Low-voltage thin-layer electrophoresis of inorganic anions on silica gel-G and titanium (IV) tungstate layers: separation of coexisting F−, Cl−, Br− and I−, I−, IO3− and IO4−, Fe(CN)64− and Fe(CN)63−

The electrophoretic behavior of twenty anions has been studied on silica gel-G, titanium (IV) tungstate and silica gel-G- titanium (IV) tungstate admixture layers using 0.1 M solutions of oxalic acid, citric acid, tartaric acid, succinic acid and acetic acid as background electrolyte. The mechanism of migration is explained in terms of adsorption and the solubility of various sodium or potassium salts of the anions in water. Titanium (IV) tungstate behaves only as an adsorbent and not as an ion exchanger. Being a cation exchanger, there is no exchange phenomenon occurring with anions. The migration of halides increase linearly with an increase in the bare ion radii of these ions. Differential migration of the anions on silica gel-G layers led to binary, ternary and quaternary separations of similar anions such as F⁻ – Cl⁻ – Br⁻ – I⁻, I⁻ – IO₃⁻ – IO₄⁻, BrO₃⁻ – IO₃⁻ and Fe(CN)₆³⁻ – Fe(CN)₆⁴⁻. The two cyanoferrate ions are separated from industrial waste water and from fixer and bleach solutions. The migration of anions has also been found to be in accordance with their lyotropic numbers.

     

The behaviour of cellulose in hydrated melts of the composition LiXċn H2O (X=I−, NO3−, CH3COO−, ClO4−)

The dissolution behaviour of cellulose in low temperature molten salts was investigated. Depending on the chosen anions in the melt, cellulose shows different reaction behaviour in different Li⁺containing melts. Dissolution of the polymer was observed in molten LiClO₄3H₂O and molten LiI2H₂O. In the hydrated melts of LiCH₃COO2H₂O and LiNO₃3H₂O a fine distribution of cellulose was stated. Cellulose can be regenerated by cooling the melt and removing the salt by dissolution in water.The structure of the recrystallized product is determined by the used low temperature molten salt.     

Binding of multiple SO2 molecules to small gold cluster anions (AuN−, AuNOH−, N = 1-8)

The binding of SO₂ on gas-phase gold cluster anions, Au_N⁻, and their hydroxide counterparts, Au_NOH⁻, have been studied using density functional theory combined with flow reactor/time-of-flight mass spectrometry techniques. SO₂ is adsorbed on all of the Au_N⁻ and Au_NOH⁻ clusters (N = 1-8) and the hydroxide clusters are more active than the bare anionic clusters. Successive additions of SO₂ molecules (up to four) have been analyzed. In all cases, anionic clusters are shown to bind multiple SO₂ molecules. Theoretical analyses are in agreement with the experimental results, showing that the addition of more than one molecule is thermodynamically favorable. Larger clusters do not necessarily absorb more molecules, as different SO₂ binding motifs on these clusters are present. These results provide important insight for the potential use of these anionic clusters as SO₂ hunters.     

Extraction of Hetero Polyanions, P2W17O6110−, P2W18O626−, SiW11O398− by TBP

Hetero polyanions, namely, P₂W₁₇O₆₁ ^10–, P₂W₁₈O₆₂ ^6– and SiW₁₁O₃₉ ^8– were extracted by TBP/dodecane from HNO₃ or HCl solution, as H₁₀P₂W₁₇O₆₁ in the case of P₂W₁₇O₆₁ ^10–. The distribution ratio of P₂W₁₇O₆₁ ^10– depended on both H⁺ concentration and ionic strength of aqueous solution, and free-TBP concentration in organic solution. Experimental equation was established for predicting the distribution ratio of P₂W₁₇O₆₁ ^10– in nitrate system.     

X-ray Crystal Structure of (CNSSS)2(M)2 (M = AsF6 −, SbF6 −, Sb2F11 −)

The crystal structures of (CNSSS)₂(AsF₆)₂, (CNSSS)₂(SbF6)₂, and two phases of (CNSSS)₂(Sb₂F₁₁)₂ have been determined. The AsF₆ ^?, SbF₆ ^?, and α-Sb₂F₁₁ ^? salts crystallize as reddish-brown plates whereas the β-Sb₂F₁₁ ^? salt crystallizes as green rods. The dication ^ß+SSSNCCNSSS^+ß (1²⁺) is the same in all four structures and consists of two 7π rings linked by a sp²-sp² C-C bond (1.462 Å in 1 (AsF₆)₂). The packing in the four structures is similar with stacks of dications along the a-axis and alternating sheets of dications and anions lying in the bc-plane. The differences in the dication-dication contacts is reflected in the variable temperature magnetic data.     

