Inverse editing of protons in two-dimensional homonuclear and heteronuclear relayed COSY spectra

Several 1D and 2D inverse proton editing pulse sequences have recently been introduced. One of these, the REPAY sequence, allows the individual editing of XH or XH2 groups. Some new 2D combinations of one‐ and two‐dimensional REPAY experiments with a COSY or TOCSY transfer are described. These combinations provide various possibilities for structural elucidation: the determination of heteronuclear long‐range coupling constants nJ(CH) (n = 2, 3), the editing of XH or XH2 groups in two‐dimensional H,H COSY spectra and the editing of XH or XH2 groups in X,H COSY spectra followed by a relayed transfer. In contrast to earlier versions of SHIPPED‐COSY experiments, the spectra show improved sensitivity and offer the possibility of selecting XH2 groups only, and contain no 1J(XH) coupling because of heteronuclear X decoupling.