication pages
- 2.3+ billion citations
or
- Join for free
- LoginEmail Tip: Most researchers use their institutional email address as their ResearchGate login
PasswordForgot password?
Keep me logged inor
Continue with Google
Welcome back! Please log in.
Email · HintTip: Most researchers use their institutional email address as their ResearchGate login
PasswordForgot password?
Keep me logged in
or
Continue with Google
No account? Sign up
- Badges
- Science topic
- Similar topics
- Chemistry
- Organic Chemistry