Journal of Physical Chemistry A, Vol.102, No.45, 9087-9090, 1998
Diffusion of disubstituted aromatic compounds in ethanol
Limiting mutual diffusion coefficients of aromatic compounds containing two polar groups in ethanol have been measured at 298.2 K by using the chromatographic peak-broadening method. The data are compared with those of nonpolar pseudoplanar solutes, and the effects due to hydrogen bonding on diffusion together with the solvation numbers are evaluated. It is found that the effects and the solvation numbers are generally large and dependent on the nature and position of the polar groups attached. For all hetero-disubstituted aromatic isomers studied, the diffusivity trends are p < m < o, which are different from the previous results for the nonpolar isomers. The findings are discussed in terms of the chemical structure of the solutes as well as the intra- and intermolecular interactions.
Keywords:BINARY-LIQUID MIXTURES, MUTUAL DIFFUSION, TRACER DIFFUSION;MOLECULAR ASSOCIATION, DIPOLE-MOMENT, COEFFICIENTS;HYDROCARBONS, SOLUTES