It is possible to run NMR experiments with non-deuterated solvents. It will have to be run in an unlocked state. Follow these steps:

1. rsh shims.best
2. In bsmsdisp window, go to LOCK tab, if the LOCK button is either red or green, click it so that it is white.
3. Click the SWEEP button so that it is white.
4. rga
5. (optional) shim on the FID. Type gs (similar to zg but without accumulating data, used for real time adjustment of various parameters), then adjust z and z2 in bsmsdisp window  to make the FID as long and thick as possible.
6. zg. If step 5 is not done, the spectrum collected will be of lower resolution as shim is not optimized.

Graphic outputs are advantageous over printouts in many respects. They are easier to store and file.  They have higher resolution and are easier to incorporate into papers or reports.

There are two ways to generate graphic outputs in Topspin:

1. In xwp, choose Print and select Print to File.  It will generate a .ps file which is of high resolution and can be easily processed in standard graphic software such as Adobe Illustrator.

2. In main menu, click File and select Export.  you will need to add an extension name to specify the graphic format.  Popular choices are .png and .jpg.  The resolution of these files is not as high as the .ps file generated in xwp.

These files are saved in your home folder (/home/…) rather than the Bruker data file folder (/opt/topspin…).  You will need to delete those files in you home folder frequently since they reside on a small disc partition, which gets full quickly.

Assuming you are dealing with two peaks, each from a different molecule (A and B), and you want to figure out their molar ratio and weight ratio.

First, measure the signal area of the two peaks, area(A) and area(B).

Second, count number of protons (or other nuclei in question) contributing to the peak, N(A) and N(B).

Third, find out the molecular weight of the molecules, MW(A) and MW(B).

The molar ratio is: 

mol(A)/mol(B) = [area(A)/N(A)]/[area(B)/N(B)]

The weight ratio is:

wt(A)/wt(B) = [mol(A) * mw(A)]/[mol(B) * mw(B)]

You can also calculate the concentration of one sample using another sample as a reference with known structure and concentration.  First, run NMR for the two samples.  They will have to be run with the same NMR techniques, same parameters, and with the same rg (receiver gain).  Second, integrate the peaks in the reference sample.  Third, integrate the peaks in the sample in which you want to find the concentration, then right click on the integration and select “Use last scale for calibration”.  Then you will be able to find the area ratio between the two samples.  This ratio, normalized by number of scans, can be used to further determine mole ratio, weight ratio, or concentration ratio.

Same principles can be applied when calculating moles and weights of interested molecules in solid-state NMR. For two samples A and B, the weight ratio for the molecules contributing to the peaks of interest is:

wt(A)/wt(B) ={ [area(A)*mw(A)]/[N(A)*NS(A)] } / { [area(B)*mw(B)]/[(N(B)*NS(B)] }

On a DEPT-135 Spectrum, any carbons that are not bonded to protons will not have peaks.  Since solvent carbons are bonded to deuterium – not protons – those carbons will not have peaks either.

The protonated impurity in the solvent will have a small carbon peak on the DEPT135 spectra, but as a singlet rather than a multiplet.  And that peak will have a slightly different chemical shift than its deuterated counterpart due to isotope effect.

The 13C chemical shifts of CDCl3 and CHCl3 are different.  This is called the isotope effect, arising from the difference in mass for 1H and 2H.  So when you reference your spectrum using solvent 13C signals, be sure to use the chemical shift value of the deuterated version of the molecule.

This link gives a good overview of this effect.

Sample spinning helps to remove X and Y shimming imperfections.  This will improve resolution for routine 1D 1H and 13C spectra.  For any other advanced experiments, spinning is not recommended as it might introduce artifacts into your spectra.

When running routine 1H or 13C spectra, if the sample does not spin, you might want to touch up X and Y shims in addition to Z and Z2.  Please note that topshim for 400 only corrects Z – Z4 shims.  So, after topshim, if the lock still seems noisy, touch up X and Y.  Higher order transverse shims (XZ, YZ, XY etc) usually do not markedly affect resolution.

If your samples do not have deuterated solvent, you should run your spectra in unlocked state.  In bsmsdisp, uncheck lock (make the button white), then go to “lock” tab and uncheck “sweep on-off” button.

The spectra will not be of the highest resolution because you will not be able to shim using the 2H lock signal.  If resolution is a concern to you, you can shim by watching the FID.

Cl and Br have huge quadrupolar moments and their effect to other nuclei in the neighborhood can be considered non-existent.

The effect of 14N is dependent on its electron environment.  3-coordinated 14N has a large asymmetry in electron structure and thus the quadrupolar coupling is large, thus usually has negligible effect to neighboring nuclei.  4-coordinated 14N is more electronically symmetric and has a smaller quadrupolar coupling, therefore can split neighboring nuclei.  In this case, the neighboring 13C will be split into a triplet with intensity ratio of 1:1:1.  The splitting distance gives you the J-coupling constant between the nucleus of interest and the 14N.

2H has a fairly small quadrupolar coupling so it almost always split neighboring 13C to a 1:1:1 triplet.  Those who have run 13C spectra of samples with CDCl3 must be quite familiar with those triplets!

If you use acetone-d6 or dmso-d6 as solvent, the solvent peak on 13C spectra is not triplet but a septulet.  Do you know why and can you predict the intensity ratio of the 7 peaks?

31P and 19F have a spin of 1/2 and will always split neighboring nuclei to a 1:1 doublet.  If multiple 19F are present in the neighborhood, your 13C peaks will have a more complex splitting.