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  • Author or Editor: E. Makrlík x
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Abstract  

From extraction experiments with 85Sr as a tracer, the extraction constant corresponding to the equilibrium Sr2+(aq) + 2A- (aq) + 2L (nb) Û SrL2 ,2+ (nb) 2A- (nb) in the two-phase water-nitrobenzene system (A- = picrate, L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex

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Abstract  

Extraction of microamounts of barium by a nitrobenzene solution of ammonium dicarbollylcobaltate (NH4 +B-) in the presence of 15-crown-5(15C5,L) has been investigated. The equilibrium data have been explained assuming that the complexes NH4L+, NH4L2 + and BaL2 2+ are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

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Abstract  

Extraction of barium by a nitrobenzene solution of bis-1,2-dicarbollylcobaltate in the presence of 15-crown-5 (15C5, L) has been investigated. The equilibrium data and the typical maxima concerning the dependencies of the Ba distribution ratios on the analytical concentration of 15C5 in the system under study can be explained assuming that the particles HL+, HL2 + and BaL2 2+ are extracted into the nitrobenzene phase. The values of the corresponding extraction and stability constants of the extracted species in nitrobenzene saturated with water have been determined.

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Abstract  

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Na+(aq)+HL+(nb)⇆NaL+(nb)+H+(aq) taking place in the two-phase water-nitrobenzene system (L=18-crown-6; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as logK ex (Na+,HL+)=0.1. Further, the stability constant of the 18-crown-6-sodium complex in nitrobenzene saturated with water was calculated: logβ nh(NaL+)=8.0.

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Abstract  

From extraction experiments and γ-activity measurements, the extraction constant of the Ba2+ (aq)+SrL2/2+(nb)⇆⇆BaL2/2+ (nb)+Sr2+(aq) equilibrium taking place in a two-phase water-nitrobenzene system (L=15-crown-5; aq-aqueous phase, nb=nitrobenzene phase) was evaluated as logK ex(Ba2+,SrL2/2+)=1.8. Further, the stability constant of the BaL2/2+ complex in water saturated nitrobenzene was calculated to be log βnh(BaL2 2+)=16.5.

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Abstract  

Extraction of sodium by the nitrobenzene solution of H+ bis-1,2-dicarbollylcobaltate (H+B) in the presence of 15-crown-5 (15C5, L) has been investigated. The equilibrium data have been explained assuming that the complexes HL+, HL2 + NaL+ and NaL2 +, NaL+ and NaL2 + are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

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Abstract  

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+(aq)+NaL+(nb)⇄ML+(nb)+Na+(aq) taking place in the two-phase water-nitrobenzene system (M+=Li+, K+, Rb+, Cs+; L=dibenzo-24-crown-8; aq=aqueous phase, nb=nitrobenzene phase) were evaluated. Further, the stability constants of the ML+ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the Cs+Rb+L+Na+ order.

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Abstract  

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium 2Na+(aq)+SrL2 2+(nb)⇆ 2NaL+(nb)+Sr2+(aq) taking place in the two-phase water-nitrobenzene system (L=15-crown-5; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as logK ex(2Na+,SrL2 2+)=−1.6. Further, the stability constant of the 15-crown-5-sodium complex in nitrobenzene saturated with water was calculated: log βnb(NaL+)=7.3.

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Abstract  

The extraction of microamounts of cesium by a nitrobenzene solution of sodium bis-1,2-dicarbollylcobaltate (Na+B) in the presence of 15-crown-5 (15C5, L) has been investigated. The equilibrium data have been explained assuming the complexes NaL+, NaL2 +, CsL+ and CsL2 + to be extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

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