Number Of Chloride Ions Research Articles

Tuning the Ground- and Excited-State Redox Potentials of Octahedral Hexanuclear Rhenium(III) Complexes by the Combination of Terminal Halide and N-Heteroaromatic Ligands.

The present study reports that the ground- and excited-state Re6(23e)/Re6(24e) redox potentials of an octahedral hexanuclear rhenium(III) complex can be controlled by systematically changing the number and type of the N-heteroaromatic ligand (L) and the number of chloride ions at the six terminal positions. Photoirradiation of [Re6(μ3-S)8Cl6]4– with an excess amount of L afforded a mono-L-substituted hexanuclear rhenium(III) complex, [Re6(μ3-S)8Cl5(L)]3– (L = 4-dimethylaminopyridine (dmap), 3,5-lutidine (lut), 4-methylpyridine (mpy), pyridine (py), 4,4′-bipyridine (bpy), 4-cyanopyridine (cpy), and pyrazine (pz)). The bis- and tris-lut-substituted complexes, trans- and cis-[Re6(μ3-S)8Cl4(lut)2]2– and mer-[Re6(μ3-S)8Cl3(lut)3]−, were synthesized by the reaction of [Re6(μ3-S)8Cl6]3– with an excess amount of lut in refluxed N,N-dimethylformamide. The mono-L-substituted complexes showed one-electron redox processes assignable to E1/2[Re6(23e)/Re6(24e)] = 0.49–0.58 V versus Ag/AgCl. The ground-state oxidation potentials were linearly correlated with the pKa of the N-heteroaromatic ligand [pKa(L)], the 1H NMR chemical shift of the ortho proton on the coordinating ligand, and the Hammett constant (σ) of the pyridyl-ligand substituent. The series of [Re6(μ3-S)8X6–n(L)n]n−4 complexes (n = 0, X = Cl, Br, I, or NCS; n = 1–3, X = Cl) showed a linear correlation with the sum of the Lever electrochemical parameters at the six terminal ligands (ΣEL). The cyclic voltammograms of the mono-L-substituted complexes (L = bpy, cpy, and pz) showed one-electron redox waves assignable to E1/2(L0/L–) = −1.28 to −1.48 V versus Ag/AgCl. Two types of photoluminescences were observed for the complexes, originating from the cluster core-centered excited triplet state (3CC) for L = dmap, lut, mpy, and py and from the metal-to-ligand charge-transfer excited triplet state (3MLCT) for L = bpy, cpy, and pz. The complexes with the 3CC character exhibited emission features and photophysical properties similar to those of ordinary hexanuclear rhenium complexes. The emission maximum wavelength of the complexes with 3MLCT shifted to the longer wavelength in the order L = 4-phenylpyridine (ppy), bpy, pz, and cpy, which agreed with the difference between E1/2[Re6(23e)/Re6(24e)] and E1/2(L0/L–). The calculated oxidation potential of the excited hexanuclear rhenium complex with the 3CC character was linearly correlated with pKa(L), σ, and ΣEL. The ground- and excited-state oxidation potentials were finely tuned by the combination of halide and L ligands at the terminal positions.

Тенденция изменения качества воды главного Ширванского коллектора за многолетний период

The article examines the tendency of changes in the hydrochemical regime of the water of the Main Shirvan collector over a long period of time and the suitability of the collector water for irrigation. Continuous laboratory analyzes performed between 2004 and 2019 were compared to 1986. According to experimental data, it was determined that the hydrochemical regime of the collector water is gradually improving, and the salt content is decreasing. The degree of mineralization of the collector water decreased by 2.3 times, the total hardness by 2.2 times, the number of chloride ions by 10.5 times, the number of calcium ions by 1.3 times, the number of magnesium ions by 2.8 times, the total number of cations sodium and potassium decreased by 3.9 times. For 2004–2019 biochemical oxygen consumption in collector water increased 7.9 times, chemical oxygen demand increased 7.5 times, and the number of suspended particles increased 9 times. The amount of iron ions in water decreased by 2 times, while the amount of aluminum and zinc did not change. The suitability of collector water for irrigation was determined according to 7 internationally accepted assessment criteria. Collector water is considered suitable for irrigation in accordance with 6 assessment criteria — the degree of salinity, irrigation coefficient, sodium sorption coefficient, potential salinity, water alkalinity index and percentage of sodium, as well as 1 criterion not suitable for irrigation — the percentage of magnesium. Collector water can be used to irrigate crops.

