Assignments Table

Once you have finished with the assignment, you can visualize the assignment list by following the menu 'View/Tables/Assignments'. From here, you can edit any entry by double clicking on it and overwriting the new value. Hovering the mouse over any cell of the table, will highlight the signals on the spectrum and the atom on the molecular structure.

Bear in mind that you can carry out the peak assignment directly from this table by typing the applicable chemical shift in the edit box.

If you use the Assignment table to type directly the assignment of a CH2 you would need add the prime marks if you want to assign only any of the two protons. If you do not type the prime marks, the assignment will be applied to both protons.

For example; typing this in a CH2 row: 3.0, 3.5',3.7'' means that 3.0 ppm is the chemical shift of both protons and in addition the H' has a signal at 3.5 ppm, whilst H'' appears also at 3.7 ppm. The assignments table will automatically refresh showing something like this (after having typed: 3.0, 3.5',3.7''):

Double click on the applicable 'atom cell' to change the  label of a -CH2 group. You can also change the atom number by double clicking on the applicable atom cell:

You can do ambiguous assignments in a -CH2, just by typing both values in the chemical shift cell (both chemical shifts are assigned to both protons)

If you want to do unambiguous assignments (one chemical shift belongs to proton a and the other to proton b), you will need to assign each proton:

Type the value of the coupling followed by the atom number involved, to include coupling constants in the assignment table. If you want to add an ambiguous assignment, type the coupling constant value and press the 'enter key' (a question mark will be added between brackets):

The couplings will be added by pairs, in the same way as in the correlations columns, i.e., when the J(2-3) is created, the coupling J(3-2) is also automatically added, with the same value.

Click on the "Get Js" button to read the J couplings of the multiplets and to try to create pairs of similar J values. If this difference is small (less than the spectrum resolution), the pair between the corresponding assigned atoms will be added to the J column of the Assignments Table. The J value will be the average of the two values. Only atom pairs located at 5-bond distance or least will be added. If not, Js will be added as ambiguous values.

This button will only be enabled when the active molecule is assigned, there are assigned multiplets in the 1H spectrum, and both, molecule and spectrum are linked.

The table will give priority to the homonuclear couplings. Thus, when the user writes in a H row the atom number (without specify a proton), the coupling will be done between the protons. To add a coupling H-C, the user will have to write the atomsymbol, for example, "C". The same for the cases in which the user writes in a C row, the coupling will be done between the carbons, by default.

In the case of CH2 with no equivalent protons: the user should type the correct proton notation in the coupling. If we want to add a coupling with the first proton of 13CH2, and the notation is cis/trans, the text should be "1.20(13cis)". If we type "1.20(13')", we will get a message saying "the atom 13' doesn't exist in the molecule".

Click on the 'Delete' button to delete any assignment selected on the table. To delete 'All the assignments', do 'Ctrl/Cmd+A' to select all the assignments and click on the Delete button. The same effect will happen if you follow the menu 'Assignments/Delete All Assignments' or if you right click on the molecule to display the context menu:

You can add (or replace) a second chemical shift assignment to a single nucleus. This feature will be very useful if you need to assign rotamers or for ambiguous assignments.

From the assignments table, you can hide "no protonated heteroatoms" or the the assignments of any specific spectrum:

It is possible to display the 1H and 13C assignments in the molecule by right clicking on it and selecting 'Atom Label/Show Assignment'

The Assignments table shows checkboxes for each row in the correlations that can be displayed as arrows in the molecule. Checking/unchecking these checkboxes will change the visibility of the correlations for each atom: