Mobility and Ionic Association of Lithium and Quaternary Ammonium Salts in Propylene Carbonate and γ‐Butyrolactone

The conductivities of lithium and quaternary ammonium salts have been measured in propylene carbonate and γ‐butyrolactone at 25°C over the concentration range of 10 −2 to 10 −3 mol dm −3 . The limiting molar conductivities and the ionic association constants were calculated by the expanded Fuoss‐Hsia equation. The mobility of anions in both solvents decreased in the following order: . The association constants increased in the following order: , , while those of the corresponding tetraethylammonium salts were leveled by electrostatic shielding effect of alkyl groups. These results were correlated with ionic radii obtained by MM2 calculation.