Multiaxial Reorientationsof ND+4 Ions Studied by 2H-NMR Spectroscopy

The density matrix formalism is used to simulate motional averaging in the H-NMR spectra of reorienting ND ions. The development of the spectra under increasing jump frequency about a single C or C axis is followed. Next we assume a hierarchy of axes in terms of activation energies sufficient to reach extreme narrowing conditions for some axes before activating jumps about a next one. Primary reorientations about the fastest C or C symmetry axes define the shape of spectra, the width of which is then stepwise reduced by fast reorientations about the subsequent axes in a postulated sequence of statistically uncorrelated jumps.