Values up to 5 Hz. Large values (> 3.2 Hz) correspond to trans conformations, whereas intermediate couplings are expected if rotamer averaging takes place or if the torsion angle don't correspond to either trans or gauche conformation.

2D 1H-detected long-range 13C-13C correlation ( 92JACS6923 ).

94JB787-4

2D spin-echo difference 1H-13C CT-HSQC experiment ( 96JB256 ).

3D HN(CO)CAC_ali experiment ( 97JACS5055 )