35Cl NQR and pseudorotation in crystalline molecular complexes of antimony trichloride with aromatic hydrocarbons

The pseudorotation of chlorine atoms in molecular complexes of SbCl3 with benzene and its substituted derivatives was used as an example to consider the effect of the thermally activated intramolecular mobility on the quadrupole spin-lattice relaxation of moving nuclei. The data obtained by nuclear quadrupole resonance were analyzed using the model that implies the existence of a temperature dependence of the activation energy for pseudorotation. This model accounts for the great preexponential factors in the expression for the thermal activation component of the relaxation rate of chlorine nuclei found for some complexes and provides the way for rapid estimation of the pseudorotation activation energy in the characteristic temperature points using both relaxation and spectral NQR parameters.