A laccase Gl-LAC-4 purified from white-rot fungus Ganoderma lucidum had a strong ability to degrade and detoxify the alkylphenol pollutants 4-n-octylphenol and 2-phenylphenol

In this study, the ability of laccase Gl-LAC-4, purified from Ganoderma lucidum, to degrade and detoxify two representative alkylphenol pollutants, 4-n-octylphenol and 2-phenylphenol, was systematically studied. Gl-LAC-4 laccase had a very strong ability to degrade high concentrations of 4-n-octylphenol, 2-phenylphenol, and alkylphenol mixtures. The degradation speed of Gl-LAC-4 toward 2-phenylphenol was very fast. Gl-LAC-4 displayed strong tolerance for a variety of metal salts and organic solvents in the degradation of alkylphenols. Gl-LAC-4 showed strong tolerance for high concentrations of various metal salts, such as MgSO4, MnSO4, Na2SO4, CuSO4, ZnSO4, CdSO4, and K2SO4, in the degradation of 4-n-octylphenol and 2-phenylphenol.In the case of the same metal cation, the inhibitory effect of the metal salt with Cl− as the anion on the degradation of 4-n-octylphenol and 2-phenylphenol by laccase was stronger than that of the metal salt with SO42− as the anion. An increase in the number of chloride ions caused a greater inhibitory effect on alkylphenol degradation by laccase. Gl-LAC-4 exhibited strong tolerance for glycerol, ethylene glycol, butanediol, propylene glycol, and organic solvent mixtures in the degradation of alkylphenols. Gl-LAC-4 treatment significantly reduced or eliminated the phytotoxicity of 4-n-octylphenol and 2-phenylphenol.

An electrospray ionization mass spectrometric study of beryllium chloride solutions and complexes with crown ether and cryptand macrocyclic ligands

The speciation of beryllium chloride solutions has been investigated using electrospray ionization mass spectrometry in both positive and negative ion modes. The majority of observed species were mixed beryllium-chlorido-oxido-hydroxido species, with the degree of hydration of the observed ions depending on the number of chloride ions. The observed species contain between 1 and 6 Be ions. The interactions of BeCl2 with a selection of crown ether ligands and cryptand[2.2.2] were also investigated using ESI MS. These ligands have low affinity for Be2+, instead the observed ions are dominated by species formed from adventitious Na+ or K+ ions. The crown ether 12-crown-4 showed the most complex spectra, as a result of greater interactions with Be2+, as evidenced by observed ions such as [BeX(12-crown-4)]+ (X = Cl or OH). The interactions of crown ethers with beryllium ions (as well as coordinated Cl- or OH- ancillary ligands) were investigated using Density Functional Theory [B3LYP/6-311++G(dp)], where it was shown that the species [BeX(crown ether)]+ (X = Cl or OH) are considerably more stable than [Be(crown ether)]2+ species, with 12-crown-4 forming the most stable complex. The combination of ESI MS and DFT investigations indicates that full encapsulation of the Be2+ by crown ethers is unfavorable, and coordination with an accompanying hydroxide or chloride is preferred.

