CHANGES IN THE ANISOTROPY OF QUINOLINE MOLECULAR-REORIENTATION IN THELIQUID-STATE AS PROBED BY C-13 AND N-14 NUCLEAR-MAGNETIC-RESONANCE RELAXATION-TIMES

At the same temperature T(t) (290 K), the derivatives with respect to the temperature of the C-13 T1 spin-lattice relaxation times, of the N -14 spin-spin relaxation time and of the saturated specific heat of qu inoline show a large variation. The calculations of the rotational dif fusion coefficients from the nuclear magnetic resonance data show that the molecular motion is more anisotropic below T(t) than above. A lar ge change is observed at T(t) for the energy barrier of the rotation a round one of the molecular axes. This may be interpreted as due to a c hange in molecular organization at T(t).