Surface Plasmon Resonance Allows to Correlate Molecular Properties With Diffusion Coefficients of Linear Chain Alcohols

Every biological and physicochemical process occurring in a fluid phase depends on the diffusion coefficient (D) of the species in solution. In the present work, a model to describe and fit the behaviour of (Formula presented.) as a function of structure and extensive thermodynamics parameters in binary solutions of linear chain organic molecules is developed. Supporting experimental and computational evidences for this model are obtained by measuring (Formula presented.) for a series of (Formula presented.) -alcohols through a novel surface plasmon resonance method and molecular dynamics simulations. This allows to propose a kind of combined analysis to explain the dependence of (Formula presented.) on various thermodynamic and structural parameters. The results suggest that for small linear systems in the range from 0 to 200 g mol−1 and under the assumption that the diffusive activation energy is a linear function of mass, (Formula presented.) is strictly dependent on the molecular shape and on the relative strength of the solute-solvent intermolecular forces represented by a parameter named R. The newly proposed approach can be utilized to characterize and monitor progressive changes in physicochemical properties for any investigated species upon increasing the dimension of the aggregate/molecule along a certain direction.