Diffusion in Polymethylene Chain Solutions with a Polar Component.

A hydrodynamic bead model based on Kirkwood-Riseman theory has been used to calculate the translational diffusion constant, , for solutes with polymethylene chains in solutions with a polar component. A comparison with the experimental values for nonpolar -alkanes in polar 2-propanol, tetrahydrofuran, chlorobenzene, chloroform, 1-octanol, quinoline, and chloroform (78 values) and polar primary alcohols in nonpolar benzene and -octane (24 values) gives an average absolute percentage difference of ∼3% between the 102 experimental and calculated values. Consideration of the solvent's temperature-dependent changes in the degree of aggregation due to hydrogen bonding was necessary for the -alkanes in 1-octanol. Good agreement was not found for primary alcohols in 1-octanol due to solute-solvent hydrogen bonding. A correlation that depends on the solutes' molar volumes instead of their chain lengths gives worse agreement than the bead model for the -alkanes in polar solvents and primary alcohols and -alkanes in nonpolar solvents.