PULSED-FIELD GRADIENTS - A NEW TOOL FOR ROUTINE NMR

A complete review of 1D and 2D gradient-based NMR experiments publishe d since 1990 is provided. The ease of implementation and the excellent and reproducible results obtained from such experiments offer a power ful tool for the study of molecular structures and dynamics. Thus, whe n sufficient sample concentration is available, ultra-clean spectra ar e obtained in very short acquisition times, making the experiments sui table for automated data acquisition. For these reasons, the concept o f routine NMR work for chemists has been dramatically changed in the l ast few years and, with the correct choice of the experiments to be pe rformed, a large number of chemical questions can be resolved in consi derably reduced times. However, sensitivity and resolution are depende nt on where the PFGs are incorporated into the pulse sequences and, th erefore, these two important factors need to be considered in highly d emanding applications. Illustrative examples of the most interesting a pplications to typical organic compounds are given.