Correlation of connected transitions by two-dimensional NMR spectroscopy

A novel and general concept of restricting coherence transfer in nuclear spin systems is described. It opens new possibilities for editing one- and two-dimensional NMR spectra. For example, the widely applied two-dimensional correlation experiment COSY can be modified such as to restrict coherence transfer to take place exclusively between connected transitions in the energy level diagram. Such two-dimensional spectra possess ideal features for assignment of complex scalar coupling networks and for computer assisted analysis. Experimental 1H spectra of a cyclic decapeptide are presented. Other applications of the general filtering concept are briefly discussed.