抄録
The Steric effect of two di-Schiff base ligands having phenylene skeleton as extractant on ion-pair extraction of divalent metal cations into nitorbenzene with picrate anion was investigated. In these extraction systems, all of the extraction except for nickel was equilibrated within 1 h, and ratio of metal: ligand: picrate in the extracted species was 1: 2: 2 or 1: 3: 2. In the extraction of nickel, 2 or 10 hours needed to be equilibrated and the Steric effect of ligands resulted in the change of the extracted species. Namely, a difference between the favorable extracted species for kinetics and equilibrium appeared by the steric effect. Consequently, nickel was extracted quantitatively and the highly selectivity for nickel was obtained.