Thermodynamics of Aqueous Diethylenetriaminepentaacetic Acid (DTPA) Systems: Apparent and Partial Molar Heat Capacities and Volumes of Aqueous H2DTPA3−, DTPA5−, CuDTPA3−, and Cu2DTPA− from 10 to 55°C

Apparent molar heat capacities and volumes have been determined for aqueous solutions of the mixed electrolytes Na₅DTPA + NaOH, Na₃CuDTPA + NaOH, and NaCu₂DTPA + NaOH, and the single electrolyte Na₃H₂DTPA (DTPA=diethylenetriaminepentaacetic acid) at temperatures from 10 to 55°C. The experimental results have been analyzed in terms of Young's rule with the Guggenheim form of the extended Debye–Hückel equation and the Pitzer ion-interaction model. These calculations led to standard partial molar heat capacities and volumes for the species H₂DTPA^3–(aq), DTPA^5–(aq), CuDTPA^3–(aq), and Cu₂DTPA^–(aq) at each temperature. The partial molar properties at 0.1 m ionic strength were also calculated. The standard partial molar properties were extrapolated to elevated temperatures with the revised Helgeson–Kirkham–Flowers (HKF) model. Values for the partial molar heat capacities from the HKF model have been combined with the literature data to estimate the ionization constants of H₂DTPA^3–(aq) and the formation constant of the CuDTPA^3–(aq) copper complex at temperatures up to 300°C.     

Adsorption of Cl−, Br−, and I− ions from 0.1 M solutions in methanol on Ga, (In-Ga), and (Tl-Ga) electrodes

Adsorption of Cl^?, Br^?, and I^? (Hal^?) ions from 0.1 M solutions in methanol (MeOH) is studied on the liquid renewable Ga, (In-Ga), and (Tl-Ga) electrodes by the methods of differential capacitance and jet electrode. It is shown that the adsorption parameters and the series of surface activity of halide ions in MeOH essentially depend on the metal nature. On the (In-Ga) and (Tl-Ga) electrodes, as well as on the Hg electrode, the surface activity of halide ions increases in the series: Cl^? < Br^? < I^?; on the Ga electrode, it varies in another series: Br^? < Cl^? < I^?. The data for the Ga/MeOH interface support the result, which was first obtained on the Ga/N-methyl formamide (N-MF) interface, that the effect of inversion of surface activity series can be observed not only in the aprotic solvents, but also in the protic solvents. The data, which were obtained in MeOH, are compared with the corresponding data, which were obtained in N-MF, dimethyl formamide (DMF), acetonitrile (AN), and water. For Ga, (In-Ga), and (Tl-Ga) electrodes, the adsorption of Hal^? varies in the series: H₂O < MeOH ≈ N-MF < DMF < AN. The data obtained in MeOH indicate that the energy of metal-Hal^? interaction (ΔG _M-Hal) increases in the series (Tl-Ga) < (In-Ga) < Ga as the electronic work function increases. This is in agreement with the data, which were obtained in other solvents, and is the evidence for the donor-acceptor nature of metal-Hal^? interaction, where the Hal^? ions are the donors of electron pair with respect to the metal.     

New Heteropolytungstates Incorporating Dioxouranium(VI). Derivatives of α-[SiW9O34]10−, α-[AsW9O33]9−, γ-[SiW10O36]8−, and [As4W40O140]28−

