THERMODYNAMICS AND SELECTIVITY OF COMPLEXATION OF LITHIUM AND SODIUM THIOCYANATES WITH PHOSPHORUS-CONTAINING PODANDS AND COMPOUNDS MODELINGTHE TERMINAL GROUPS OF THESE PODANDS

A series of model compounds and heptadentate neutral phosphorus-contai ning podands that differ in the conformational rigidity of the termina l groups and in the coordination properties of the phosphoryl groups w ere synthesized. The thermodynamic parameters of complexation and the cationic selectivity of organophosphorus compounds and podands with re spect to LiNCS and NaNCS were studied by calorimetric titration in ace tonitrile at 298 K. The reasons for the high selectivity of certain ph osphorus-containing podands to the Li+ cation are discussed.