THE FIRST QUANTITATIVE ASSESSMENT OF THE INDIVIDUAL PROCESSES INVOLVED IN THE EXTRACTION OF ALKALI-METAL PICRATES BY ETHYL P-TERT-BUTYLCALIX(4)ARENE TETRAETHANOATE IN THE WATER-BENZONITRILE SOLVENT SYSTEM

Partition and distribution constants of alkali-metal (lithium, sodium, potassium, rubidium) picrates in the water-benzonitrile solvent syste m and ion-pair formation constants for these electrolytes in the water saturated organic phase at 298.15 K derived from distribution data ar e reported. Partition data are discussed with respect to transfer data for these electrolytes referred to the process involving the pure sol vents. The extraction of alkali-metal picrates from water to benzonitr ile by ethyl p-tert-butylcalix(4) arene tetraethanoate is investigated taking into account the extent of ion-pair formation of the alkali-me tal complex salt in benzonitrile. A quantitative assessment of the ind ividual processes which contribute to the overall extraction of alkali -metal picrates by the calixarene ester from water to benzonitrile is reported for the fist time.