DIFFUSION OF PSEUDOPLANAR MOLECULES - AN EXPERIMENTAL EVALUATION OF THE MOLECULAR EFFECTS ON DIFFUSION

Limiting mutual-diffusion coefficients of non-associated pseudo-planar molecules, ranging from benzene to anthracene, in various solvents have been measured at 298.2 K using the chromatographic peak-broadening method. For the non-associated solutes studied, there exists a linear relationship between the reciprocal of the diffusion coefficients and the molecular volume of the solutes. The diffusivities are found to be insensitive to the mass and dipole moment of the solute molecules. The data of the pseudo-planar molecules are compared with those of the pseudo-spherical solutes reported in the literature. The effects of molecular shape on diffusion are discussed.