Setup of 1D NOE spectra

• -General Remarks: The 1D NOE experiment can be a quick way to establish spatial information in small molecules without going through a lengthy 2D NOESY experiment if only few distances are needed .

The experiment involves selectively inverting one signal with low power and monitoring the intensity of the other signals.

• -SamplePreparation: Special care should be taken when preparing samples for NOE difference spectroscopy. The sample must not contain any solid material (filter!), and contain enough solvent for good shim. The presence of paramagnetic molecules will reduce or kill any observed NOE, so degassing the sample to remove oxygen will improve the results.

• -Lock and shim the sample as usual. Make sure spinning is turned off by clicking on SPIN ON-OFF button in the shim window of the BSMS display (the button has to show gray color).



• -take a regular 1D proton spectrum, process as usual. Zoom on the signal you want to irradiate, and enter the [utilities] submenu (left menu bar). Select [O2] from the left menu bar (not o1) and move the mouse cursor on the desired peak, then select the peak with the middle mouse button. select [return] to get back to the main menu.

• -Type new to create a new data set (for example experiment number 2 ). In the new data set, type rpar noe1d.hf all. Then type edc2 and define the 1D proton spectrum as second data set. Finally, type setnoe to copy the frequency defined in the previous step into the new file.



• -Adjust ns and d8: The default for d8 is 300 ms, larger values will let you see longer distances, but you will probably also loose more overall signal
• -type rga and zg



• -to do another spectrum with a different frequency: Type new to create a new file (new expno). Then switch back to the regular 1D spectrum (i.e. re 1 ) and define another frequency as described above. Finally switch back to the new file (re expno), and type setnoe, then zg.



• -Process as usual. The strongest peak in the spectrum should be your irradiated peak which should strictly speaking be phased negative, but apk won't do that. For small molecules, NOE peaks have opposite sign, for large molecules (viscous solutions) NOE's will have the same sign. You can integrate the irradiated signal to 100 (assuming it is one proton) and read the integrals of the other peaks directly in %.