Chloride Ion Batteries Based on Metal Oxychloride/Metal Electrode Systems

Rechargeable batteries are receiving particular attention in diverse areas of portable electronic devices, electric vehicles (EV) and other energy storage systems. We previously reported the proof-of-principle of a new concept of rechargeable batteries based on chloride shuttle, i.e., chloride ion batteries, by means of charge and discharge test, cyclic voltammetry, X-ray diffraction, and X-ray photoelectron spectroscopy. This battery system includes a metal chloride/metal electrochemical couple and an electrolyte composed of binary ionic liquids allowing chloride ion transfer at room temperature. The reactions for this battery could be expressed as:Cathode: McCln ↔ Mc + nCl- (1)Anode: Ma + mCl- ↔ MaClm (2)Cell: mMcCln + nMa ↔ mMc + nMaClm (3)where Mc is the metal element in the cathode, Mais the metal used in the anode, and m or n is the number of chloride ions. Lithium may be included as reaction partner but not necessarily, depending on the choice of the electrochemical couple. The concept has the advantage of a broad variety of potential electrochemical couples with high theoretical energy density up to values of 2500 Wh/L, which is close to the theoretical energy density of the Li/S battery. Moreover, chloride ion batteries can be built from abundant material resources, due to the lack of Li they can be safer, and have environmentally friendly features. These attributes could make the chloride ion battery a potential alternative in the field of rechargeable batteries. A key challenge is to suppress the dissolution of cathode materials mainly composed of transition metal chlorides, which are Lewis acid and can react with a Lewis base containing chloride ion, resulting in the formation of soluble complex ions. Metal oxychlorides are regarded to be stable in the ionic liquid electrolyte of chloride ion batteries. Moreover, metal oxychloride/metal systems could also show a large Gibbs free energy change yielding a high electromotoric force (EMF) during the chloride ion transfer. For instance, the VOCl2/Li electrochemical couple possesses an EMF of 2.78 V and a theoretical energy density of 984.2 Wh g-1. The overall reaction for this battery could be expressed as:mMcOCln + nMa ↔ mMcO + nMaClm (4) The electrochemical performance and the reaction mechanisms of the BiOCl and FeOCl cathode were investigated, where Li was used as anode. In first experiments, the BiOCl cathode showed a reversible capacity of about 60% of the theoretical capacity, which is mainly derived from the conversion reaction. An intercalation reaction during cycling is also observed. In the discharge stage, the BiOCl loses the chloride ion and transforms to Bi metal and amorphous Bi2O3, with a considerable morphology change from needle-like to granular. The return of chloride ion during charge results in the recovery of BiOCl phase at the cathode side. The FeOCl cathode also showed reversible reactions based on the chloride shuttle. A discharge capacity of 158 mAh g-1 was measured in the first cycle and a stable discharge capacity of 60 mAh g-1after 30 cycles. These results suggest that metal oxychlorides are a promising cathode materials for chloride ion batteries. A key advantage of chloride ion batteries is the use abundant materials such as Mg, La, Ca and Na as anode materials. We found that Mg is promising as anode material based on our new results. For instance, the BiOCl cathode (BiOCl/Mg) showed a discharge capacity of 70 mAh g-1, i.e., 68% of theoretical capacity at the second cycle. The electrochemical performance of metal oxychloride/Mg systems was investigated including single electron or multi-electron cathode. Moreover, a new approach was tested using multi-electron metal oxychloride cathode and Mg/MgCl2 composite anode.

Cosolvent or Antisolvent? A Molecular View of the Interface between Ionic Liquids and Cellulose upon Addition of Another Molecular Solvent

Ionic liquids (ILs) are promising nonderivatizing solvents for the dissolution of cellulose and lignin in biomass pretreatment processes, which are, however, retarded by sluggish dynamics. Recent investigations showed that cosolvents such as dimethyl sulfoxide (DMSO) can accelerate the dissolution dramatically. On the other hand, water is used as a common antisolvent to regenerate cellulose from solutions. To understand the co-/antisolvent effects in dissolving cellulose by ILs, we performed molecular dynamics simulations of the interfaces between an Iβ cellulose crystal and different solvent systems, including ILs, DMSO, water, and mixed solvent systems. The density profiles and pair energy distributions (PEDs) show that the anions interact much more strongly with the cellulose surface than the cations, which is responsible for the dissolution of cellulose. It was found that the number of chloride ions in contact with cellulose does not cause the co-/antisolvent effect. In contrast, the cellulose-chloride PEDs are sensitive to the addition of molecular solvents, such as DMSO and water. Detailed analyses show that multiple hydrogen-bond (HB) patterns are formed between chloride and the hydroxyl groups of cellulose that are noticeably changed in the presence of DMSO or water. A combined analyses of both the PEDs and HB patterns can provide valuable information about the enhancement of cellulose dissolution. The simulation results in this work present useful knowledge for the design of solvent systems for dissolving cellulose or other types of biomass.

