Digital JC

Digital JC (Not available in Mnova Lite): is a new method for detecting spin connectivities in 1H NMR spectra. The main goal of this method is to convert a 1D spectrum into a 2D-like plot in which it is easy to correlate multiplets containing the same splitting. Its main purpose is to rule out couplings between multiplets. It is suitable for human inspection.

The basic idea is to generate a 2D plot from a 1H NMR spectrum in such a way that the horizontal dimension conveys the chemical shifts whereas the vertical one represents the separation between peaks in the spectrum (splittings from now on). Basically, it is a special kind of 2D 1H - D experiment (where D = splitting).

Just load your 1H NMR spectrum and follow the menu 'Analysis/More Tools/Digital JC' to display the J Correlation dialog box to select the desired algorithm and display options:

As usual, a picture is worth a thousand words:

In this figure we have simulated 1D spectrum with two coupled spins, A = 80 Hz and B = 30 Hz. JAB = 10 Hz.

In the new 2D plot (JC from now on) we can see two cross peaks at the positions of A and B respectively and at the same d-trace (vertical dimension or splitting dimension).

It's very important to remember that what we see in the JC plot are just splittings, not Coupling Constants, even though in some cases these splittings can coincide with coupling constants.