Diffusion and conductance properties of aqueous solutions of tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(2-(methylthio)ethyl)resorcinarene

Abstract Interdiffusion coefficients and molar conductivities of the macrocycle tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(2(methylthio)ethyl)resorcinarene (H 8 Na 4 RSTio) in non-buffered aqueous solutions at 25.00 °C and at concentrations from (0.001 to 0.020 mol·dm −3 ) have been measured. The concentration dependence of the conductivities is accurately represented by equations for solutions of strong electrolytes, suggesting that there are no association between anionic species from macrocyclic molecule and Na + counterions at the concentrations that were used. Furthermore, the limiting conductivities of the H 8 RSTio 4− ions derived independently from the diffusion and conductivity measurements, as well as the Nernst diffusion coefficients derived from diffusion (1.296 × 10 −9 ) m 2 ·s −1 and from conductance (1.298 × 10 −9 ) m 2 ·s −1 , are in good agreement. Limiting diffusion coefficient of H 8 RSTio 4− anion was used, together with the Stokes–Einstein equation, to determine the equivalent hydrodynamic radius.