Electroless deposition of gold into poly-3,4-ethylenedioxythiophene films and their characterization performed in chloride-containing solutions

Au-containing polymer films were obtained by electroless deposition of gold from diluted solutions of HAuCl4 into preliminarily reduced poly-3,4-ethylenedioxythiophene (PEDOT) films. Structural peculiarities of such pristine and composite films were characterized by scanning and transmission electron microscopy methods. It was established that the gold clusters forming under such deposition appear on the outer surface of polymer films and their pores. The clusters’ sizes ranged between 30 and 100 nm depending on the time of exposition of a PEDOT film in solutions of Au(III) ions and the concentration of these ions. It was also observed that in contrast to pristine PEDOT films, cyclic voltammograms (CVs) of composite films in the presence of chloride ions show additional redox peaks resulting from oxidation of gold with formation of an insoluble product and followed by the product reduction under reversal of the potential scan direction. As a result of parallel electrochemical quartz crystal microbalance (EQCM) and CV measurements, it was also established that the number of chloride ions per one transferring electron in the gold oxidation process is near to unity. To elucidate the oxidation degree of gold in the presence of chloride ions, a special procedure of changing the electrode potential was used. It consisted of clamping the high anodic potential in the region of gold oxidation (0.97 V, Ag/AgCl) and subsequent gradual decrease of the electrode potential with a constant scan rate. Under these conditions, it was possible to completely oxidize all the gold particles containing in a composite film and find out the maximum amount of electricity consumed for the product particles’ reduction. A comparison between such data and the results obtained in EQCM determinations of the gold content in the same film led to the conclusion that the oxidation state of gold in the complexes formed is Au(III). The effects of chloride ion concentration and scan rate of the electrode potential on current responses of PEDOT–Au films were investigated. Some primary conclusions on the kinetics of the studied processes are made.

The structure and stability of aqueous rare-earth elements in hydrothermal fluids: New results on neodymium(III) aqua and chloroaqua complexes in aqueous solutions to 500 °C and 520 MPa

X-ray absorption spectroscopy (XAS) measurements were made at the Nd L 3-edge on neodymium(III) aqua and chloroaqua complexes in low pH aqueous solutions from 25 to 500 °C and up to 520 MPa. Analysis of the extended X-ray absorption fine structure of the XAS spectra measured from a 0.07 m Nd/0.16 m HNO 3 aqueous solution reveals a contraction of the Nd-O distance of the Nd 3+ aqua ion at a uniform rate of ~ 0.013 Å/100 °C and a uniform reduction of the number of coordinated H 2O molecules from 10.0 ± 0.9 to 7.4 ± 0.9 over the range from 25 to 500 °C and up to 370 MPa. The rate of reduction of the first-shell water molecules with temperature for Nd 3+ (26%) is intermediate between the rate for the Gd 3+ aqua ion (22% from 25 to 500 °C) and the rates for the Eu 3+ (29% from 25 to 400 °C) and the Yb 3+ aqua ions (42% from 25 to 500 °C) indicating an intermediate stability of the Nd 3+ aqua ion consistent with the tetrad effect. Nd L 3-edge XAS measurements of 0.05 m NdCl 3 aqueous solution at 25 to 500 °C and up to 520 MPa show that stepwise inner-sphere complexes most likely of the type Nd(H 2O) δ − n Cl n +3 − n occur in the solution at elevated temperatures, where δ ≈ 9 at 150 °C decreasing to ~ 6 at 500 °C and the number of chloride ions ( n) of the chloroaqua complexes increases uniformly with temperature from 1.2 ± 0.2 to 2.0 ± 0.2 in the solution upon increase of temperature from 150 to 500 °C. Conversely, the number of H 2O ligands of Nd(H 2O) δ − n Cl n +3 − n complexes is uniformly reduced with temperature from 7.5 ± 0.8 to 3.7 ± 0.3 in the aqueous solution, in the same temperature range. These data show greater stability of neodymium(III) than gadolinium(III) and ytterbium(III) chloride complexes in low pH aqueous solutions at elevated temperatures. Our data suggest a greater stability of aqueous light REE than that of heavy REE chloride complexes in low pH fluids at elevated temperatures consistent with REE analysis of fluids from deep-sea hydrothermal vents.

