N,N,N',N'-Tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide as Very Effective Extraction Agent for Trivalent Europium and Americium.

Solvent extraction of microamounts of Eu3+ and Am3+ from water into nitrobenzene by means of a mixture of hydrogen dicarbollylcobaltate (H+B-) and N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide (L) was studied. The equilibrium data were explained assuming that the species HL+, H2L2+, HL+2, ML3+2, and ML3+3 (M3+ = Eu3+, Am3+; L = N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed.

Extraction and DFT study on the complexation of Zn(2+) with beauvericin.

From extraction experiments and g-activity measurements, the exchange extraction constant corresponding to the equilibrium Zn2+(aq) + 1 . Sr2+(nb) <-> 1 . Zn2+(nb) + Sr2+(aq) taking place in the two-phase water-nitrobenzene system (1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (Zn2+, 1 .

Synergistic extraction of europium and americium into nitrobenzene by using hydrogen dicarbollylcobaltate and dodecaethylene glycol.

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of dodecaethylene glycol (DDEG, L) has been investigated. The equilibrium data have been explained assuming that the species HL+, H2L2+, ML3+ and MH-1L2+ (M3+ = Eu3+, Am3+; L = DDEG) are extracted into the organic phase. The values of extraction and stability constants of the complex species in nitrobenzene saturated with water have been determined.

Synergistic extraction of calcium and strontium into nitrobenzene by using hydrogen dicarbollylcobaltate and 1,2-bis(diphenylphosphino)ethane dioxide.

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of 1,2-bis(diphenylphosphino)ethane dioxide (DPPEtDO, L) has been investigated. The equilibrium data have been explained assuming that the species HL+, HL+2, ML2+2 and ML2+3 (M2+ = Ca2+, Sr2+) are extracted into the organic phase. The values of extraction and stability constants of the cationic complexes in nitrobenzene saturated with water have been determined.

Extraction and DFT Study on the Complexation of the TRIS+ Cation with a Hexaarylbenzene-Based Receptor.

From extraction experiments and -activity measurements, the exchange extraction constant corresponding to the equilibrium TRIS+(aq) + 1.Cs+(nb) <-> 1.TRIS+(nb) + Cs+(aq) taking place in the two-phase water-nitrobenzene system (TRIS+ = (HOCH2)3C-NH3+, 1 = hexaarylbenzene - based receptor; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (TRIS+, 1.

Solvent Extraction of Some Divalent Metal Cations into Nitrobenzene by Using a Synergistic Mixture of Strontium Dicarbollylcobaltate and p-tert-Butylcalix[4]arene-tetrakis (N,N-Diethylacetamide).

From extraction experiments and g-activity measurements, the exchange extraction constants corresponding to the general equilibrium M2+(aq) + 1•Sr2+(nb) <-> 1•M2+(nb) + Sr2+(aq) taking place in the two-phase water-nitrobenzene system (M2+ = Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Mn2+, Co2+, Ni2+; 1 = p-tert-butylcalix[4]arene-tetrakis(N,N-diethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) were determined. Further, the stability constants of the 1•M2+ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the series of Cu2+ < Ba2+ < Zn2+ < Ni2+ < UO22+ < Co2+ < Mn2+ < Cd2+ < Ca2+ < Pb2+.

Complexation of the Silver Cation with Dibenzo-30-crown-10: Extraction and DFT Study.

From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ag+(aq) + 1.Cs+(nb) <-> 1.Ag+ (nb) + Cs+(aq) taking place in the two-phase water-nitrobenzene system (1 = dibenzo-30-crown-10; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex (Ag+, 1.

Synergistic extraction of calcium and strontium into nitrobenzene by using hydrogen dicarbollylcobaltate and n,n´-dimethyl-n,n´-diphenyl-2,6-dipicolinamide.

