Quinolines: T-1 NMR relaxation times of quinolines as a function of temperature in liquid and supercooled liquid state

The behaviour of the C-13 spin-lattice relaxation time as a function of tem perature is reported for eight quinoline family compounds. For a set of com pounds [1nT(1)(-1)] = f(T-1) is linear, for the other set [1nT(1)(-1)] = f( T-1) is best represented by two linear straight lines which intercept at a temperature T-t which depends upon the compound. For quinoline and lepidine the study has been also performed in the supercooled state. T-1(-1) shows a maximum for lepidine, and the relaxation time evolution as a function of T may be interpreted using a stretched exponential correlation function. (C ) 2000 Elsevier Science B.V. All rights reserved.