Orientational dynamics of hydrogen‐bonded liquids – A comparative study of dielectric and nuclear magnetic relaxation in n‐butanol‐tetrachloromethane mixtures

Abstract

AbstractComplex dielectric spectra up to 20 GHz are measured at 25°C for n‐butanol tetrachloromethane mixtures. Within this frequency range the spectra can be described by two Debye‐processes. Their relaxation times τ(1)1 and τ(2)1 are compared with the hypothetical single‐particle relaxation time of the dipoles τs1 estimated from deuteron magnetic relaxation rates in these mixtures. The results indicate a collective nature of the primary relaxation time τ(1)1 due to cooperative motion of several molecules. Although not accurate in detail, some theoretical models can reproduce major features of the concentration dependence of τ(1)1. In these models, τ(1)1 is coupled to τs1 via the Kirkwood correlation factor g1 which can be determined independently from the static permittivity. There is no obvious interrelation between τs1 and the secondary relaxation time τ(2)1 the nature of which remains puzzling.