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1D NOE difference spectroscopy

Nuclear Overhauser Effect
uses multiple frequencies with cw irraditation

    new expno
  1. new
    1. start a new experiment
    2. update the expno
    3. choose: 1H_noemul

  2. standard 1H NMR
    Change the pulse program to zg
    • (type: pulprog zg)
    Acquire a spectrum as usual:
    • sign the log-book
    • lock
    • shim
    • rga
    • zg
    • proc
    Tailor the standard parameters:
    • td, sw, sfo1 (and optional/optimal: p1, d1)

  3. frequency list #1 (off-resonance irradiation)
    1. zoom in on your off-resonance region of interest
    2. click on the freqlist icon icon or type: .freqlist
    3. choose an FQ2List, giving it yourname.1
      freqlist icon
    4. use the mouse to define a list of frequencies
      (choose ~6 different nearby values)
      left-click to define
      right-click to "Save & Quit" the frequency list
      freqlist icon
    5. yes

  4. frequency list #2 (on-resonance irradiation)
    1. zoom in on your peak of interest
    2. click on the freqlist icon icon or type: .freqlist
    3. choose an FQ2List, giving it yourname.2
    4. use the mouse to define a list of on-resonance frequencies
      freqlist icon
      (choose ~6 different nearby values)
      left-click to define
      right-click to "Save & Quit" the frequency list
    5. create as many frequency lists as desired, each time incrementing the extenstion number (yourname.3, etc.)
      If you create >3 lists, it is recommended to run a second off-resonance list at the end

  5. Increase the expno and update parameters
    1. to go to the next experiment number, type: iexpno
    2. change the pulse program in the AcquPars, type: pulprog noemul
    3. test the frequency list, type: fq2list yourname.1
    4. use ns 8, ds 2, l4 50 (loop for multiple irradiation), d20 0.05 sec (irradiation time at each frequency)
    5. check that the experimental time is ~2 minutes, type: expt
    6. type: zg
    7. check that the spectrum matches the previous experiment number (off-resonance irradiation)


  6. Increase the expno again and check the saturation
    1. type: iexpno
    2. to test the on-resonance irradiation, type: fq2list yourname.2
    3. check that the experimental time is ~2 minutes, type: expt
    4. type: zg
    5. compare the current spectrum with the previous expno to check that the peak of interest is gone (saturated due to on-resonance irradiation)

      NOTE: the default parameter set is for 2.5 seconds of NOE irradiation.
      It uses 50 msec at each frequency in the current frequency list - 50 times.

  7. Acquire
    type: noemul
    • base name of all frequency lists: name space (NOTE: noextension!)
    • number of frequency lists: 2space (# of name.n's created)
    • number of cycles through each list: 50 space (same number as l4)
    • number of average cycles: 4 space (NOTE: 32 shots = ns 8 * 4 cycles)

    NOTE: if the experimental time in step 5 was 2 minutes, and you have two lists, and you are running 4 cycles, then the total experimental time should be ~16 minutes

  8. Process & plot
    1. Process the first experiment as usual

    2. To process the second experiment with the exact same parameters:
      type: "multiefp"
      A window will ask for the current experiment number, click: enter
      A second window will ask how many experiments to process,
      space if you had 2 frequency lists, then choose 2
      space interactive multiefp window

    3. create a difference spectrum in multiple display mode
      • Enter multiple display mode .md
      • Add the on-resonance experiment, for example type: re 2
      • Highlight the green triangle to get the difference spectrum -
        you can use the floppy disk icon to save the difference spectrum .md tool bar

    4. To get a screen shot, type: prnt


  9. Report problems and bugs to Yael or Shifi - 3748