Ionic conductivities and diffusion coefficients of alkyl substituted sulfonated resorcinarenes in aqueous solutions.

Highlights • Binary mutual diffusion coefficients of alkyl substituted sulfonated resorcinarenes solutions. • Conductivities of alkyl substituted sulfonated resorcinarenes solutions. • Limiting mobilities of the ETRA4− and PRRA4− ions derived independently from the diffusion and conductivity measurements. Abstract Resorcinarenes are macrocyclic compounds that form supramolecular complexes with a wide range of applications. In this paper, mutual diffusion coefficients and molar ionic conductivities are reported for aqueous solutions of the sodium salts of sulfonated resorcinarenes with two different alkyl groups: sodium C-tetraethyl-resorcin[4]arene sulfonate (Na 4 ETRA) and sodium C-tetrapropyl-resorcin[4]arene sulfonate (Na 4 PRRA). The diffusion coefficients and conductivities were measured at 25 °C for dilute solutions of the resorcinarenes (concentration < 0.010 mol·dm−3). The concentration dependence of the conductivities is accurately represented by equations for solutions of strong electrolytes, suggesting that association of the ETRA4− and PRRA4− ions with the Na+ counterions is negligible at the concentrations that were used. Furthermore, the limiting mobilities of the ETRA4− and PRRA4− ions derived independently from the diffusion and conductivity measurements are in good agreement. The change in the hydrodynamic radius of sulfonated resorcinarene caused by increasing the length of alky substituents is discussed. [ABSTRACT FROM AUTHOR]