Separation of inorganic anions by reversed-phase ion-pair chromatography with direct UV detection

In this paper, a separation method of the inorganic anions including I^–, NO ₂ ^– , NO ₃ ^– , IO ₃ ^– and SCN^– on the reversed-phase ion-pair chromatography with direct UV detection has been developed, and the limits of detection of these inorganic anions were determined. The effects of the organic modifier volume fraction and concentration of the ion-pair reagent on the retention of inorganic anions were discussed.     

Determination of anions by non-suppressed ion chromatography using an amine column

Summary The Synchropak AX300 column has been used to separate a wide range of anions. A standard solution containing F^–, Cl^–, NO ₂ ^– , NO ₃ ^– , HPO ₄ ^2– , SO ₄ ^2– ions can be analysed in 8–14 minutes using a phthalate or phthalate/citrate eluent at pH 6–7. Addition of citrate to a phthalate eluent has a pronounced effect on the times of analysis. Detection by direction and indirect UV absorption enables the analysis of a wide range of anions. Application of the technique range from rain water to ash pond liquor analysis.     

1, 2-Dithiolium salts

A new method for the synthesis of 1, 2-dithiolium hydrogen sulfates by the oxidation of 1, 2-dithiole-3-thiones with hydrogen peroxide in acetic acid has been developed. From 4-(p-tolyl) 1, 2-dithiolium hydrogen sulfate a series of salts containing anions of inorganic, heteroorganic, and organic acids (Cl^–, Br^–, I^–, ClO ₄ ^– , CNS^–, VO ₃ ^– , HMoOO ₄ ^– , S₂O ₃ ^2– , S₂O ₈ ^2– , Cr₂O ₇ ^2– , Fe(CN) ₆ ^3– , Fe(CN) ₆ ^4– , B(C₆H₅) ₄ ^– , F₃CCOO^–, C₆H₂(NO₂)₃O^–) has been obtained. 4-(p-tolyl)-1, 2-dithiolium salts containing the anions NO ₂ ^– , NO ₃ ^– , ClO ₃ ^– , BrO ₃ ^– , SO ₃ ^2– , SO ₄ ^2– , S₂O ₅ ^2– and Cl₃CCOO^– dissolve in water and do not precipitate in double decomposition reactions. The reactions of 4-(p-tolyl)-1, 2-dithiolium hydrogen sulfate with sodium sulfite, disulfide, and hydrogen sulfide lead to the formation of bis[4-(p-tolyl)-1, 2-dithiol-3-yl] sulfide and disulfide and the sodium salt of 4-(p-tolyl-1, 2-dithiole-3-thiol, respectively. The reaction of 4-(p-tolyl)-1, 2-dithiolium hydrogen sulfate with solutions of salts of the alkali metals containing the anions of weak acids F^–, CNO^–, HCO ₃ ^– , CO ₃ ^2– , B₄O ₇ ^2– , HAsO ₄ ^2– , PO ₄ ^3– , CH₃COO^–, ClCH₂COO^–, etc.) forms bis[4-(p-tolyl)-1, 2-dithlol-3-yl] oxide. [8, Table 3].For part I, see [1].     

Peak parking technique for the simultaneous determination of anions and cations

An ion chromatography method is described for the simultaneous determination of anions (Cl^–, NO₃^–, and SO₄^2–) and cations (Na⁺, NH₄⁺, K⁺, Mg²⁺, and Ca²⁺) using a single pump, a single eluent and a single detector. An anion-exchange column modified with chondroitin sulfate C facilitated the elution of the above three anions using 5 mM tartaric acid as the eluent in isocratic mode, whereas the same eluent facilitated the separation of the above five cations on a commercially-available cation-exchange column. The separation columns were connected in series via two six-port switching valves, so the required cation-exchange or anion-exchange separation could be carried out by selecting the appropriate positions for the switching valves. The separations were completed in 30 min.     

Interaction of iron carbonyls with Lewis bases

The interaction of iron carbonyls Fe _n (CO) _m (wheren = 1,m = 5;n = 2,m = 9;n = 3,m = 12) with anionic Lewis bases (H^–, F^–, Cl^–, Br^– , I^–, CN^–, SCN^–, N₃ ^–, MeSO₃ ^–, MeCO₂ ^–, CF₃CO₂ ^–, S₂ ^–, CO₃ ^2–, and SO₄ ^2–) passes through two-stage redox-disproportionation. The first stage is the formation of an iron carbonyl-base complex, [Fe _n (CO) _m–1C(O)L]^–, and the second is a single-electron reduction of this complex by another molecule of the initial iron carbonyl, giving rise to Fe(l) and Fe(–l) derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 248–249, January, 1996.     

