Spectral Editing Using J-Modulated Spin-Echos

Spectral Editing Using J-Modulated Spin-Echos 

The favorable properties of 180 refocussing pulses have been exploited in two main efforts obtaining more spectral information by causing spectra to depend on J and the number of coupled nuclei, and secondly, discussed later, in polarization transfer methods. 

Of course, the simplest way to make spectra depend on J, either homonuclear or heteronuclear, is to run a coupled spectrum. The low sensitivity of 

Fortunately, spin echo pulse sequences have 

The investigator thus has the option of searching for quaternaries which might be masked by protonated carbons by setting X = 1/2J or, it might be more desirable to sort by CH/CH3 and CH2/C. It is also possible to combine normal spin-echo and modulated spin-echo spectra to arrive at edited subspectra containing only carbons of one type (6,14-17). 

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