1D ¹H PSYCHE Pure Shift NMR

The PSYCHE (Pure Shift Yielded by Chirp Excitation) NMR experiment largely removes J-Coupling from the Proton NMR signal. This can greatly simplify the spectra much like that of a decoupled 13C 1D you're familiar to acquiring. The experiment is actually acquired as a 2D and is later reconstructed back into the 1D free of J-coupling (don't worry sounds worse than it is..). The overall expt time is only 8 minutes. Below is a Quinine example:

Data Acquisition

• rpar psyche all - read in the parameter file for psyche expt
• wobb - tune the proton channel (the ones that turn not the sliders. ask if you need help)
• rga - sets the receiver gain (rg) which depends on the sample concentration (wait)
• zg - zero memory buffer and go (takes about 8 minutes)

Data Processing

• psyche - this breaks the 2D down into a 1D. The 1D is automatically saved in the (current expno + 1000) eg) 1+1000=1001.
• the window should automatically open to the 1D expt so now just process as you normally would
• note that the new expt (1001) etc can be treated just like any other normal 1D for offsite processing if you like.
• 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

Here is the aromatic region of Quinine just for further example:

Comments on Experiment

• The parameters used in this expt are the same as in the reference link above
• There can be small artifacts which can show down towards the baseline mostly so use discretion in interpreting results
• It is useful to record a standard 1D 1H as well and overlay the spectra as I've done above. eg) overlay 1001 with 2. see topspin manual regarding overlay.