tag:blogger.com,1999:blog-3300702123878659843.post2869847632318560442..comments2024-03-26T05:25:50.831-04:00Comments on University of Ottawa NMR Facility Blog: Proton NMR Assignment Tools - The D2O ShakeGlenn Faceyhttp://www.blogger.com/profile/05146575170575279335noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-3300702123878659843.post-61973393168056912512024-03-02T16:59:54.427-05:002024-03-02T16:59:54.427-05:00anonymous,
Yes, the D2O will exchange with NH prot...anonymous,<br />Yes, the D2O will exchange with NH protons albeit more slowly than with OH protons. <br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-31663882199808674382024-03-02T16:56:36.540-05:002024-03-02T16:56:36.540-05:00Will this happen with NH amide protons? Thank you ...Will this happen with NH amide protons? Thank you kindly!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-42739098183819885182020-07-27T08:47:40.715-04:002020-07-27T08:47:40.715-04:00Anonymous,
One drop of D2O is sufficient for a typ...Anonymous,<br />One drop of D2O is sufficient for a typical NMR sample with 1 - 20 mg of sample in ~0.6 mL of solution.<br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-70230033747467680052020-07-24T05:57:01.757-04:002020-07-24T05:57:01.757-04:00What are typical relative amounts of D2O that you ...What are typical relative amounts of D2O that you need to use to perform a D2O shake?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-70542651165441399412020-02-28T10:06:27.193-05:002020-02-28T10:06:27.193-05:00RITMAX,
No. Almost always, 1H NMR spectra are reco...RITMAX,<br />No. Almost always, 1H NMR spectra are recorded on samples in deuterated solvents. The sample used for this post was dissolved in deuterated chloroform.<br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-72433593336269211442020-02-27T22:35:23.041-05:002020-02-27T22:35:23.041-05:00Does this imply that deuterated solvents are not u...Does this imply that deuterated solvents are not used to run the normal proton NMR spectra?RITMAXhttps://www.blogger.com/profile/03429478502284585108noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-40496289578924726052019-03-16T16:32:43.577-04:002019-03-16T16:32:43.577-04:00thank you somuchthank you somuchAnonymoushttps://www.blogger.com/profile/07383973410714885084noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-13589590110793119642018-04-16T11:25:50.699-04:002018-04-16T11:25:50.699-04:00Unknown,
That is a good question. I guess many us...Unknown,<br />That is a good question. I guess many users do not want to get their samples wet as it makes them more difficult to recover or perhaps they do not want to deuterate the exchangeable protons. Many people identify exchangeable protons by running a 1H-13C HSQC. <br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-58399624196955977442018-04-16T09:17:49.923-04:002018-04-16T09:17:49.923-04:00Why this method is not frequently used these days?...Why this method is not frequently used these days?Anonymoushttps://www.blogger.com/profile/10812907108137718181noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-12216865738232139552017-03-21T08:29:43.966-04:002017-03-21T08:29:43.966-04:00Anonymous,
The residual -COOH or -OH protons after...Anonymous,<br />The residual -COOH or -OH protons after addition of D2O to the sample often undergo fast exchange with any water protons present in the sample. The single resonance as a result of fast exchange is between the water resonance and the -COOH or -OH resonance. Its precise position depends on the relative amounts of water and -COOH or -OH. For example, in the case of CDCl3 where residual water appears at ~1.6 ppm and -COOH at ~13 ppm, the exchange peak could appear anywhere between 1.6 ppm and 13 ppm depending on the relative amounts of water and -COOH in the sample. <br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-6719495236517450572017-03-18T10:02:42.695-04:002017-03-18T10:02:42.695-04:00The acidic protons (-OH, COOH)after being exchange...The acidic protons (-OH, COOH)after being exchanged, where it will appear in the NMR Spectra in different deuterated solvents such as CDCl3, DMSO-D6 and mixture of DMSO-D6+D2O (two different water residual signals) ?????<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-67273436954384998652017-03-06T11:02:21.821-05:002017-03-06T11:02:21.821-05:00Thank you.Thank you.Anonymoushttps://www.blogger.com/profile/02085192293470270078noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-31475095650816525252017-03-06T10:01:20.424-05:002017-03-06T10:01:20.424-05:00Anonymous,
Despite the intramolecular hydrogen bon...Anonymous,<br />Despite the intramolecular hydrogen bonding in 2-acetylphenol, I would be surprised if the phenolic proton would not exchange with D2O albeit at a slower rate than comparable phenolic protons in the absence of hydrogen bonding. These types of protons can usually be identified by their characteristically high chemical shift values.<br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-26773469337374267312017-03-05T15:58:22.646-05:002017-03-05T15:58:22.646-05:00This is very clear for exgeable protons. But how t...This is very clear for exgeable protons. But how to identify protons involved in intra-molecular H-bonds, like in 2-acetylphenol??? these protons wouldn't be exchangeable: their chemical shift is not altered by the concentration modification and the D2O shake test inefficient.Anonymoushttps://www.blogger.com/profile/02085192293470270078noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-65565415218102183712013-05-09T05:13:17.807-04:002013-05-09T05:13:17.807-04:00Wow my book makes it sound more complicated than i...Wow my book makes it sound more complicated than it really is. Good explanation. Thanks!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-5786044098007761222012-12-06T00:38:18.310-05:002012-12-06T00:38:18.310-05:00thanks for valuable information.thanks for valuable information.Anonymousnoreply@blogger.com