Complexes of tri- and tetra-protonated forms of 1,4,8,12-tetraazacyclopentadecane with chloride,nitrate, iodate,and sulfate ions in aqueous media: I. Formation constants,thermodynamic properties,and bonding mechanisms

Complexation stoichiometries and formation constants of tri- and tetra-protonated forms of 1,4,8,12-tetraazacyclopentadecane with NO ₃ ^– , Cl^–, IO ₃ ^– and SO ₄ ^2– ions are determined by pH potentiometric and¹³C NMR spectrometric measurements. Estimates of H and S are obtained from the values of the temperature dependent formation constants and acid dissociation constants. All four anions form only 1 : 1 complexes with the triprotonated amine species. NO ₃ ^– and Cl^– form 1 : 1 complexes only with the tetraprotonated amine, while IO ₃ ^– and SO ₄ ^2– form both 1 : 1 and 2 : 1 complexes. The complexation behavior is interpreted in terms of solvation and internal hydrogen bonding interactions.     

The character of interaction of organometallic derivatives of 4-nitrophenol and 4-nitrothiophenol with anions in different media

Interaction of R _n M-derivatives of 4-nitrophenol and thiophenol (R _n M= PhHG, PPh₃Au, Ph₃Sn, Ph₄Sb) with a set of inorganic and organic anions (Cl^–, Br^–, I^–, CN^–, [PhOCO]^–, [4-NO₂C₆H₄OCO]^–) was studied by IR and electronic spectroscopy in solvents with different polarities and coordinating properties (C₆H₆, CH₂Cl₂, DMSO). The dependence of the character of the interaction with the anions on the nature of the metal atom and heteroatom, the type of anions and the nature of the media was analyzed. Such interaction leads to ion-molecular complexes, and also to dissociation of the X-M bond (X = O, S, M = Au, Hg. Sb) with formation of the (4-NO₂C₆H₄X)^– anion even in weakly polar media. Only in the case of 4-NO₂C₆H₄OSnPh₃ does the reaction stop at the stage of complex formation. In other cases the role of complex formation with anions is less than with neutral coordinating reagents.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1838–1841, July, 1996.     

Simultane Bestimmung von einigen anorganischen und organischen Anionen durch ein ionenchromatographisches Drei-S?ulen-System

Zusammenfassung In der vorliegenden Arbeit wird erstmals eine neue Kombination von Ionen-Chromatographie und Ionenausschluß-Chromatographie vorgeschlagen, die dazu dient, Interferenzen bei der ionen-chromatographischen Fluoridbestimmung zu vermeiden und eine simultane Analyse einiger ausgewählter organischer Säuren zu ermöglichen. In dieser instrumentellen Anordnung werden die in der konventionellen Zwei-Säulen-Chromatographie (Ionenaustauschtrennsäule und Hohlfasersuppressor) nicht aufgetrennten Peaks schwacher Säuren an einer nachgeschaltenen Ionenausschlußsäule weiter aufgetrennt. Als Eluent dient die durch die Konvertierung des Carbonateluenten in der Suppressorreaktion entstandene Kohlensäure. Dieses System gestattet die automatische und simultane Bestimmung von Anionen schwacher und starker Säuren, wie F^–, HCOO^–, CH₃COO^–, Cl^–, NO ₂ ^– , HPO ₄ ^2– , Br^–, NO ₃ ^– , und SO ₄ ^2– , sowie eine gleichzeitige Abtrennung des carbonatischen Matrixpeaks. Die Optimierung der Analysenparameter sowie die analytischen Kenngrößen werden beschrieben und anhand eines Anwendungsbeispiels aus der Aerosolanalytik illustriert.

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Simultaneous determination of some inorganic and organic anions by means of an ion-chromatographic triple column system

Summary A new combination of ion chromatography with ion-exclusion partition-chromatography is suggested in order to overcome the interferences with the fluoride peak eluting at first and to render possible a simultaneous determination of certain organic acids. The principle is the fact that not yet resolved peaks consisting of weak acids are separated on an ion-exclusion column located after the fiber suppressor in the conventional dual-column anion-chromatography (ion-exchange column and suppressor column). The carbonic acid originating from the conversion of the carbonate eluent in the suppressor reaction is acting as eluent. Using the described set-up a simultaneous determination of F^–, HCOO^–, CH₃COO^–, Cl^–, NO ₂ ^– , HPO ₄ ^2– , Br^–, NO ₃ ^– , and SO ₄ ^2– is possible. In consequence, disturbing carbonate matrix peaks are separated. In the present paper the optimization and analytical characteristics are described and an example of application for the analysis of atmospheric aerosols is given.

