tag:blogger.com,1999:blog-3300702123878659843.post5376549928910701322..comments2024-03-26T05:25:50.831-04:00Comments on University of Ottawa NMR Facility Blog: Virtual CouplingGlenn Faceyhttp://www.blogger.com/profile/05146575170575279335noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-3300702123878659843.post-50013403022471931632018-09-24T04:55:35.985-04:002018-09-24T04:55:35.985-04:00Thank you very much Glenn, of course a proper ackn...Thank you very much Glenn, of course a proper acknowledgement will be added.<br /><br />Thanks again<br />SaraSarahttps://www.blogger.com/profile/03781902483231461768noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-45302740066023442992018-09-21T08:14:49.126-04:002018-09-21T08:14:49.126-04:00Sara,
I'm glad you found the post helpful. Fe...Sara,<br />I'm glad you found the post helpful. Feel free to use the figures for your thesis with proper acknowledgement.<br />Glenn Glenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-43814035234909086252018-09-21T07:13:08.898-04:002018-09-21T07:13:08.898-04:00Hi Glenn, thank you for this simplified explanatio...Hi Glenn, thank you for this simplified explanation. Would it be ok if I use the two pictures in my PhD thesis?<br /><br />Best wishes,<br />SaraSarahttps://www.blogger.com/profile/03781902483231461768noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-82276755489146679212015-07-31T14:34:52.084-04:002015-07-31T14:34:52.084-04:00Dear Anonymous,
Thanks for your comments. I supp...Dear Anonymous,<br /><br />Thanks for your comments. I suppose you are right, but I do not think calling the difference between an ABX and an AA'X is a big deal when the only difference is 13C / 12C.<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-6316905792032714772015-07-31T12:21:33.606-04:002015-07-31T12:21:33.606-04:00Dr. Glenn
I am a big fan of your blog/web. The ex...Dr. Glenn<br /><br />I am a big fan of your blog/web. The example is excellent. If I understand well then 31P spectrum has only singlet since the phosphorous atoms are chemically equivalent in the major isotopomer, which is measured, thus they have identical shift and thus their coupling is non-observable, e.g. as between hydrogens in methane.<br /><br />The virtual coupling in 13C spectrum is also clear. However, when 13C spectrum is measured then each carbon signal comes from different 13C-isotopomer, in which the phosphorous are not chemically equivalent; they have probably very similar but not identical chemical shift in principal. Based on that, I thing, that the spin system should not be categorized as AA´X, which is reserved for chemically equivalent but magnetically nonequivalent nuclei, but ABX. I am right or wrong?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-51010862532206194272012-10-15T08:38:09.153-04:002012-10-15T08:38:09.153-04:00Anonymous,
The spectra in this post are not publi...Anonymous,<br /><br />The spectra in this post are not published. You can find a general discussion of virtual coupling here:<br /><br />N.E. Jacobsen, NME Spectroscopy Explained. Chapter 2, pp 69-71.<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-3595795808441877222012-10-14T17:01:13.539-04:002012-10-14T17:01:13.539-04:00Is it published somewhere?Is it published somewhere?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-49575132371656098722012-07-16T10:29:50.811-04:002012-07-16T10:29:50.811-04:00Anonymous,
Thank you for your comment. Yes, the ...Anonymous,<br /><br />Thank you for your comment. Yes, the 31P resonances are isochronous and therefore appear as a singlet in the 31P spectrum. The two P atoms are however coupled to one another.<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-1449201499093105542012-07-16T10:18:50.659-04:002012-07-16T10:18:50.659-04:00Thanks, that post helped me a lot. Just one questi...Thanks, that post helped me a lot. Just one question concerning the DPPE-molecule: if the two phosphorus atoms are strongly coupled to another, why is there just one singulet in the 31P-NMR? Is the chemical shift difference just too small?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-74458984551590928182011-08-15T21:01:18.634-04:002011-08-15T21:01:18.634-04:00Quite interesting - I'm glad you posted the gr...Quite interesting - I'm glad you posted the graphics to go with. This takes me back to my college days... :)<br />-DavidVirtual Receptionisthttp://www.smiledog.canoreply@blogger.com