PARTITION OF ALKALI-METAL IONS AND COMPLEX-FORMATION WITH POLY(OXYETHYLENE) DERIVATIVES IN 1,2-DICHLOROETHANE

The partition equilibria of electrolytes of alkali-metal, dimethylammo nium and tetramethylammonium ions (M+) with dipicrylamine ion or picra te ion (X-) in 1,2-dichloroethane (1,2-DCE) have been investigated at 25.0 degrees C. The thermodynamic distribution constants of the electr olytes (M+.X-) were determined and the transfer free energy, Delta G(t )(0), of the individual ions into water-saturated 1,2-DCE were evaluat ed using the extrathermodynamic assumption. The value of Delta G(t)(0) of alkali-metal ion increases almost linearly with increasing dehydra tion energy of metal ion except for Lithium. The relatively small valu e of Delta G(t)(0) for lithium is interpreted by the hydration of the lithium ion in the 1,2-DCE phase. The complex formation constants of t he alkali-metal ions with poly(oxyethylene) derivatives in 1,2-DCE wer e evaluated by using the partition data of alkali-metal picrates. The order of the complex formation constant is Li+ < Na+ similar to K+ > R b+ > Cs+ for any POE compounds.