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of N,N´-dimethyl-N,N´-diphenyl-2,6-dipicolinamide (MePhDPA, L) has been investigated. The equilibrium data have been explained assuming that the species HL+, HL+2, ML2+2 and ML2+3 (M2+ = Ca2+, Sr2+) are extracted into the organic phase. The values of extraction and stability constants of the cationic complex species in nitrobenzene saturated with water have been determined.

Theoretical study on the protonation of cucurbit[7]uril.

By using quantum mechanical DFT calculations, the most probable structures of the cucurbit[7]urilH3O+ and cucur-bit[7]uril'(H3O+)2 cationic complex species were derived. In these two complexes having a plane symmetry, each of the considered H3O+ cations is bound by relatively strong hydrogen bonds to the corresponding carbonyl oxygens of the parent cucurbit[7]uril macrocycle.

Solvent extraction of calcium and strontium into nitrobenzene by using a synergistic mixture of hydrogen dicarbollylcobaltate and bis(diphenylphosphino)methane dioxide.

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of bis(diphenylphosphino)methane dioxide (DPPMDO, L) has been investigated. The equilibrium data have been explained assuming that the species HL+, HL2+, ML2(2+), ML3(2+) and ML4(2+) (M2+ = Ca2+, Sr2+) are extracted into the organic phase. The values of extraction and stability constants of the cationic complexes in nitrobenzene saturated with water have been determined.

Complexation of the ammonium cation with dibenzo-18-crown-6: extraction and DFT study.

From extraction experiments and gamma-activity measurements, the extraction constan corresponding to the equilibrium NH4(+)(aq) + 1*Na(+)(nb) <=> 1*NH4(+)(nb) + Na(+)(aq) taking place in the two-phase water - nitrobenzene system (1 = dibenzo-18-crown-6, aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K(ex) (NH4(+),1*Na(+)) = -0.1 +/- 0.1.

Bambus[6]uril as a novel macrocyclic receptor for the nitrate anion.

By using quantum mechanical DFT calculations, the most probable structure of the bambus[6]uril x NO3(-) anionic complex species was derived. In this complex having C3 symmetry, the nitrate anion NO3(-), included in the macrocyclic cavity, is bound by twelve weak hydrogen bonds between methine hydrogen atoms on the convex face of glycoluril units and the considered NO3(-) ion.

Solvent Extraction of Calcium into Nitrobenzene by Using an Anionic Ligand Based on Cobalt Bis(Dicarbollide) Anion with Covalently Bonded CMPO Function.

From extraction experiments and γ-activity measurements, the exchange extraction constantcorresponding to the general equilibrium Ca2+(aq) + 2HL(nb) <-> CaL2(nb) + 2H+(aq) taking place in the two-phase water-nitrobenzene (L- = anionic ligand based on cobalt bis(dicarbollide) anion with covalently bonded CMPO function; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (Ca2+, 2HL) = 0.0 ± 0.1.

Experimental and theoretical study on the complexation of beauvericin with the ammonium cation.

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium NH4+(aq) + NaL+ (nb) <-> NH4L+(nb) + Na+ (aq) taking place in the two-phase water-nitrobenzene system (L = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (NH4+, NaL+) = 1.5 ± 0.1.

Synergistic Extraction of Some Univalent Cations into Nitrobenzene by Using Sodium Dicarbollylcobaltate and Dibenzo-21-crown-7.

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+ (aq) + 1•Na+ (nb) <-> 1•M+ (nb) + Na+ (aq) taking place in the two-phase water-nitrobenzene system (M+ = Li+, H+, NH+4, Ag+, K+, Rb+, Tl+, Cs+; 1 = dibenzo-21-crown-7; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the 1•M+ complexes in water - saturated nitrobenzene were calculated; they were found to increase in the series of H+ < Ag+ < Li+ < Cs+ < K+, Rb+ < NH+4 < Tl+.

Experimental and Theoretical Study on the Complexation of the Thallium Cation with Dibenzo-18-crown-6.

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Tl+(aq) + 1.Na+(nb) <-> 1.Tl+(nb) + Na+(aq) taking place in the two-phase water-nitrobenzene system (1 = dibenzo-18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex(Tl+, 1.

