A Generalized Bifunctional Correlation for Diffusivities of H-Bonded Aromatic Compounds in Polar Organic Solvents

Abstract

Limiting mutual (tracer) diffusivities of aromatic compounds in different polar solvents were measured by the Taylor dispersion method. The data of the nonassociated disc-like solutes in this work are shown to validate the recently established fractional molecular–hydrodynamic relation [Ind. Eng. Chem. Res. 2019, 58, 20423–20440]. A new model is proposed to account for the tracer diffusivities of the aromatic solutes capable of H-bonding in various polar organic solvents. The model contains two functions: one for the intrinsic nonassociated diffusivity behavior of each individual solute molecule and another for the effect due to its solute–solvent H-bonding on diffusivity. A general equation developed from this model is demonstrated to be capable of correlating and calculating a total of 358 diffusivity data of H-bonded aromatic solutes, which have been measured here and collected from the literature, in different organic solvents at various temperatures to a standard deviation of 3.25% only.