35Cl quadrupole resonance study of the thermally activated motion of the nitro group in chlorinated nitrobenzenes

摘要

The results of NQR studies of the thermoactivated motion of NO_2 groups in chlorine-containing nitrobenzenes are presented. A procedure for analyzing the experimental data is suggested. It uses the characteristic temperature of the minimum of the modulation contribution to the temperature dependence of the spin-lattice relaxation time T_1 of the resonant probe nuclei (~(35)Cl) bonded with the moving group by nonvalent interactions. The activation energy of the thermoactivated motion was correlated with the temperature of the minimum. The possibility of a temperature dependence of the activation energy of the NO_2 group was examined.