Temperature-dependence of ion-pair formation of simple thiocyanate salts in liquid ammonia

Abstract

The concentration-dependences of the electrical conductances of NH 4SCN, (CH 3) 4NSCN, KSCN and NaSCN solutions in liquid ammonia were recorded in the temperature interval between 213 and 238 K. Computer evaluation of the data via the Lee–Wheaton equation led to the ion-pair formation constants ( K), the ion–ion distance parameters ( R) of the species and the limiting equivalent ionic conductances (Λ o) of their solutions. With increasing temperature, the K values were found to increase while the R values decrease, indicating that a temperature increase facilitates the desolvation of solvated species, promoting ion–ion interactions, i.e. ion-pair formation.