T. Gross et al., The influence of hydrogen bonds upon diffusion of simple amines and binarymixtures of ammonia, HIGH PR RES, 18(1-6), 2000, pp. 257-264
Self diffusion coefficients of monomethylamine and trimethylamine and intra
diffusion coefficients of some model mixtures containing ammonia have been
measured up to pressures of 200 MPa at temperatures between the melting pre
ssure curve and 423K by pulsed field gradient Spin Echo NMR. Compared to wa
ter and the lower alcohols the self diffusion coefficients of pure fluid am
monia shows no clear influence from hydrogen bonds in contrast to other the
rmodynamic properties. Therefore the methylated substance monomethylamine h
as been studied to see weather a more structured charge distribution on the
molecular surface compared to ammonia is needed to hinder fast rearrangeme
nts of the hydrogen bonds. For comparison also trimethylamine has been stud
ied where no hydrogen bonds can be formed. Additionally binary mixtures of
ammonia with methanol, benzene, trimethylamine and acetonitrile have been s
tudied to see effects of intermolecular interactions.