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Vortrag anläßlich des Symposiums Anorganische Anionenanalytik, Regensburg, 19.–21. 9. 1984     

Coordination chemistry of poly(1-pyrazolyl)alkanes,part IV. Copper(II) complexes of bis- and tris-(1-pyrazolyl)methane

Summary The reactions of some copper(II) salts with bis(1-pyrazolyl)methane, H₂Cbpz, bis(3,5-dimethylpyrazolyl)methane, H₂Cbdmpz, and tris(1-pyrazolyl)methane, HCtpz give the following solid complexes: CuLX₂ · nH₂O (L=H₂Cbpz, H₂Cbdmpz or HCtpz; X=Cl^–, Br^–, NO ₃ ^– , OAc^–, or 1/2 SO ₄ ^2– and n=0, 1, 3 or 5) and CuL₂X₂ · nH₂O (L=HCtpz, X= C^–, Br^–, NO ₃ ^– or ClO ₄ ^– and n=0 or 2). The complexes have been characterised by elemental analysis, visible and i.r. spectral measurements.The reactions of Cu(HCtpz)X₂ · nH₂O (X=Cl^– or Br^–) with acetylacetonate (acac^–), dialkyldithiocarbamate (S₂CNMe ₂ ^– , S₂CNEt ₂ ^– ) or poly(1-pyrazolyl)borate (H₂Bbpz^–, HBtpz^–) in aqueous solutions lead to the displacement of HCtpz and the subsequent formation of neutral [Cu(acac)₂], [Cu(S₂CNR₂)₂], [Cu(H₂Bbpz)₂] and Cu(HBtpz)₂ while the reaction with oxalate ion, C₂O ₄ ^2– yields a stable neutral solid compound, [Cu(HCtpz)(C₂O₄)].     

Electronic structure and reactivity of PO 43? , P2O 74? phosphate and SO 42? , S2O 72? sulfate anions

Group-theoretical analysis and molecular orbital methods were used to obtain (in analytical form) the electronic structure and reactivity of the PO ₄ ³⁻ , SO ₄ ²⁻ and P₂O ₇ ⁴⁻ , S₂O ₇ ²⁻ anions. The reactivity of the anions is dictated by the availability of lone electron pairs on the top quasidegenerate MOs in the form of linear combinations of group orbitals from atomic orbitals (AOs) of peripheral oxygen atoms for PO ₄ ³⁻ , SO ₄ ²⁻ and the central (bridging) atom for P₂O ₇ ⁴⁻ , S₂O ₇ ²⁻ . These electron pairs are responsible for the donor-acceptor interactions during complexation, clustering, and other (addition, substitution, etc.) reactions. Original Russian Text Copyright ? 2005 V. A. Zasukha, A. P. Shpak, V. V. Trachevskii, and E. V. Urubkova __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 3, pp. 405–415, May–June, 2005.     

Single-run ion chromatographic separation of inorganic and low-molecular-mass organic anions under isocratic elution: Application to environmental samples

For the isocratic ion chromatography (IC) separation of low-molecular-mass organic acids and inorganic anions three different anion-exchange columns were studied: IonPac AS14 (9 μm particle size), Allsep A-2 (7 μm particle size), and IC SI-50 4E (5 μm particle size). A complete baseline separation for all analyzed anions (i.e., F⁻, acetate, formate, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, HPO₄²⁻ and SO₄²⁻) in one analytical cycle of shorter than 17 min was achieved on the IC SI-50 4E column, using an eluent mixture of 3.2 mM Na₂CO₃ and 1.0 mM NaHCO₃ with a flow rate of 1.0 mL min⁻¹. On the IonPac AS14 column, it was possible to separate acetate from inorganic anions in one run (i.e., less than 9 min), but not formate, under the following conditions: 3.5 mM Na₂CO₃ plus 1.0 mM NaHCO₃ with a flow rate of 1.2 mL min⁻¹. Therefore, it was necessary to adapt a second run with a 2.0 mM Na₂B₄O₇ solution as an eluent under a flow rate of 0.8 mL min⁻¹ for the separation of organic ions, which considerably enlarged the analysis time. For the Allsep A-2 column, using an eluent mixture of 1.2 mM Na₂CO₃ plus 1.5 mM NaHCO₃ with a flow rate of 1.6 mL min⁻¹, it was possible to separate almost all anions in one run within 25 min, except the fluoride-acetate critical pair. A Certified Multianion Standard Solution PRIMUS for IC was used for the validation of the analytical methods. The lowest RSDs (less than 1%) and the best LODs (0.02, 0.2, 0.16, 0.11, 0.06, 0.05, 0.04, 0.14 and 0.09 mg L⁻¹ for F⁻, Ac⁻, For⁻, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, HPO₄²⁻ and SO₄²⁻, respectively) were achieved using the IC SI-50 4E column. This column was applied for the separation of concerned ions in environmental precipitation samples such as snow, hail and rainwater.     

