1D ¹H selective NOE

The selective 1D NOE expt can save considerable time compared to the 2D version. A peak of interest is manually selected and its neighbors/atoms which are in close proximity show an NOE peak enhancement. Take for example the methyl peak in ethyl benzoate:

Note the peak selected in red is manually phased down while the rest of the peaks should be pointing up (usually). APK will not work here. Also, the peak in red is clipped because the NOE peaks are only on the order of a 3-8 percent relative to the selected.

be sure to lock, shim and wobb before starting the data acquisition
1st acquire a normal 1D 1H and then run the selnoe expts
must use 500s as 400 can't handle such expts!


• rpar h1.bbo all - read in the parameter file for proton expt and run as normal..
• o1 - write this number down eg)2753
• now hover cursor over peak of interest in normal 1D 1H and note the frequency in Hz! some times you need to activate the cursor display by r.cl. in window and display cursor information. Maybe begin to make a table of values if mutiple peaks will be selected. Take the difference between peak of interest and O1. eg) 4250-2753. This is the value 'spoffs1' which needs to be plugged into the expt. See below diagram for more illustration..
• edc - now create new expt 2 etc. (can use iexpno as well)
• rpar selnoe.bbo all - read parameters for selective NOE
• spoffs1 - enter value of frequency difference determined above (peak1 - o1)
• rga - sets the receiver gain (rg) which depends on the sample concentration (wait)
• zg - zero memory buffer and go

Data Processing, see Chp 11 of Topspin 1.3 manual (page 143)
• tr - trace command allows to store current FID which can then be processed while the data is still acquiring
• efp - exponential line broadening, Fourier transform and phase (with current params in 'edp')
• lb - change the line broadening weight and run efp again if you like
• be sure to manually phase main peak down and have the little peaks pointing up..

Peak selection illustration



Comments on Experiment

• The NOE experiment here (transient NOE) is fundamentally different than the conventional 2D NOE or 1D difference NOE expt (Steady State)
• It is possible to calibrate distances, but only thru build up curves as seen in Fig.5e
• consequently if only a single expt is used then it is best to designate peaks as either strong, medium or weak. Using percents aren't too meaningful here.
• currently i've set the NOE mix time (D8) to 2s. please feel free to change as you like.
• Please be aware that these expts are so sensitive that they pick up on relay type transfers which can flip the sign of NOE. See Fig.13

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