Solvent extraction of strontium picrate from water into nitrobenzene in the presence of benzo-15-crown-5

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     

Extraction of barium picrate into nitrobenzene in the presence of benzo-15-crown-5

From extraction experiments with ¹³³Ba as a tracer, the extraction constant corresponding to the equilibrium Ba²⁺(aq) + 2A^-(aq) + 2L(nb) BaL₂ 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 (BaL₂ ²⁺, 2A^-) = 5.7. Furthermore, the stability constant of the benzo-15-crown-5 - barium complex in nitrobenzene saturated with water was calculated: log b_nb (BaL₂ ²⁺) = 14.6.     

Study of lithium complexes with benzo-15-crown-5 ether by X-ray diffraction and IR spectroscopy

The complex formation of lithium with benzo-15-crown-5 (B15C5) was investigated. The complexes LiB15C5H₂OX, where X = Cl^? (1), I^? (2), (3), (5), and LiBF₄B15C5 (4) were synthesized and studied by IR spectroscopy. Complexes 1–4 were examined by X-ray diffraction. According to IR spectroscopy data, the crown ether conformation changes upon dissolution. The interaction of the extracted complex with the solvent was identified.     

Hydration to benzo-15-crown-5, benzo-18-crown-6 and the benzo-18-crown-6-potassium ion complex in the low-polar organic solvents.

The coextraction of water with benzo-15-crown-5 (B1SC5), benzo-18-crown-6 (B18C6) and the B18C6-K+ complex into seven low-polar solvents, i.e., carbon tetrachloride (CTC), chloroform (CF), dichloromethane (DCM), 1,2-dichloroethane (1,2-DCE), benzene (BZ), chlorobenzene (CB) and o-dichlorobenzene (o-DCB), has been investigated. The mean hydration number, nH2O, of these solutes in the water-saturated organic solvents was determined. There is a trend that the nH2O values for any solutes increase with increasing the water concentration in the solvents. Those of B18C6 and B15C5 converge at almost 0.8 for B18C6 and 0.4 - 0.5 for B15C5 in the solvents with the relatively high water concentration, i.e., CF, 1,2-DCE, DCM, and nitorobenzene (NB). The nH2O value of B15C5 is about one-half of that of B18C6 for a given organic solvent. The dominant species of the B18C6-K+ complex in these solvents is non-hydrated. From these results, the hydration equilibrium constants, KH2O, in the organic solvents were estimated.     

苯并-15-冠-5和二苯并-18-冠-6萃取分离铟(III)的研究

本文用斜率法、饱和法以及通过与萃取合物相对应的冠醚配合物晶体的制备及其性质研究, 探讨了In^3^+的萃取机理, 测定并计算了表观萃取平衡常数, 将此萃取体系应用于铟和某些体系应用于铟和某些金属离子的萃取分离, 亦获得较好的结果.     

Studies on the complexes of 4′-substituted benzo-15-crown-5 ligands with sodium picrate and picric acid

Complexes of nine 4'-substituted benzo-15-crown-5 ligands with sodium picrate were prepared. A good linear relationship of the . values from the UV spectra and Hammett [_p - _m] values was observed. Charge transfer complexes of ten 4'-substituted benzo-l5-crown-5 ligands with picric acid were isolated in crystalline form. The color of the complexes depended on the nature of the substituents. All of the complexes were identified by elemental analyses, UV and IR spectra.     

Solvent extraction of sodium from water into nitrobenzene by using strontium dicarbollylcobaltate in the presence of benzo-15-crown-5

Summary From extraction experiments andg-activity measurements, the extraction constant corresponding to the 2Na⁺(aq)+SrL(nb)?2NaL⁺(nb)+Sr²⁺(aq) equilibrium taking place in the two-phase water-nitrobenzene system (L=benzo-15-crown-5; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as log K_ex(2Na⁺,SrL)=1.0±0.1. Further, the stability constant of the benzo-15-crown-5-sodium complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log b_nb(NaL⁺)=7.8±0.1.     

Effect of chelating anions on metal-crown interaction. Part III. X-ray structure of potassium picrate complex of benzo-15-crown-5

The crystal structure of [potassium(benzo-15-crown-5)₂](picrate) shows that in the complex the metal is sandwiched between two crowns and has no interaction with picrate.     

Solvent extraction of microamounts of yttrium from water into nitrobenzene by using hydrogen dicarbollylcobaltate in the presence of benzo-15-crown-5

Summary Extraction of microamounts of yttrium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B^-) in the presence of benzo-15-crown-5 (B15C5,L) has been investigated. The equilibrium data have been explained assuming that the complexes HL⁺, HL, YL³⁺, YL and YH_-1L are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.     