Determination of sulfur contents of SO3, S2O3 and S based on the electrocatalytic interaction with homogeneous mediator tris(2,2'-bipyridyl)Ru(II)

A sensitive voltammetric method has been developed for the determination of total or single species of sulfur anions containing sulfide, sulfite and thiosulfate. The method is based on the catalytic effect of tris(2,2'-bipyridyl)Ruthenium(II) (Ru(bpy)₂^+ 2) as a homogeneous mediator on the oxidation of those anions at the surface of a glassy carbon electrode. A reversible redox couple of Ru(II)/Ru(III) were observed as a solute in aqueous solution. Cyclic voltammetry study showed that the catalytic current of the system depends on the concentration of the anions. Optimum pH values for voltammetric determination of sulfite, thiosulfate and sulfide has been found to be 5.6, 10.0 and 10.0, respectively. Under the optimized conditions the calibration curves have been obtained linear in the concentration ranges of 0.8–500.0, 0.4–1000.0 and 0.5–5000.0 µmol L^− 1 of SO₃²⁻, S₂O₃²⁻ and S²⁻, respectively. The detection limits have been calculated to be 0.40, 0.17 and 0.33 µmol L^− 1 for SO₃²⁻, S₂O₃²⁻ and S²⁻, respectively. The diffusion coefficients of sulfite and thiosulfate have been estimated using chronoamperometry. The chronoamperometric method also has been used to determine the catalytic rate constant for catalytic reaction of the Ru(bpy)₂^+ 2 with sulfite and thiosulfate. Finally the proposed method has been used for the determination of total sulfur contents in real samples of water and wastewater. Moreover the sulfite content in sugar and sulfur dioxide in air has been determined with satisfactory results.     

Electrochemical study of isopoly and heteropoly anion transfer across the water | nitrobenzene interface. Part II. Vanadium-containing heteropolytungstate anions

The electrochemical transfer behaviour of vanadium-containing heteropolytungstate anions [PW_12−xV_xO₄₀]^(3+x)− (x = 1−4) across the water | nitrobenzene interface has been investigated by cyclic voltammetry and chronopotentiometry with cyclic linear current scanning. The transfer of PW₁₁V₁O⁴⁻₄₀, HPW₁₀V₂O⁴⁻₄₀, H₂PW₁₀V₂O³⁻₄₀, H₃PW₉V₃O³⁻₄₀ and H₄PW₈V₄O³⁻₄₀ across the water | nitrobenzene interface can be observed within the potential window. The effects were observed of pH in the water phase on the transfer behaviour and the formation of vanadium-containing heteropolytungstate anions in solution. Heteropolytungstate anions become more stable due to their involving the vanadium atom. The degree of protonation and the dissociation constant of the trivalent vanadium-containing heteropolytungstate anion of protonation increase with increasing vanadium content. The transfer processes are diffusion-controlled. The standard transfer potential, the standard Gibbs energy and the dissociation constant for vanadium-containing heteropolytungstate anions have been obtained and the transfer mechanisms are discussed.     

Extraction characteristics of pertechnetate with tetraphenylarsonium in the presence of chloride,nitrate and perchlorate anions

Selected extraction systems of TcO ₄ ^– –(H,Na)A–H₂O/R(TcO₄,A)–CHCl₃, C₆H₅NO₂ type, where A=Cl^–, NO ₃ ^– , ClO ₄ ^– , R=(C₆H₅)₄As⁺, were studied. The solvent extraction of sub- and super-stoichiometric ratio of TcR was performed. The solubility of (C₆H₅)₄AsTcO₄ in water, chloroform and nitrobenzene were determined too. The results of the extractions are presented in the form of TcO ₄ ^– distribution dependencies on the phase composition and the extraction constants of individual TcO ₄ ^– , Cl^–, NO ₃ ^– , ClO ₄ ^– anions and TcO ₄ ^– -Cl^–, TcO ₄ ^– –NO ₃ ^– , TcO ₄ ^– –ClO ₄ ^– ion pairs.     

