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Cyclenoe Experiment Note:

CYCLENOE¡ªCycled NOE Difference Experiment
The cyclenoe macro sets up parameters for a cycled NOE difference experiment.

CYCLENOE requires that the observe channel be equipped with direct synthesis rf and a
linear amplifier.INOVA, UNITY Plus and VNMRS are OK. This experiment does not apply to MERCURY-VX, MERCURY, or
GEMINI 2000 systems; Use the NOEDIF experiment instead.

Parameters
pw is a 90¡ã excitation pulse (at power tpwr).

intsub='y' sets internal subtraction of data acquired by on-resonance and offresonance selective excitation on alternate scans. intsub='n' makes data acquired by on-resonance and off-resonance selective excitation to be stored separately; only 1D with satfrq is collected. The result spectrum is with the subtraction. set a lb=5.


satfrq is the frequency of selective saturation (on-resonance).-- The peak has NOE with others to be observed.
control is the off-resonance selective saturation frequency --- Backgroud (an inactive parameter if intsub='n'). If control is inactive, off-resonance spectra is not collected. cycle='y' does on-resonance saturation using frequency cycling around the frequency satfrq given by spacing and pattern; cycle='n' does off-resonance saturation at control.


spacing is the spacing, in Hz, of the multiplet.
pattern is the pattern type (1 for singlet, 2 for doublet, etc.). Fit the desired pattern to some value, even if some frequencies do not fall on NMR lines

tau is the time spent on a single irradiation point during cycling.
satpwr is the power of selective irradiation (typical values are at lowest power).
sattime is the total length of irradiation at frequency satfrq.
mix is the mixing time.
sspul='y' does trim(x)¨Ctrim(y) before d1.
nt is a multiple of 16 if intsub='n', nt is a multiple of 32 if intsub='y'.


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CYCLENOE does alternate scan subtraction of two FIDs in which the saturation frequency is moved on-resonance and off-resonance (for intsub='n'). Separate data tables are stored for intsub='n'. Power may be reduced from ordinary NOE experiments because
the irradiation can be cycled (cycle='y') through the lines of a multiplet.


1. One way to set up satfrq is by entering dn='H1' and using sd the same as in homodecoupling. Then enter satfrq=dof and dn='C13'.


2. Adjust proper satpwr by setting nt=1 and arraying satpwr from 3 to ¨C16 on UNITYINOVA and UNITYplus systems, and from 3 to 0 on UNITY and VXR-S systems. Enter proper values for pattern and spacing. tau is typically a few hundred milliseconds. sattime is usually several seconds.


3. Acquire the data and select the power necessary for 50 to 75% saturation. Then set nt to a large number (several hundred).

4. Set the control frequency as near as possible to satfrq to make the control and satfrq conditions as close as possible. The control frequency should be ¡°in the noise,¡± not on top of a multiplet. Several protons may be done simultaneously for one control frequency.
5. Enter appropriate frequencies for patterns and spacings.
6. Set array='(satfrq,pattern,spacing)'. This performs the proper number of experiments.
7. Run nonspin and temperature-regulated. A large number of transients result in better subtraction.

 

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