Solvent extraction of microamounts of cesium into nitrobenzene by using potassium and rubidium dicarbollylcobaltates in the presence of benzo-15-crown-5

Extraction of microamounts of cesium by nitrobenzene solutions of potassium dicarbollylcobaltate (K⁺B⁻) and rubidium dicarbollylcobaltate (Rb⁺B⁻) in the presence of benzo-15-crown-5 (B15C5, L) has been investigated. The equilibrium data have been explained assuming that the complexes ML⁺ and ML₂⁺ (M⁺ = K⁺, Rb⁺, Cs⁺) are present in the organic phase. The stability constants of the species ML⁺ and ML₂⁺ (M⁺ = K⁺, Rb⁺) in nitrobenzene saturated with water have been determined.     

Solvent effects on extraction of potassium picrate with benzo-18-crown-6. A new equation for the determination of ion-pair formation of crown ether-metal salt complexes in water

In order to determine the ion-pair formation constant of a crown ether-metal salt 1:1:1 complex in water, an equation is derived from regular solution theory and its predictions are verified experimentally by the solvent extraction method using benzo-18-crown-6 (B18C6), potassium picrate (KA), and various diluents of low dielectric constant. The distribution constants of B18C6 itself and the overall extraction constants of KA with B18C6 were determined at 25±0.2°C. The distribution constants of the neutral K(B18C6)A complex were calculated from these data. The literature value for the complex-formation constant of K(B18C6)⁺ in water and the ion-pair formation constant (K _K(B18C6)A ) for K(B18C6)A in water determined in this study were log K _K(B18C6)A =3.12±0.23 at 25°C). The distribution behavior of B18C6 and K(B18C6)A is explained in terms of regular solution theory. The molar volumes V (cm³·mol^–1) and solubility parameters (cal^1/2-cm^–3/2) are as follows: V _B18C6 =249±36; V _K(B18C6)A =407±56; _B18C6 = 11.5 ± 0.5; and _K(B18C6)A = 11.5 ± 0.5.     

Synergic solvent extraction of some lanthanides with mixtures of thenoyltrifluoroacetone and benzo-15-crown-5

Summary The synergic solvent extraction of Pr, Gd, and Yb with mixtures of thenoyltrifluoroacetone (HTTA) and a crown ether benzo-15-crown-5 (B15C5) in CCl₄, C₆H₆ and CHCl₃ has been studied. The composition of the extracted species has been determined asLn(TTA)₃·2B15C5 (Ln=Pr, Gd, and Yb). The values of the equilibrium constants have been calculated.

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Synergetische Extraktion von Lanthaniden mit Thenoyltrifluoraceton und Benzo-15-crown-5

Zusammenfassung Es wurde die synergetische Extraktion von Pr, Gd und Yb mit Mischungen ausHTTA und Benzo-15-crown-5 in CCl₄, C₆H₆ und CHCl₃ untersucht. Die Zusammensetzung der ExtraktionskomplexverbindungenLn(TTA)₃·2B15C5 (Ln=Pr, Gd und Yb) wurde bestimmt, und die Gleichgewichtskonstanten wurden berechnet.

     

Fundamental equilibrium analysis on the ion-pair extraction of dibenzo-18-crown-6 complex of alkali metal ions with picrate ion into 1,2-dichloroethane

The ion-pair extraction equilibria of dibenzo-18-crown-6 (DB18C6) complexes of Na⁺, K⁺, Rb⁺ and Cs⁺ (M⁺) with picrate ion (Pic⁻) into 1,2-dichloroethane (1,2-DCE) have been studied at 25.0°C. In the case of the Rb⁺ and Cs⁺ systems, the extraction results were interpreted by taking into consideration the formation of a (DB18C6)₂ -M⁺ complex in 1,2-DCE. The thermodynamic constants of extraction, , and ion-pair formation in 1,2-DCE, , of ion pairs of the DB18C6-M⁺ complexes with Pic⁻ were determined. By using the distribution coefficient of M⁺·Pic⁻ the thermodynamic formation constants of the DB18C6-M⁺ complexes in 1,2-DCE, , were evaluated. Consequently the component equilibrium constants of the ion-pair extraction were completely determined and a contribution of these constants to the difference of value was discussed. The value in 1,2-DCE is quite high compared with that in solvating solvents and log decreases linearly with increasing Gutmann donor number of solvents.     

Mass-spectrometric investigation of ionophoric derivatives of benzo- and dibenzocrown ethers. 4. 4′-Acyl derivatives of benzo-15-crown-5 and benzo-18-crown-6

The mass spectra of 4-acyl derivatives of benzo-15-crown-5 and benzo-18-crown-6 were studied by the method of direct analysis of the daughter ions (DADI). It was established that the fragmentation of the M⁺ ions of the investigated compounds under electron impact proceeds via the scheme of the McLafferty rearrangement with the simultaneous elimination of ethylene oxide. The degree of occurrence of the McLafferty rearrangement increases with an increase in the length of the side chain.See [3] for communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 989–901, July, 1987.     

f-Element/crown ether complexes: 21. Conformational changes in metal complexed versus hydrogen bonded benzo-15-crown-5 in the structure of [Y(OH2)3(NCMe)-(benzo-15-crown-5)][ClO4]3·benzo-15-crown-5·CH3CN