Natural abundance C REDOR coupled to a singly N-labeled nucleus: simultaneous determination of interatomic distances in crystalline ammonium [N] -glutamate monohydrate

REDOR technique was applied to natural abundance ¹³C nuclei coupled to a singly labeled ¹⁵N nucleus to determine the ¹³C, ¹⁵N interatomic distances simultaneously in crystalline ammonium [¹⁵N] -glutamate monohydrate (1). Consequently, the interatomic C–N distances between ¹⁵N and ¹³C=O, ¹³C_α, ¹³C_β, ¹³C_γ, and ¹³C_δ carbon nuclei for 1 were determined with a precision of ±0.15 Å, after the experimental conditions such as the location of samples in the rotor, length of π pulse etc. were carefully optimized. ¹³C-REDOR factors for three spin system, (ΔS/S₀)_CN1N2, and the sum of two isolated 2-spin system, (ΔS/S₀)^*=(ΔS/S₀)_CN1+(ΔS/S₀)_CN2, were further evaluated by the REDOR measurements on isotopically diluted 1 in a controlled manner. Subsequently, the intra- and intermolecular C–N distances were separated by searching the minima in the contour map of root mean square deviation (RMSD) between the theoretically and experimentally obtained (ΔS/S₀)^* values against two interatomic distances, r_C–N1 and r_C–N2. When the intramolecular C–N distance (r_C–N1) of the particular carbon nucleus is substantially shorter than the intermolecular one (r_C–N2), C–N distances within a single molecule were obtained with an accuracy of ±0.06 Å as in the cases of C=O, C_α and C_β carbon nuclei. C–N distances between the molecule in question and the nearest neighboring molecules can be also obtained, although accuracy was lower. On the contrary, it was difficult to determine the interatomic distances in the same molecule when the intermolecular dipolar contribution is larger than the intramolecular one as in the case of C_δ carbon nucleus.     

Synthesis,Structures, and Properties of Crystalline Salts with Radical Anions of Metal‐Containing and Metal‐Free Phthalocyanines

Radical anion salts of metal‐containing and metal‐free phthalocyanines [MPc(3?)]^.?, where M=Cu^II, Ni^II, H₂, Sn^II, Pb^II, Ti^IVO, and V^IVO ( 1 – 10 ) with tetraalkylammonium cations have been obtained as single crystals by phthalocyanine reduction with sodium fluorenone ketyl. Their formation is accompanied by the Pc ligand reduction and affects the molecular structure of metal phthalocyanine radical anions as well as their optical and magnetic properties. Radical anions are characterized by the alternation of short and long C?N_imine bonds in the Pc ligand owing to the disruption of its aromaticity. Salts 1 – 10 show new bands at 833–1041 nm in the NIR range, whereas the Q‐ and Soret bands are blue‐shifted by 0.13–0.25 eV (38‐92 nm) and 0.04–0.07 eV (4–13 nm), respectively. Radical anions with Ni^II, Sn^II, Pb^II, and Ti^IVO have S=1/2 spin state, whereas [Cu^IIPc(3?)]^.? and [V^IVOPc(3?)]^.? containing paramagnetic Cu^II and V^IVO have two S=1/2 spins per radical anion. Central metal atoms strongly affect EPR spectra of phthalocyanine radical anions. Instead of narrow EPR signals characteristic of metal‐free phthalocyanine radical anions [H₂Pc(3?)]^.? (linewidth of 0.08–0.24 mT), broad EPR signals are manifested (linewidth of 2–70 mT) with g‐factors and linewidths that are strongly temperature‐dependent. Salt 11 containing the [Na^IPc(2?)]^? anions as well as previously studied [Fe^IPc(2?)]^? and [Co^IPc(2?)]^? anions that are formed without reduction of the Pc ligand do not show changes in molecular structure or optical and magnetic properties characteristic of [MPc(3?)]^.? in 1 – 10 .     

