First, you will need to create a standard file.  Create an empty file by typing edc.  Then type rpar, which brings up a big window.  Look for the nuclei of interest, eg., P31, Si29, B11, etc., and click on the choice, then click OK.  Then you must type getprosol to complete the standard file setup.

Once you have the standard file, the rest is similar to running a 1H or 13C experiment.  On 400, you will need to run atma.

Some nuclei have several options in the rpar window.  For example, P31CPD is P31 with proton decoupling, while P31 is without the decoupling.  You can run both and compare the spectra and look for the difference.

F19 only works on DPX300 (B622 Conte).  You can only select F19 (not F19CPD) in rpar window.  31P and 13C work on both DPX300 and Avance400 (LGRT room 075).  All other nuclei can only be done on Avance400.

Concentration

¹³C signal strength is only 1/6000 of ¹H. For ¹H experiments, any reasonable concentration will give you sufficient signal, but for ¹³C, usually the higher the concentration, the better. Our 400MHz and 500MHz instruments are equipped with Prodigy® cryoprobes which boost ¹³C signal-to-noise ratio significantly.

Signal strength is proportional to the molar concentration of your sample. Generally, if you have ~ 10 mM, you should be able to obtain a decent ¹³C spectrum within half an hour.

How to run ¹³C faster and obtain quantitative result

See these entries:

How to run quantitative 13C and 29Si NMR faster

Power of Cr(acac)3 – a T1 relaxation agent

Some Useful Commands

• go:  Similar to zg, except that the new data will not overwrite the existing data, but add on to the existing data.  This is helpful when you have finished a run but feel your existing data does not have sufficient signal-to-noise ratio and you wish to add more scans.
• lb: line broadening parameter.  its unit is Hz.  Change lb, then do efp, and you will vary the resolution and signal-to-noise ratio of the spectrum.  The default lb is 0.3-1 Hz.  Larger lb suppresses noise but broadens the peaks.  Properly tuning lb value is very helpful when your sample peaks are naturally broad.
• tr: transfer the data acquired so far to your file, so that you can examine the preliminary spectrum when the acquisition is still running in the background.  This is helpful when you setup a long experiment.  Do tr after 20-30 scans, and look at the data.  If you see nothing (not even the solvent peak), something is wrong.  You want to find the problem early on so that you don’t waste a whole night’s time.

Variations of ¹³C experiments

DEPT gives you stronger signal than regular ¹³C, but will not show signals from non-protonated carbons.

Although HMQC is a 2D experiment, it is at least as quick as regular ¹³C (likely quicker). It also tells you which carbon is bonded to which proton.

HSQC is very similar to HMQC but has higher resolution and CH₂ show up as negative peaks (like that in DEPT135), which further helps your signal assignment.

Many advanced NMR (both 1D and 2D) techniques are as easy to run as a regular 1H or 13C on our spectrometers.  Interestingly, some of them are even faster than the regular 13C.  This entry describes an easy-to-follow instruction on how to set up those experiments.

The following document is a more complete description of how to set up and process 2D NMR experiments.  Beginners should skip the discussions on how to change various experimental parameters.  The default parameter settings are very easy to setup and should already take you a long way.  Once you feel comfortable running 2D using the default parameters, you will find it easy to adjust many parameters.

2D NMR handout