Chlorine Nuclear Spin-Spin Relaxation Mechanism in Mg(H2O)6SnCl6 as Studied by NQR and NMR Techniques

Abstract

AbstractThe 35Cl NQR spin-lattice relaxation time T1Q, spin-spin-relaxation time T2Q, and 1H NMR spin-lattice relaxation time in the rotating frame T1Q in Mg(H2O) 6SnCl6 were measured as functions of temperature. Above room temperature T2Q increased rapidly with increasing temperature, which can be explained by fluctuations of the local magnetic field at the chlorine nuclei due to cationic motions. From the T1Q experiments, these motions are found to be attributable to uniaxial and overall reorientations of [Mg(H2O)6 ] 2 + ions with activation energies of 95 and 116 kJ mol - 1 , respectively. Above ca. 350 K, T1Q decreased rapidly with increasing temperature, which indicates a reorientational motion of [SnCl6] 2 - ions with an activation energy of 115 kJ mol -1 .