Anisotropic effect of the nitrate anion—manifestation of diamagnetic proton chemical shifts in the 1H NMR spectra of NO3− coordinated complexes

The anisotropic effect of the planar nitrate anion NO3− has been ab initio calculated employing the Nucleus-Independent Chemical Shift (NICS) concept of von Ragué Schleyer and visualized as Iso-Chemical-Shielding Surfaces (ICSSs) of various (de)shieldings. Complexation-induced shifts in the 1H NMR spectra of nitrate/metal complexes or nitrate/receptor supramolecules can be separated now into anisotropic influences of the suitably coordinated nitrate anions and effects originating from differential sources.