Measurements of 14 N decoupling 1 H– 19 F HOESY It often happens that 1 H NMR analysis is prevented with the severe line broadening of 1 H signal that is bound to 14 N atom. In such a case, the 14 N decoupling technique is useful. 1 H– 19 F 1D-HOESY spectra with and without 14 N decoupling are shown in Fig. 1. Selective excitation was done at F5 (Fig. 1:upper) and F6 (Fig. 1:bottom), respectively. The amide 1 H signal intensity in 1D-HOESY is increased by twice, compared to that measured without 14 N decoupling. Since NOE measurements have general difficulty in low sensitivity, the 14 N decoupling technique is useful for observation of cross peaks with 1 H– 14 N signals. 2D-HOESY with 14 N decoupling measurement is also available (Fig. 2).