Correlated Spectroscopy 2-D

Of course, you can find yourself looking at spectra that are complex enough to warrant numerous decoupling experiments for elucidation. In these circumstances, running a single correlated spectroscopy (COSY) 2-D experiment as an alternative might well be the answer. A full explanation of the theoretical 

In this case we pulse at the beginning of the evolution time and then wait before doing our acquisition pulse. If we vary this wait by incrementing it for each successive cycle, we can change what we see in the FID. This is what generates our second dimension. In the case of the COSY experiment, we allow the coupling information to evolve during this period and then read what has happened to it with the acquisition pulse. 

Once we have acquired the data, we have two time domains (one from the normal acquisition time, the other from the incremented delay, hence the data is now 2-D ). As with normal spectra, we need to look at the data in the frequency domain. We do this by Fourier transformation, first in one dimension and then in the other. The resultant data can be portrayed or plotted in one of two different formats. 

Spectrum 8.2 A COSY contour plot of the morpholine compound. 

Another disadvantage is that for solving certain stereochemistry problems, it is necessary to be able to not only establish connectivity but to measure couplings fairly accurately so that the data can be used in conjunction with the Karplus curve. Whilst this is possible using a phase sensitive COSY (Note - 

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