Comparing Parameter Settings in Cyclenoe

Cyclenoe is one of the trickiest 1D experiments to set up in order to get a clean spectrum. Besides spectrometer and probe stability, the recycle delay (d1) and saturation time (sattime) settings, among others, may have a big impact on how clean the difference spectrum is. The following compares results from several cyclenoe experiments on the same compound collected with different d1 and sattime values within a 2 hour span. The experiments took from 10 to 25 mins each. Except for the d1 and sattime differences, all other parameters are kept the same:

Longest T1 of the Strychnine sample is measured

T1_max ~ 2.9 sec. See the cyclenoe setup page for details of the T1 measurement.

NOE difference spectra from cyclenoe

The experiment done with d1=16 (~5*T1_max) sattime=8 (~3*T1_max) gives the cleanest spectrum for this sample, excluding other unknown factors.

1H spectrum 1H spectrum
  • d1=8
  • sattime=8
d1=8 sat=8
  • d1=8
  • sattime=4
d1=8 sat=4
  • d1=2
  • sattime=8
d1=2 sat=8
  • d1=16
  • sattime=8
d1=16 sat=8
  • d1=8
  • sattime=16
d1=8 sat=16

H. Zhou updated Oct 2010