The effect of the solvent in the binding of anions and ion-pairs with a neutral [2]rotaxane

In this work we report the binding properties of rotaxane 1 towards a series of tetraalkylammonium salts of Cl-, OCN- and NO3- anions in acetone and a CHCl3/MeOH solvent mixture....

Viscometric and Conductometric Studies of Solvation Behaviour of Tetraalkylammonium Salts in the Binary Mixtures of Dimethylsulfoxide and Methanol at 298.15 K

Molar conductance and viscosity of some tetraalkylammonium perchlorates (R4NClO4 where R = Methyl, Ethyl, Propyl, Butyl) have been measured in the concentration range (30–500) × 10−4 mol kg−1 at 298.15 K in the binary mixtures of dimethylsulfoxide (DMSO) + methanol (MeOH) containing 0, 20, 40, 50, 60, 80 and 100 mol% methanol. Conductance data has been analyzed using the Shedlovsky equation and the viscosity data by Jones-Dole equation. The limiting ionic conductances ($\lambda_{\pm}^{o}$) were used to calculate the solvated radii (ri) of the ions. The A and B coefficients of the Jones-Dole equation are positive in all salts. The A coefficients are in reasonable good agreement with the limiting theoretical values (Aη) calculated using Falkenhagen-Vernon equation. The variation of the ionic B± coefficients as well as the actual solvated radii (ri) with solvent composition in DMSO + MeOH mixtures show the preferential solvation of tetraalkylammonium ions by MeOH and MeOH-rich region of the mixtures. The tetraalkylammonium ions exhibit solvation in the order Me4N+ > Et4N+ > Pr4N+ > Bu4N+.