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Hello, My 1H MAS NMR spectrum comes out with the right spinning side band pointing up and the left one pointing down. Does anyone know what that means? I am running NMR on a hydroxylated metal oxide material. I use 3us pulse width, 5 sec acquisition time, and my sweep width is 100kHz. Also, I am using a 600 MHz Varian magnet, 5mm rotor, and spinning at 10kHz. Thank you very much |
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Are these really sidebands, is there only one pair? If so, slow vrot to see if you can get a better sideband manifold and see if these additional sideband pairs also behave in this way. This sounds strange, maybe this is not a true sideband. Make sure by changing vrot. I am pretty sure that these are side bands because 1) they are symmetrically located around the main peak and 2)they are ~20 kHz apart, matching the ~10 kHz spinning speed. I will try my experiment at a slower spinning speed and see what happens. - NMRUser61581 (Jan 03 '11 at 10:04) |
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It would be great if you could post a picture of the spectrum, that might help us identify what's going on. I will say that sometimes sidebands can invert if you're left-shifting your spectrum too much (this adds phase across frequency space in the fourier transform). This is usually not perfectly 180 degrees different though. What are your processing parameters? |
Hello, you can post a picture too, if you like. - Evgeny Fadeev (Dec 16 '10 at 10:19)