Producing Publication Quality PDFs of NMR Spectra Using TopSpin 3.5pl7



PDF files of NMR spectra can be produced using Bruker's TopSpin that look more professional and more clearly represent important information than other methods such as scanning printed spectra. It is possible to add structures and labels to the spectra to clearly identify compounds.

TopSpin is now available for free for academic users on Linux, Windows, and Mac OS X.
https://www.bruker.com/service/support-upgrades/software-downloads/nmr/free-topspin-processing/free-topspin-download.html
The system used for testing was TopSpin 3.5 pl 7 on Linux (Fedora Core 26 KDE Spin). The behavior is essentially identical on all operating systems.

Basic NMR Processing:
1. The chemical shift range should be calibrated to solvent residual signal (or TMS, if present) and use the value listed in Organometallics 2010, 29, 2176-2179.
Zoom in on the solvent residual peak, click the Process tab, click the Calib. Axis button, select the center of the solvent residual peak, and type in the appropriate value (7.26 PPM for CDCl3).


2. Use the peak picking tool to select peaks in the NMR spectrum. For each peak, there should only be as many values shown as the multiplicity of the peak. A quartet should show four values that can be used to calculate the coupling constant, a triplet three, and so on. Significant impurities and the solvent residual peak can optionally be selected, but small impurities close to the baseline should not be selected.
Click the Pick Peaks button under the Process tab to select peaks.


3. (Optional) Integrate peaks in the spectrum. If peaks are integrated, the bias and slope must be correctly set to achieve accurate integration. This is best accomplished by ensuring that the beginning and end of the integral are flat in an area of clean baseline. In the absence of a clean baseline near the peak of interest, a larger integral can be drawn to where there is clean baseline and cut using the cut integral tool


Produce High Quality PDFs of the Spectra

4. An appropriate spectral window should be selected. Use 0-10 PPM for 1H NMR and 0-200 PPM for 13C NMR. In cases where peaks fall outside this range such as many transition metal hydrides, a larger window may be necessary and a break in the axis may be reasonable.

5. Click the Publish tab and click the Plot Layout button.


6. Delete the Bruker symbol and the table Current Data Parameters if desired.

7. Select the appropriate page size by clicking the arrow to the right of Print and selecting page setup. The default page size is A4 (use outside North America), change to Letter for North America including all ACS journals.


Note: if an error message appears, you may need to make a selection for the printer first even though this will not be printed.


Select the spectrum in the plot layout window. Check the box for Labels under Peaks. For spectra with integrals, the default color of the peak labels is green. Change this to black by clicking the color box to the right of Peaks


9. Resize the spectrum so the red dotted line around the spectrum aligns with the gray dotted line representing the printable area of the page.

10. Click PDF and set the resolution to 600 dpi. 300 dpi may be insufficient to see details in the spectra.