Insights from soft X-rays: the chlorine and sulfur sub-structures of a CK2α/DRB complex

The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength of the primary X-ray beam is relatively close to the absorption edge of selected elements of the sample. The resulting effects are summarized as "anomalous dispersion" and can be always observed with "soft" X-rays (wavelength around 2 A) since they match the absorption edges of sulfur and chlorine. A particularly useful application of this phenomenon is the experimental detection of the sub-structures of the anomalous scatterers in protein crystals. We demonstrate this here with a crystal of a C-terminally truncated variant of human CK2alpha to which two molecules of the inhibitor 5,6-dichloro-1-beta-D-ribo-furanosyl-benzimidazole (DRB) are bound. The structure of this co-crystal has been solved recently. For this study we measured an additional diffraction data set at a wavelength of 2 A which showed strong anomalous dispersion effects. On the basis of these effects we detected all sulfur atoms of the protein, the two liganded DRB molecules and a total of 16 additional chloride ions some of them emerging at positions filled with water molecules in previous structure determinations. A number of chloride ions are bound to structural and functional important locations fitting to the constitutive activity and the acidophilic substrate specificity of the enzyme.

Interactions of the ethanolamino groups of nanofilms with Co(II), Ni(II), Cu(II), Zn(II), and Cr(III) ammoniates at the surface of PVC plates

Interactions of nanofilms containing ethanolamino groups with cobalt(II), nickel(II), copper(II), and zinc(II) ammoniates at the surface of polyvinylchloride plates and with chromium(III) ammoniate in a solution of ammonium chloride were studied. It was found that the groups of the film, together with chloride ions, displace all ammonia molecules from the inner coordination sphere of the metal. The average number of the ethanolamino N atoms of the film participating in formation of the metal ion coordination sphere is 3.35, 3.47, 3.67, 3.42, and 3.37 for Co2+, Ni2+, Cu2+, Zn2+, and Cr3+ complexes, respectively. The average number of chloride ions is 2 for Co2+, Ni2+, Cu2+, and Zn2+ and 3 for Cr3+. The coordination number of the central atoms is 6. The Cr3+ ion forms a coordination sphere composed of three N atoms and three chloride ions and a coordination sphere (charged 1+) made up of four N atoms and two chloride ions, with the third chloride ion being in the outer sphere. The Co2+, Ni2+, and Cu2+ ions form uncharged coordination spheres of two types: (1) with four N atoms and two chloride ions and (2) with three N atoms, two chloride ions, and the O atom of the ethanol hydroxyl group.