Synergistic Extraction of Strontium into Nitrobenzene by Using Hydrogen Dicarbollylcobaltate and N,N,N´,N´-Tetracyclohexyl-oxybis(o-phenyleneoxy) diacetamide.

Extraction of microamounts of strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of N,N,N´,N´-tetracyclohexyl-oxybis(o-phenyleneoxy)diacetamide (abbrev. barium ionophore I, L) has been investigated. The equilibrium date have been explained assuming that the species HL+, SrL2+ and SrL2+2 are extracted into the organic phase.

N,N,N',N'-Tetra-isobutyl-pyridine-2,6-dicarboxamide.

In the title compound, C(23)H(39)N(3)O(2), the amide O atoms are displaced by 1.020 (1) and 1.211 (1) Å from the mean plane of the central pyridine ring.

Solvent extraction of calcium and strontium into nitrobenzene by using a synergistic mixture of hydrogen dicarbollylcobaltate and 2,6-(diphenylphosphino)pyridine dioxide.

Solvent extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of 2,6-(diphenylphosphino)pyridine dioxide (DPPPDO, L) has been investigated. The equilibrium data have been explained assuming that the species HL+, HL+2, CaL2+2, CaL2+3, SrL2+2, SrL2+3 and SrL2+4 are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

Individual extraction constants of some univalent anions in the two-phase water-phenyltrifluoromethyl sulfone system.

From extraction experiments and g-activity measurements, the extraction constants corresponding to the general equilibrium Cs+(aq) + A- (aq) <-> Cs+(org) + A- (org) taking place in the two-phase water-phenyltrifluoromethyl sulfone (FS 13) system (A-= I-, ClO4-, MnO4-, Br-3, I-3, picrate, tetraphenylborate (BPh-4); aq = aqueous phase, org = FS 13 phase) were evaluated. Furthermore, the individual extraction constants of these 7 anions in the mentioned two-phase system were calculated; they were found to increase in the series of I-< ClO4- < Br-3 < MnO4-, picrate < I-3 < BPh-4.

DFT Study on the Complexation of Bambus[6]uril with the Perchlorate and Tetrafluoroborate Anions.

By using quantum mechanical DFT calculations, the most probable structures of the bambus[6]uril.ClO4- and bambus[6]uril.BF4- anionic complex species were derived.

Interaction of hydrated protons with octyl-phenyl-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO): NMR and theoretical study.

Interaction of octyl-phenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO, the 'classical' rare metal extraction agent) with fully ionized hydrated protons (HP) was studied in acetonitrile-d(3) using (1)H, (13)C, (31)P NMR, PFG NMR and magnetic relaxation. The experimental results were confronted with high-precision ab initio DFT calculations. Relative chemical shifts of NMR signals of CMPO (0.

A combined experimental and DFT study on the complexation of the hydrazinium cation with a hexaarylbenzene - based receptor.

From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium N2H+5 (aq) + 1.Cs+(nb) <-> 1.N2H+5 (nb) + Cs+(aq) taking place in the two-phase water-nitrobenzene system (1 = hexaarylbenzene - based receptor; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (N2H+5, 1.

Synergistic extraction of europium into nitrobenzene by using hydrogen dicarbollylcobaltate and 2, 6 - (diphenylphosphino)pyridine dioxide.

Solvent extraction of microamounts of europium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of 2, 6 - (diphenylphosphino)pyridine dioxide (DPPPDO, L) has been investigated. The equilibrium data have been explained assuming that the species HL+, HL+2, EuL3+3 and EuL3+4 are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

Extraction and DFT Study on the Complexation of the Sodium Cation with Dibenzo-18-crown-6.

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Na+(aq) + A-(aq) + 1(nb) left arrow over right arrow 1•Na+(nb) + A-(nb) taking place in the two-phase water-nitrobenzene system (A- = picrate, 1 = dibenzo-18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as was log Kex (1•Na+, A-) = 1.7 ± 0.1.