Reaction of uranium salts with several lacunary polyoxotungstate anions yields four new heteropolyanion assemblies in which the uranium atoms occupy pentagonal bipyramidal coordination polyhedra. Treatment of A,-[SiW₉O₃₄]^10– with UO₂(NO₃)₂ leads to Na₁₄[Na₂(UO₂)₂(SiW₉O₃₄)₂]38H₂O (1, Monoclinic, P2₁/c, a=16.5719(8) Å, b=14.1689(7) Å, c=21.2528(10) Å, =111.6670(10)°, V=4786.6(4) ų, Z=2) which proves to be isostructural with the analogous derivative of [PW₉O₃₄]^9– reported previously. Solutions of 1 exhibit the 5-line W-NMR spectrum expected for the structure of C _i point symmetry. The salt (NH₄)₁₇[(UO₂)₃(H₂O)₄As₃W₂₆O₉₄]16H₂O (2, Orthorhombic, Pnma, a=40.1747(2) Å, b=18.25840(10) Å, c=18.0817(2) Å, V=13263.4(2) ų, Z=4) was isolated in 64% yield from a reaction of UO₂(NO₃)₂ with B,-[AsW₉O₃₃]^9–. The structure of the anion in 2 has C _s symmetry and contains one -AsW₉O₃₃ and two novel -AsW₈O₃₀ units linked by the UO²⁺ ₂ groups; an additional WO₆ links the two AsW₈ fragments. Spectrophotometric titration of UCl₄ with the sodium salt of [As₄W₄₀O₁₄₀]^28– indicated the formation of a 4:1 U:As₄W₄₀ complex. During attempts to isolate a crystalline product from this reaction the uranium became oxidized and a guanidinium salt of [Na(UO₂)₃(OH)(H₂O)₆As₄W₄₀O₁₄₀(WO)]^18– (3, Orthorhombic, Fdd2, a=54.848(3) Å, b=80.809(4) Å, c=20.2874(2) Å, V=89919(7), Z=16) was isolated. The partially disordered structure of 3 shows the S₂ and adjacent sites of the lacunary As₄W₄₀ anion to be occupied by three UO₅ and one WO₅ polyhedra. A tetrameric assembly of -SiW₁₀ units linked by UO²⁺ ₂ groups occurs in [{M(OH₂)}₄(UO₂)₄(OH)₂(SiW₁₀O₃₆)₄]^22– (lithium salt, M=Na, 4a, tetragonal, P4₂/nmc, a=b=26.5285(2) Å, c=15.0463(2) Å, V=10589.0(2) ų, Z=2; sodium-potassium salt, M=K, 4b, orthorhombic, Fddd, a=24.180(5) Å, b=31.696(6) Å, c=58.012(12) Å, V=44460(15) ų, Z=8). Tungsten-183 NMR spectra show the slow transformation of the expected 5-line (1:1:1:1:1) spectrum of 4a to a new species giving a 6-line spectrum (2:2:2:1:2:1). The latter complex has not been successfully isolated.     

Die Anwendbarkeit von Ein-Zentrum-Wellenfunktionen mit sphärischer Symmetrie beiBH 4 −,CH 4 undNH 4 +

Zusammenfassung An den BeispielenBH ₄ ^–,CH ₄ undNH ₄ ⁺ wird die Anwendbarkeit von Ein-Zentrum-Wellenfunktionen mit sphärischer Symmetrie untersucht. Die Parameter der analytischen Wellenfunktionen (2 für ein 8-Elektronenmodell, 4 für ein 10-Elektronenmodell) werden für den Grundzustand der Moleküle teilweise neu durch Variationsrechnung ermittelt, zum anderen Teil aus der Literatur übernommen.Aus einer Vielzahl von möglichen Anwendungen werden die folgenden zur Berechnung und Diskussion ausgewählt: Diamagnetische Suszeptibilität, Elektronenpolarisierbarkeit und van der Waalssche Konstante, Bindungsmomente, Elektronenladung innerhalb einer Kugel, deren Oberfläche durch die Protonen geht, Normalfrequenzen, Chemische Verschiebung für den Zentralkern und die Protonen in 1. und 2. Näherungsordnung, Spin-Spin-Kopplung, Ionisierungspotentiale und Dissoziationsenergie vonCH ₄.Vergleichsmöglichkeiten ergeben sich innerhalb dieser Arbeit zwischen dem 8- und dem 10-Elektronenmodell. Ergebnisse anderer Autoren sowie experimentelle Werte werden mit den hier gewonnenen Resultaten in Beziehung gebracht.

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The use of one center wave functions with spherical symmetry is investigated for ,CH ₄ andNH ₄ ⁺. The parameters of the analytical wave functions (2 for a model with 8, 4 for another with 10 electrons) for the ground states are partially calculated by variation, partially taken from literature.The following applications are selected for calculation and discussion: diamagnetic susceptibility, electronic polarizability and van der Waals constant, bond moments, electronic charge inside a sphere through the protons, normal frequencies, chemical shift for the central nucleus and the protons in first and second order, spin-spin coupling, ionization potentials and dissociation energy ofCH ₄.The results of the eight and ten electron models are compared with each other and with theoretical and experimental values of other authors.

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Résumé L'utilisation des fonctions d'onde monocentriques à symétrie sphérique est discutée pourBH ₄ ^–,CH ₄ etNH ₄ ⁺. Les paramètres des fonctions d'onde analytiques (2 pour le modèle à 8, 4 pour celui à 10 électrons) pour l'état fondamental des molécules sont en partie calculés par variation, en partie pris dans la littérature.Les applications suivantes sont choisies pour être calculées et discutées: susceptibilité diamagnétique, polarisabilité électronique et constante de van der Waals, moments de liaison, charge électronique à l'intérieur d'une sphère passant par les protons, fréquences normales, chemical shift pour le noyau central et pour les protons en 1^ère et 2^ème approximation, couplage spin-spin, énergies d'ionisation et de dissociation pour CH₄.Les résultats des deux modèles (à 8 et à 10 électrons respectivement) sont comparés à des valeurs théoriques et expérimentales d'autres auteurs.

