Thermodynamics and selectivity of lithium and sodium thiocyanate complexing with phosphorus-containing podands and compounds modeling the podand terminal groups

A number of heptadentate neutral phosphorus-containing podands and model compounds have been synthesized. The thermodynamic parameters of complexing and cationic selectivity of the compounds and podands with LiNCS and NaNCS have been studied in acetonitrile at 298 K by means of calorimetric titration. The reasons for high selectivity of certain phosphorus-containing podands with respect to lithium cation are discussed. 17 refs.; 1 fig.; 1 tab