[Question from NMRWiki Q&A forum] Simple 1H-NMR Assignment Query
Simple 1H-NMR Assignment Query
Hi guys, sorry to be really cheeky and sign up simply to ask for help, but here goes.
I've done a simple Grignard addition of isopropyl magnesium bromide to 3-methoxy benzaldehyde and I'm just assigning the peaks, but I've come up stumped on one issue.
Concerning the isopropyl -CH(CH3)2 proton (at approximately d=1.95p.p.m.), it's observed as a septet, but the integration is 2.14 and I'm stuck as to why. This Grignard addition should occur non-preferentially at either the Re-/Si- face of the aldehyde, so can it be explained by some form of entiomeric...
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In the case of oxidized plastocyanin from Synechocystis sp. PCC6803, an NMR approach based on classical two and three dimensional experiments for sequential assignment leaves unobserved 14 out of 98 amino acids. A protocol which simply makes use of tailored versions of 2D HSQC and 3D CBCA(CO)NH and CBCANH leads to the...
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[NMR paper] Simple techniques for the quantification of protein secondary structure by 1H NMR spe
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http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Simple techniques for the quantification of protein secondary structure by 1H NMR spectroscopy.
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nmrlearner
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[NMR software blog] Trigonometry for Dummies
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http://3.bp.blogspot.com/_ROkYShLRKqA/St8YrbCAlXI/AAAAAAAAASc/K1laXoqDekI/s400/tfd1.png
This is a doublet of doublets. If you move one doublet towards the other, for example by increasing the smaller J, the central peaks will coalesce into a single peak of double intensity (the algebraic sum of the central peaks).
http://3.bp.blogspot.com/_ROkYShLRKqA/St8Yrs_DvMI/AAAAAAAAASk/joz48TUIqU0/s400/tfd2.png
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[NMR software blog] NMR for Dummies
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Here is where the real fun begins. I was not joking with my previous post. You can really do these things at home. The simple instructions are available on another site, and they are illustrated. After completing the tutorial (it takes 5 minutes in total) a working application will remain in your hard disc, and you will be free to apply the same treatment to your own spectra.
iNMR has always been available as a free download (since 2005). Access is unlimited and the program never expires. Other specialized simulation modules are included to cover most of the needs of an...
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