Running a 1H-decoupled 19F soln-state NMR experiment (1D) on 1,4 -difluorobenzene (0.1 ml in 0.5 ml CDCl3). It seems to require an extremely long acq. time. (truncating even at 8s acquisition time). Is this normal for partially fluorinated organics? Would increasing the recycle delay help? On a Bruker 300 MHz 1H instrument.
Hello,
your very slow transverse relaxation means you have perfect magnetic field homogeneity. If you do not want to wait until the FID has decayed completely just apply an exponential weighting function in order to avoid truncation artefacts. When you observe proton-decoupled 19F spectra it is not really harmful to increase the linewidth by this procedure. Keep up the good work.
Best regards,
Ludger
I forgot to ask you: why do you use such a huge amount of (symmetrical) 1,4-difluorobenzene to obtain a 1H-decoupled 19F spectrum? A hundredth of the quantity should still be plenty.
Thank you Dr. Ernst, I will try a larger LB. As for the quantity, that was a typing error, I actually used 0.1 ml in 0.5 ml CDCl3. Fixed it in the question now. Hope the solution works.
Best regards,
Rudy
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