A Conductance Study of the Association of Alkali Cations with 1,13-Dibenzo-24-Crown-8 in Acetonitrile

Article abstract of DOI:10.1007/BF00656776

A conductance study concerning the association of Na⁺, K⁺, Rb⁺, and Cs⁺ with 1,13-dibenzo-24-crown-8 in acetonitrile has been carried out at 35, 30, 25, 20, and 15 deg C.The observed molar conductivities Λ were found to decrease significantly for mole ratios less than unity.A model involving 1:1 stoichiometry has been used to analyze the conductivity data.The stability constant, K, and the molar conductivity Λ_c for each 1:1 complex were determined from the conductivity data by using a nonlinear least squares curve fitting procedure.The binding sequence, based on the value of log K at 25 deg C, is found to be Rb⁺>Cs⁺>K⁺>Na⁺.Values of ΔH⁰ and ΔS⁰ are reported and their significance is discussed.