Long-range 2D INADEQUATE in structure determination

It is demonstrated that the 2D INADEQUATE experiment utilizing long-range 13 C- 13 C spin-spin couplings is feasible and that it can solve structural assignment problems when one-bond connectivities do not provide sufficient clue for structure determination. In such cases, the long-range 2D INADEQUATE can be used instead of the standard 2D INADEQUATE since it also yields the one-bond connectivities in addition to the connectivities over more bonds. The two types of connectivities are easily distinguished according to satellite separations. Because of similar magnitudes of various long-range 13 C- 13 C couplings, the method of J -resolved INADEQUATE suggested earlier for such purpose is unlikely to provide unambiguous results. The proposed method is utilized for complete assignment of 13 C and 1 H NMR spectra of dicyclohexylphenylphosphine.