Exclusive correlation spectroscopy
Exclusive correlation spectroscopy is an NMR correlation experiment introduced by O. W. Sørensen, Christian Griesinger, Richard R. Ernst and coworkers for the accurate measurement of small J-couplings.
The idea behind the experiment is to measure an unresolved coupling with the help of a larger coupling which is resolved in a dimension orthogonal to the small coupling. Three active nuclei are needed and the pulse sequence must be able to transfer magnetization from I to S without changing the spin state of X, otherwise the ECOSY pattern will vanish.