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Herrn Dr. F. J.Toole und dem National Research Council von Kanada sei für die Vermittlung und Gewährung eines Postdoctorate Fellowship herzlich gedankt. Herrn Professor W. D.Wasson stellte freundlicherweise den Elektronenrechner Royal Precision LGP-30 für die Minimisierung der Energiefunktionen zur Verfügung und war bei der Programmierung behilflich. Mein besonderer Dank gilt Herrn Dr. B.Kaiser für die rege Anteilnahme an dieser Arbeit, verbunden mit zahlreichen kritischen Diskussionen.     

Prediction of phase equilibrium for the aqueous systems Rb+, Cs+/Cl−, SO 4 – -H2O and K+, Cs+/Cl−, SO 4 2− -H2O at 25°C

The Pitzer ion-interaction extended by Harvic and Weare was applied to predict the solubility isotherms of reciprocal quaternary systems in which mixed crystals are formed. On the basis of data concerning the binary and ternary subsystems, the four components systems Rb⁺, Cs⁺/Cl^?, SO ₄ ^2? -H₂O, and K⁺, Cs⁺/Cl^?, SO ₄ ^2? -H₂O were investigated at 25°C.The results of calculation can be used to model salt crystallization during the concentration of brines.     

The conformational changes of 5SrRNA from lupin seeds in presence of ClO 4 − , NO 3 − , Br−, BF 4 − , SO 4 2− , Cl−, COO− anions by adiabatic scanning calorimetry

The results of calorimetric studies of 5SrRNA solutions isolated from lupin seeds in the pressence of the ClO ₄ ^? , NO ₃ ^? , Br ₄ ^? , SO ₄ ^2? , Cl^?, COO^? (maleic and fumaric acids) anions were reported. The plots of calorimetric curves, enthalpy of conformational changes of two state transitions were presented. Using the deconvolution method proposed by Freire and Biltonen the elementary transitions were distinguished and discussed.     

Transport of 125I−, 137Cs+ and 85Sr2+ in granitoidic rock and soil columns

Transport of ¹²⁵I^?, ¹³⁷Cs⁺ and ⁸⁵Sr²⁺ radionuclides in crushed granitoidic rocks and homogenized soils was studied. Two simple methods for calculation of breakthrough curves in flow column experiments with groundwater as transport medium have been described. The first method, so called non-linear approach, is derived on the assumption of a reversible non-linear sorption isotherm described with Freundlich equation, i.e., with non-constant distribution and retardation coefficients. The second method, so-called linear approach, is applied for reference only, and is based on the assumption of a reversible sorption characterized with linear sorption isotherm, i.e., with constant distribution and retardation coefficients. Both methods model the experimental breakthrough curves with the integrated form of the simple 1-D advection–dispersion equation (ADE) expressed analytically for pulse application of radiotracer to the liquid phase before entering the columns. The integrated form of the ADE equation was modified by the so-called peak position and peak height correction coefficients the advantage of which consists among others in the elimination of the influence of starting concentration. The comparison of both approaches has shown that fitting by means of non-linear approach has given rather reliable values of the transport parameters and calculated dependences, especially in a case of ¹³⁷Cs system characterized evidently with non-linear type of sorption isotherms. As for ¹²⁵I^?, the sorption capacity of all solid samples studied is nearly on the zero level and ¹²⁵I^? is practically not retarded, and from this point of view it behaves as non-interacting component. In addition, it was found that the modified ADE gives rather better results than the classical one.     

B,B′-Bis(borazyl)- und B,B′-Polyborazylenderivate

Zusammenfassung B-Chlorborazole reagieren mit Alkalimetallen unter Kondensation. Aus Monochlorborazolderivaten entstehen so B,B-Biborazyle, aus Dichlorborazolen B,B-Polyborazylene und aus Trichlorborazolen vernetzte Polymere von guter thermischer Beständigkeit.Mit 3 AbbildungenHerrn Prof. Dr.F. Halla zum 80. Geburtstag gewidmet.     

Kinetic and thermodynamic studies of aquation reactions in [RuL2(mac)]q+ complexes: [mac = 1,4,8,11-tetraazacyclotetradecane (cyclam) or 1,4,7,10-tetraazacyclododecane (cyclen); and L = Cl−, OH−, OH2]

Transition Metal Chemistry - We report here the synthesis, characterization and kinetic studies of [RuL2(mac)]n+ complexes [mac?=?1,4,8,11-tetraazacyclotetradecane (cyclam) or...