Abstract
The temperature dependence of the spin-lattice relaxation time, T1, for 35Cl nuclei was measured in the two crystalline phases of p-chlorobenzenesulphonyl chloride. The observed behaviour of T1 is ascribed to the triggering of thermally activated semi-external molecular motions. The results of the present study support the conclusion drawn from previous observations of the nuclear quadrupole resonance frequency, nu Q(T)-namely that the triggering of wagging semi-external movements occurs in this compound at temperatures higher than 160K.