Hello, I need to set up aquisition parameters for an echo solid sequence on bruker. In order to analyse deuteraed samples. Did any one has a paper or link for this sake. Thank you. asked Mar 03 '11 at 05:34 silvernmr |
you can look at Melinda Duer's textbook "Solid-state NMR spectroscopy" p. 113. Set your first echo delay to a minimum value that is necessary to cover the probe ringing ( usually 30-50us). The second tau delay is a few us smaller in order to catch the exact top of the echo. answered Mar 05 '11 at 11:33 liliya |
Thank you liliya for your ansewer. Otherwise I would like to check something. It's indicated in Duer's book p. 324, that in order to have symmetric ²H powder pattern," it's necessary that the center of the powder pattern be on the resonace" My first question, when she said symmetric pattern, she means that the intensity of each doublet is the same, or the distance between each doublet is centered at 0 Hz. My second question, in order to set the resonace on the center of the spectrum, should I set o1 at 0 Hz, and calibrate the center of the spectrum on 0 Hz (whatever the value of sr). Thank's a lot for your help answered Mar 06 '11 at 07:57 silvernmr Hi there, please use comments to post follow-ups - to keep the answer space less cluttered. It is also possible to edit the original question. - Evgeny Fadeev (Mar 06 '11 at 10:22) Yes. Set o1 to roughly 0ppm/ 0 Hz. Better yet, make sure the o1 is set to the center of the lineshape (powder pattern). This can be referenced as 0. For 2H in the solid state there is only a small amount of chemical shift to consider. 2H is dominated by quad interaction so set o1 to the center. - bernie o'hare (Mar 06 '11 at 11:56) |
Hello, Did you ever try to find out whether it is possible to get the Solid Echo in your spectrometer for protons. protons are simply Spin 1/2 nuclei where as deuterium is a quadrupolar nuclei. For protons, as I have seen while I was a post doctoral fellow at Max Planck Institute for Medical Research, Heidelberg, If one can see a Proton FID for solid with 90 degree pulse of reasonably short pulse width and High power, then by trying to aplly a 45 degree pulse before the FID decays completely, it is posible to see a refocussed signal. Once it is known how to see such asolid echo it should be possible to find the Solid Echo conditions for Quadreupolar deuterium nuclei. answered Mar 06 '11 at 10:01 |
Use the quadrupolar echo (spin 1 echo) sequence for 2H. 90(x) - tau - 90(y) - tau - Acq. You may use the pulse program "solidecho.av for a Bruker Avance spectrometer. Otherwise it would be fairly easy to write your own. For spin=1 nuclei (2H) this spin manipulation will result in a full refocusing of the magnetization (a full echo) where a typical Hahn echo will not. answered Mar 06 '11 at 11:47 bernie o'hare |