Crystalline [Y(OH₂)₃(NCMe)(benzo-15-crown-5)][ClO₄]₃·benzo-15-crown-5-CH₃CN can be obtained by slowly cooling a reaction mixture of Y(ClO₄)₃·n H₂O with benzo-15-crown-5 in a solution of acetonitrile and methanol (3 : 1) from 60°C to room temperature. The crystal structure of this complex has been determined at –150 and 20°C. The complex is triclinic,P . At –150°C the cell parameters area = 11.986(4),b = 12.071(7),c = 16.364(5) Å, = 93.56(3), = 98.68(3), = 109.68(4)°, vol = 2187 ų, andD _calc = 1.61 g cm^–3 forZ = 2 formula units. 3633 independently observed [F _o 5(F _o)] reflections were used in the final least-squares refinement leading to an agreement index ofR = 0.048. The Y(III) ion coordination geometry approximates a tricapped trigonal prism with three water molecules and three benzo-15-crown-5 oxygen atoms forming the prism, with the two remaining benzo-15-crown-5 oxygen atoms and the acetonitrile molecule completing the coordination as capping atoms. The three water molecules hydrogen bond a second crown ether molecule and two of the perchlorate anions. The two acetonitrile molecules have contacts with perchlorate oxygen atoms close enough for some weak interaction. One perchlorate is ordered, one is partially disordered as is the coordinated solvent molecule, and the third anion is totally disordered. The two unique crown ether molecules have distinctively different conformations.For Part 20, see reference [1].     

Anomalous fluorescent responses of 9-fluorenecarboxamide derivatives possessing benzo-15-crown-5.

A new fluorescent ionophore for alkaline earth metal ions, 4'-(9-fluorenecarboxamido)benzo-15-crown-5 (3), was synthesized; its photochemical behavior was investigated using UV, fluorescence, (1)H NMR, and (13)C NMR spectrometry. In the absence of a metal ion, the fluorene moiety showed weak fluorescence emission (fluorescence "Off" state). However, complexation with metal ions greatly enhanced the fluorescence intensity (fluorescence "On" state).     

Molecular structures of compounds formed by benzo-15-crown-5 with calcium salts

X-ray structural and spectroscopic results are given on the compound formed by benzo-15-crown-5 with calcium perchlorate, Ca(ClO₄)₂·C₁₄H₂₀O₅·2H₂O; the combination does not involve any substantial change in the dihedral angles in the macrocycle, as the coordination sphere is constructed as a result of supplementing the positions occupied by the macrocycle oxygen atoms with three other atoms (oxygen atoms from the perchlorate group and two water molecules). The results are compared with published data on the structures of the compounds formed by benzo-15-crown-5 with NaClO₄, Mg(NCS)₂, CuCl₂, Ca(NCS)₂ and Ca(3,5-dinitrobenzoate)₂.Translated from Teoreticheskaya i Éksperimental' naya Khimiya, Vol. 24, No. 2, pp. 242–247, March–April 1988.     

Extraction of lead from water into nitrobenzene by using strontium dicarbollylcobaltate in the presence of benzo-15-crown-5

Summary From extraction experiments andg-activity measurements, the extraction constant corresponding to the equilibrium Pb²⁺(aq)+SrL(nb)?PbL(nb)+Sr²⁺(aq)taking place in the two-phase water-nitrobenzene system (L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated aslog K_ex(Pb²⁺,SrL)=0.1±0.1. Further, the stability constant of the benzo-15-crown-5-lead complex in nitrobenzene saturated with water was calculated for a temperature of25 °C:log b_nb(PbL)=13.2±0.1.     

The effect of properties of water-organic solvent mixtures on the solvation enthalpy of 12-crown-4, 15-crown-5, 18-crown-6 and benzo-15-crown-5 ethers at 298.15 K

Crown ethers are preferential solvated by organic solvents in the mixtures of water with formamide, N-methylformamide, acetonitrile, acetone and propan-1-ol. In these mixed solvents the energetic effect of the preferential solvation depends quantitatively on the structural and energetic properties of mixtures. The energetic properties of the mixtures of water with hydrophobic solvents (N,N-dimethylformamide, dimethylsulfoxide, N,N-dimethylacetamide, hexamethylphosphortriamide) counteract the preferential solvation of the crown ether molecules. The effect of the hydrophobic and acid-base properties of the mixture of water with organic solvent on the solvation of 12-crown-4, 15-crown-5, 18-crown-6 and benzo-15-crown-5 ethers was discussed. The solvation enthalpy of one -CH₂CH₂O- group in water, N,N-dimethylformamide and hexamethylphosphortriamide is equal to −24.21, −16.04 and −15.91 kJ/mol, respectively. The condensed benzene ring with 15-crown-5 ether molecule brings about an increase in the exothermic effect of solvation of the crown ether in the mixtures of water with organic solvent.