![mestrenova peak annotation mestrenova peak annotation](https://media.springernature.com/m312/springer-static/image/art:10.1038%2Fnprot.2010.82/MediaObjects/41596_2010_Article_BFnprot201082_Fig3_HTML.jpg)
In order to keep the assignments propagation, follow the menu 'View/Tables/Assignments' to select what datasets you want to take into account (in the example below, we have selected the 1H and the 13C NMR datasets). To do that, select the atoms from the Table of molecules by following the menu 'View/Tables/Molecules'. you can also assign a 13C-NMR of the same molecule in the same document. We recommend you to assign your atoms to your multiplet boxes in order to transfer assignments through datasets. In the example below, we have assigned a -CH2 group, so a new window will be displayed to allow us to select which atom we want to assign, 18, 18', both (in blank) or even we can select any other annotation: 18a, 18b, cis/trans, ax/eq, etc:Īssign a multiplet by dragging the mouse to the 'multiplet box' (in this case the name of the multiplet is replaced with the atom number) or to the 'integral curve', as you can see in the picture below: You can also assign a region of the spectrum just by clicking, dragging and releasing the mouse over the desired region. Once the assignment has been made, you will get an atom number label on the chemical shift and hovering the mouse over the atom will highlight the applicable peak in the spectrum and hovering the mouse over the peak will highlight the corresponding atom on the molecular structure. This peak will now be assigned to the atom (which will turn to green). Once your desired peak is highlighted on the spectrum, click on it to assign it. Then follow the menu 'Analysis/Assignment' (or use the shortcut 'A').Ĭlick on an atom on the molecular structure (or a spectrum region) and then release the mouse and drag it to your desired peak. Open your NMR spectrum and load a molecule structure. Mnova provides a very simple interface to assign your molecule. The last remaining peak at 4.999 ppm must be proton 13 this is confirmed by COSY correlation with proton 12, triplet multiplicity based on splitting by proton 12, and integration of one proton.Note: Do not forget to have a look at our 1H NMR Automatic Assignments Tutorial We can assign proton 12 (3.564 ppm) based on its integration of 2H and its COSY correlation to proton 11. Proton 7’s peak at 6.163 ppm is split into a triplet by the two 8 protons, confirming the assignment.Īll that remains are protons 12 and 13. Once proton 8 has been assigned, we can easily assign proton 7 based on the remaining COSY correlation for proton 8. Therefore, we can assign proton 10 as 5.209 ppm and proton 11 as 3.754 ppm. To differentiate protons 10 and 11, take a look at our COSY table 3.754 ppm shows two COSY correlations, while 5.209 ppm only shows one. From this list, we can easily assign proton 8 as the peak at 2.068 ppm based on its integration of 2 protons. Based on the COSY, proton 9 couples protons at 2.068 ppm (2H), 3.754 ppm (1H), and 5.209 ppm (1H). Thymidine’s structure suggests that proton 9 should couple protons 8, 10, and 11. Now that proton 9 has been assigned, the fun really begins. The remaining protons are doublets, triplets, and multiplets that can be assigned by 2-dimensional COSY. The peak also integrates to 1 proton, supporting the assignment. The chemical shift of 11.256 ppm supports this assignment, as imide protons often show up far downfield. The only proton that should show up as a singlet is proton 6, as it has no neighboring protons that would split the peak (the nearest proton is 5 bonds away!). There is only one singlet in the ¹H-NMR spectrum. Therefore, the peak at 7.690 ppm must represent proton 4! The integration and chemical shift support the assignment, as proton 4 is the only aromatic proton in the structure. The long-range coupling constant observed for proton 3 (J=1.2 Hz, split into a doublet by proton 4) is reflected in the coupling constant for proton 4 (J=1.2 Hz, split into a quartet by proton 3). Protons that are coupled to each other should exhibit the same coupling constant. The peak is split into a doublet with a coupling constant of 1.2 Hz, reflecting the long-range coupling between protons 3 and 4, which also supports this assignment. The high field chemical shift supports this assignment. The only peak with an integration of 3 is the doublet at 1.770 ppm. Proton 3 is the only methyl group in the structure, and therefore must integrate to 3 protons.