2D NOESY Experiment

This two-dimensional phase-sensitive NOESY experiment measures the distance-dependent nuclear Overhauser effect between protons separated by less than 5A.  Before setting up the NOESY experiment, see Acquiring and Processing 2D Experiments.

N.B. - For molecules (in organic solvents) with MW from 1000 - 3000, the ROESY experiment may be more appropriate, as the NOEs for molecules of this size may be null, or zero.

See the Varian Guide to NMR Experiments for a complete description of this experiment.

Setting up the experiment: 

  1. Copy the experiment in which the 1H reference spectrum was collected to the present experiment (i.e. mf(1,3) if you're in 
exp3 and a 1H spectrum was collected in Exp1).
  2. Type noesy.
  3. Type dg. Adjust the parameters in bold listed below for the standard NOESY:
  4. ss=2
    		 
    sfrq=already set
    		 
    tpwr = listed at console
    		 
    tn=H1
    		 
    pw = 1H 90° pulse width listed at console
    		 
    at = set by spectrometer
    		 
    d1* = 1H relaxation delay (1-2 * 1H T1)
    		 
    np=2048
    		 
    presat='n'
    		 
    sw = sw from 1H reference spectrum
    		 
    mix=0.2 to 1.2 (see below)
    		 
    d2=0
    		 
    nt* = multiple of 8
    		 
    tof = tof from 1H reference spectrum
    		 
    sw1 = sw from 1H reference spectrm
    		 
    ct = set by computer
    		 
    ni* = multiple of 64
    		 
    dm='n'
    		 
    
            		
        
          
    dp='y'
    
            		
      
    
      
    
        
          
    
            		
        
          
    hs='n'
    
            		
      
    
      
    
        
          
    
            		
        
          
    sspul='n'
    
            		
      
    
      
    
        
          
    
            		
        
          
    phase=1,2
    
            		
      
    
      
    
        
          
    *Change ni, nt, and d1 to suit your scheduled time (see below).
    
            		
        
          
    temp=25 su -- to set variable temperature to 25 degrees
    
            		
      
    
    
    
  
    5. 
  
  5. ***TURN OFF SPINNER***  
    
  
    6. 
  
  6. 

    au to start acquisition
    
  
    7. 



 


 


 


 


The vertical (non-acquisition) resolution equals sw1/2ni.


Typical values are listed below for sw1=4400 and mix=0.5:








d1

ni

nt

time (hr:min)
vert. res (no 0 fill)
 

d1

ni

nt

time (hr:min) vert. res (no 0 fill)





1.5

128

8


1:18

17.2 Hz		
 


1.5

128

64


10:17

17.2 Hz		





1.5

256

8


2:37

8.6 Hz		 


1.5


256

64

20:42


    8.6 Hz




1.5

512

8


5:15

4.3 Hz		 


1.5


512

64

41:56


    4.3 Hz




1.5

128

16


2:34

17.2 Hz		
 


2.25

128

8


1:42

    17.2 Hz		





1.5

256

16


5:11

8.6 Hz		 


2.25


256

8

3:30


    8.6 Hz




1.5

512

16


10:29

4.3 Hz		
 


2.25

512

8


6:59

    4.3 Hz





Processing, Displaying, and Plotting:




Process using the procedure for Processing a 2D Phase-Sensitive
Experiment.  Plot All Contours.  The NOESY spectrum
may be symmeterized by typing foldt.



Setting mix, the NOE mixing time parameter


mix is the time period (in seconds) during which magnetization
is transferred from one 1H to another 1H.
 mix must be long enough to transfer magnetization between
spins to "build up" the NOESY cross peak intensity between
the two spins.  If mix is too long though, the magnetization
transferred to the second 1H will "diffuse"
to additional spins, decreasing the NOESY cross-peak intensity
between the two spins and creating new cross peaks between spins
that are farther apart than 5A.  Typical values for
mix range from 0.2 to 1.2 seconds depending upon the sample's
molecular weight; 0.8 is generally a good starting point. 



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Last updated: April 1st, 1998

URL: http://nmr.chem.indiana.edu/NMRguide/2dexpt/noesy.html

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The Trustees of Indiana University