tag:blogger.com,1999:blog-3300702123878659843.post151222082603028130..comments2024-03-26T05:25:50.831-04:00Comments on University of Ottawa NMR Facility Blog: Hahn Echo for 11B Background Suppression in SolidsGlenn Faceyhttp://www.blogger.com/profile/05146575170575279335noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-3300702123878659843.post-78824589917469630802013-01-03T10:30:17.579-05:002013-01-03T10:30:17.579-05:00DX.
I reccomend Melinda Duer's book "Sol...DX.<br /><br />I reccomend Melinda Duer's book "Solid-State NMR Spectroscopy" chapter 2 section 6.<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-4251148247861174472013-01-03T09:59:44.046-05:002013-01-03T09:59:44.046-05:00Hi Glenn,
MAS at 15k at RT. A pure amorphous soli...Hi Glenn,<br /><br />MAS at 15k at RT. A pure amorphous solid containing a para-substituted benzene group. Echo delays varied by multiples of rotor period.<br /><br />Can you point me to some basic readings of NMR echos?<br /><br />Thanks a lot, and Happy New Year!<br /><br />DXAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-7483471877214015382013-01-03T09:23:26.857-05:002013-01-03T09:23:26.857-05:00Anonymous:
Thank you for your comment. The echo ...Anonymous:<br /><br />Thank you for your comment. The echo spectra would not be quantitative (in comparison to a Bloch decay spectrum) if the T2's are of the same order as the echo delays and different for the two types of protons. Were you using MAS?<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-14228738000806688082012-12-27T14:34:22.275-05:002012-12-27T14:34:22.275-05:00Hi Glenn,
Can you comment on why the echo spectra...Hi Glenn,<br /><br />Can you comment on why the echo spectra are not quantitative(I think)? I once had a pure sample which gives proton echo spectra with different aromatic/aliphatic ratio when the delays are varied.<br /><br />Thanks.<br />DXAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-41796212141301511702012-11-16T11:03:12.898-05:002012-11-16T11:03:12.898-05:00N.T.
Thank you for your question. Using a Hahn e...N.T.<br /><br />Thank you for your question. Using a Hahn echo or solid echo to suppress background signals for spin I = 1/2 nuclei should also work well. I have done this for wideline 1H observation in solids.<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-50956622181285405152012-11-16T10:35:10.690-05:002012-11-16T10:35:10.690-05:00Hi,
What about non-quadrupolar nuclei (I=1/2) whe...Hi,<br /><br />What about non-quadrupolar nuclei (I=1/2) where dipolar coupling is only important? Could you give feedback or provide a reference?<br /><br />Thanks,<br /><br />N.T.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-74790964221883586092012-11-02T09:10:02.664-04:002012-11-02T09:10:02.664-04:00Neil,
The answer to you question is not simple. ...Neil,<br /><br />The answer to you question is not simple. In the case where the quadrupolar coupling is much weaker than the rf, one should get a maximum in the echo for the central transition when the second pulse in the echo sequence is either 90 or 180 degrees however, the echoes from both the central and satallite transitions will be observed when the second pulse is less than or equal to 90 degrees. The situation is not as simple when the quadrupolar coupling is of the same order as the rf. A good reference is:<br /><br />p. Man, Phys. Rev B. vol 52, p.9418 (1995).<br /><br />I hope this helps.<br /><br />GlennGlenn Faceyhttps://www.blogger.com/profile/05146575170575279335noreply@blogger.comtag:blogger.com,1999:blog-3300702123878659843.post-60084688732721414662012-10-27T22:02:06.475-04:002012-10-27T22:02:06.475-04:00Hi,
Thanks for your helpful post. What is the dif...Hi,<br /><br />Thanks for your helpful post. What is the difference between solid echo and hahn-echo and how do you know when to use which? I know the difference comes from the second pulse being 180 (hahn-echo) versus 90 (solid echo). What is the advantage of using one over the other, but I don't see the advantage of using one versus the other.<br /><br />Thanks,<br />Neil TannerAnonymousnoreply@blogger.com