The vital importance of NMR in chemistry and biochemistry relies on the direct relationship between any given NMR experiment and the molecular information that can be extracted from it. Thus, every experiment is based on some NMR parameter, usually coupling constants or NOE, which is related to a specific molecular parameter (through-bond or through-space connectivities, chemical exchange, molecular motion ...). The quantitative measurement of such NMR parameters allows us to obtain valuable information about structural parameters such as dihedral angles, internuclear distances, relaxation and exchange rates. etc ... For this reason, the development of new and/or improved NMR methodologies is a key factor to be considered. Nowadays, the enormous suite of NMR experiments available for chemists, mostly using pulsed field gradients (PFG), found wide application in structural, conformational, stereochemical and dynamic studies on any type of chemical and biochemical compound.

Gradient enhanced NMR spectroscopy is widely used in liquid state spectroscopy for coherence pathway selection, solvent suppression, srtifact reduction, and diffusion weighting and has had a tremendous impact by improving the quality of NMR spectra.

Although the idea to alternatively use PFG instead of phase cycling ( 96ENC3585 ) for coherence selection in NMR experiments was been known for some time (78CPL9, 80CPL567, and 85JMR334), practical difficulties associated with PFG, such as eddy currents and B₀ shifts effects, prevented its successful application in high-resolution NMR experiments. Since approximately 1991, active shielded probeheads have been commercially available and, therefore, a lot of gradient-based NMR experiments have been recently proposed to demonstrate their usefulness in resolving an infinity of chemical questions with success. Thus, all advantages offering the incorporation of PFG as a powerful elements into high-resolution NMR pulse sequences combined with the advanced software tools available at the present time to acquire and process multidimensional NMR experiments with great simplicity has dramatically changed the concept of routine work in NMR for chemists.