Coadsorption of Tetraalkylammonium Cations and Halide Anions on the Uncharged Surface of Mercury Electrode

The data on coadsorption of tetraethylammonium (Et₄N⁺), tetrapropylammonium (Pr₄N⁺), and tetrabutylammonium (Bu₄N⁺) cations with Cl^–, Br^–, and I^– anions on an uncharged mercury electrode are compared with the models of coadsorption in a common monolayer and two parallel layers. The second model is shown to be in best agreement with experimental isotherms. However, the least discrepancy between calculations and experimental results is obtained when coadsorption of mentioned cations and anions is described by the Frumkin isotherm for neutral molecules with certain effective adsorption parameters.     

The alkali metal cation effect on the surface-enhanced Raman spectra of phosphate anions adsorbed at silver electrodes

The interaction of adsorbed phosphate anions with alkali metal cations at the Ag|aqueous solution interface has been investigated by surface-enhanced Raman spectroscopy (SERS). Formation of ion pairs at the interface was evident from the cation-induced perturbations in the SER spectra of anions. The frequency of the external vibration, silver–oxygen (Ag---O′), was not sensitive to the nature of cation, while the relative intensity of this mode was cation-dependent and was explored as a sensitive probe for the monitoring of coadsorption of ions at the interface. From the internal phosphate vibrations, both asymmetric modes, δ_as(PO) and ν_as(PO), were found to be the most sensitive to the nature of the cation. At a relatively positive potential (0.00 V vs. Ag | AgCl) the spectral parameters for the Cs⁺ and K⁺ cations were very similar indicating the same bonding type with anions. A more inhomogeneous chemical environment for the phosphate oxygen atoms was detected in the case of Na⁺ and Li⁺ cations. An increase in ν_as(PO) frequency by ca. 10 cm⁻¹ was the characteristic spectral signature for the interaction of phosphates with Li⁺. The formation of water-shared ion pairs at the interface was suggested based on the absence of splitting in the ν_as(PO) mode and the previously observed frequency sensitivity of this band to solvent H₂O substitution by D₂O. At negative potential (−0.80 V), a stabilization effect of Cs⁺ on the phosphate adlayer was detected based on the twofold increase in intensity of the ν(Ag---O′) mode compared with Li⁺. Splitting of the ν_as(PO) mode suggested the contact interaction of anions with specifically adsorbed Cs⁺ cations.     

Preparation,spectroscopic and structural analysis of uranium-arabinose complexes

The reaction betweenL-arabinose and hydrated uranyl salts has been investigated in aqueous solution and the solid complexes of the type UO₂(L-arabinose)X ₂ · 2 H₂O, whereX=Cl^–, Br^–, and NO ₃ ^– , have been isolated and characterized. Due to the marked similarities with those of the structurally known Ca(L-arabinose)X ₂ · 4 H₂O and Mg(L-arabinose)X ₂ · 4 H₂O (X=Cl^– or Br^–) compounds, the UO ₂ ²⁺ ion binds obviously to twoL-arabinose moieties, through O1, O5 of the first and O3, O4 of the second molecule resulting into a six-coordinated geometry around the uranium ion with no direct U-X (X=Cl^–, Br^– or NO ₃ ^– ) interaction. The intermolecular hydrogen bonding network of the freeL-arabinose is rearranged upon uranium interaction. The -anomer configuration is predominant in the freeL-arabinose, whereas the -anomer conformation is preferred in the uranium complexes.

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Darstellung, spektroskopische und Strukturanalyse von Uran-Arabinose Komplexen

Zusammenfassung Es wurde die Reaktion zwischenL-Arabinose und hydratisierten Uranylsalzen in wäßriger Lösung untersucht und kristalline Komplexe des Typs UO₂(L-Arabinose)X ₂ · 2 H₂O mitX=Cl^–, Br^– und NO ₃ ^– isoliert und charakterisiert. Wie aus markanten Ähnlichkeiten der Komplexe mit den bekannten Verbindungen Ca(L-Arabinose)X ₂ · 4 H₂O und Mg(L-Arabinose)X ₂ · 4 H₂O (X=Cl^– oder Br^–) abzuleiten ist, bindet das UO ₂ ²⁺ -Ion mit zweiL-Arabinose Einheiten, wobei sich durch die O1,O5-Koordination des ersten und die O3,O4-Koordination des zweiten Moleküls eine sechs-koordinierte Geometrie um das Uranylion [ohne direkte U-X (X=Cl^–, Br^– oder NO ₃ ^– ) Wechselwirkung] ausbildet. Die intermolekularen Wasserstoffbrücken zeigen nach der Wechselwirkung mit dem Uranylion eine Umgruppierung. In der freienL-Arabinose ist das -Anomere vorherrschend, in den Urankomplexen hingegen das -Anomere.