NMR SPIN-LATTICE RELAXATION OF THE XE-129 NUCLEUS OF XENON GAS DISSOLVED IN VARIOUS ISOTROPIC LIQUIDS

The spin-lattice relaxation time of the Xe-129 nucleus of natural xeno n gas dissolved in various isotropic liquids, acetonitrile, benzene, c arbon tetrachloride and cyclohexane, was studied as a function of temp erature at the magnetic fields of 9.4 and 4.7 T. The utilization of hy drogenated and deuterated benzene and cyclohexane reveals that the int ermolecular Xe-129-H-1 dipole-dipole interaction constitutes an import ant relaxation mechanism in hydrogenated solvents. According to this i nterpretation the interaction is rather strongly temperature-dependent , and increases with increasing temperature. An important observation of an experimental nature is also noted, namely convective flow presen t in non-spinning sample tubes at elevated temperatures disturbs inver sion-recovery measurements and leads to erroneous and unreliable relax ation time values.