Molecular dynamics in supercooled m-fluoroaniline

Molecular dynamics of meta-fluoroaniline (mFA) - the system which makes a s imple glass forming liquid - was examined by C-13 NMR and dielectric relaxa tion measurements. Spin-lattice relaxation times TI, nuclear Overhauser (NO E) factors of chemically non-equivalent carbons and dielectric retaxation i n mFA were measured as a function of temperature. The analysis showed that the correlation function describing molecular dynamics in mFA could he well described in terms of an asymmetric distribution of correlation rimes pred icted by the Davidson-Cole model. The overall correlation times of mFA. der ived from the simultaneous fitting of our TI, NOE, and dielectric data (as well as of the dielectric data obtained by Roessler's group) to the Davidso n-Cole model, follow the non-Arrhenius temperature type of the behaviour in accordance with the Vogel-Fulcher equation. (C) 2001 Elsevier Science B.V. All rights reserved.