Occurrence of Soil Suppressiveness toFusariumWilt Disease of Broad Bean in Ismailia Governorate

AbstractFusarium oxysporumwilt of broad beati was studied in nonsuppressive and suppressive soil. One hundred and fifty soil samples were collected from 10 cultivated and reclaimed fields. The disease response of the 10 fields showed great variation. Percentages of diseased plants ranged from 19 to 85%. Soil samples collected from field Fm2 (soil No. 6, suppressive) showed the lowest percentage of diseased plant (19%), while all other soils showed not less than 40% of diseased plants. When the 10 field soil samples were inoculated withF. oxysporumthey exhibited a high receptivity value (over 50% diseased plants) while Fm2 soil showed almost the least value (less than 10% diseased plants). The fungal flora of the soil samples was studied where 64 spp. belonging to 37 genera were recovered. While the lowest number was recorded in soil Pk1 (soil No. 2, nonsuppressive) the highest total and species counts was found in Fm2 soil. Chemical analysis revealed that chloride and calcium ions were higher in Fm2 soil. The number of chloride ions was higher than calcium ions in all samples. Sugar cane bagasse, an organic supplement, and autoclaving enhanced the wilt disease development and retarded the suppressiveness of Fm2 soil.

Study of reactivity of Cl2 ?-toward aqua and chloro complexes of Co(II), Fe(II), and Mn(II) in aqueous solutions by pulse radiolysis method

1. The rate constants for the oxidation of the aqua and chloro complexes of Co(II), Fe(II), and Mn(II) by the Cl2−-ion-radical in aqueous solutions were measured by the pulse radiolysis method. 2. A substantial increase was observed in the oxidation rate with increase in the number of chloride ions in the inner coordination sphere of the complex was observed.

Raman Studies of Complex Ions in ThCl4–KCl Melt Using Raman Bands Shifts

Abstract Raman spectra of solid and molten ThCl4–KCl system were observed and the structure change of ThCl4 on melting from the octa-coordinate body-centered tetragonal type, D4h, to the tetra-coordinate tetrahedron type, Td, was studied. The decrease in frequency of the symmetric stretching vibration ν1 with decrasing ThCl4 concentration for molten ThCl4–KCl is interpreted as due to the presence of ThCl4, ThCl5−, and ThCl73− complexes in the molten ThCl4–KCl mixture. Such a compositional dependence for ν1 appears to support the idea that, for a decrease in the ThCl4 concentration in molten ThCl4–KCl mixtures, the bond strength between the thorium and chloride ions decreases and the number of chloride ions around the thorium ion increases from 4 to 7.

Thermal determination of the kinetics of the iron(III)–tin(II) redox reaction in chloride solution

From a temperature against time curve measured when a chemical reaction occurs in a batch reactor immersed in a constant temperature environment, it is possible to calculate both the rate constant and the enthalpy of a single reaction. This technique has been applied to the iron(III)–tin(II) redox reaction in chloride solution, studied over a twenty-fold variation in non-complexed chloride concentration and over a 50 K temperature range. Over this range of conditions the pseudo-second order rate constant for the reaction varied by a thousand-fold. Heats of reaction were also calculated.The experimental results obtained at 298 K agree with those of Duke and Pinkerton and support the finding that the rate-determining step involves chloro-complexes of the stannous and ferric ions. However, results at different temperatures indicate that rate-determining electron transfer occurs in precursor complexes of the tin(II), iron(III) and chloride ions rather than between iron(III) and tin(II) chloride complexes as suggested by Duke and Pinkerton. There is a common precursor complex for a given number of chloride ions. Furthermore, the enthalpies of activation of the electron transfer reaction in the precursor complexes are all the same and the different rate constants for electron transfer in each precursor complex is determined by the charge on the precursor complex.

Manganese(III) and its hydroxo- and chloro-complexes in aqueous perchloric acid: comparison with similar transition-metal(III) complexes

At 25°C the formation constant of MnCl2+ is found by spectrophotometry to be 13.2 ± 0.9 dm3 mol–1 at ionic strength 3.26 mol dm–3; for MnCl+2 the value is 1.1 ± 0.7 dm3 mol–1. Increase in the number of chloride ions in complexes results in longer wavelengths for the corresponding absorption maxima. In the absence of chloride the hydrolysis constant of MnIII at ionic strength 5.6 mol dm–3 is found from voltammetry and potentiometry to be 1.05± 0.26 mol dm–3. Aged managanese(III) is found to be 15–25% polymeric, from both kinetic and e.m.f. measurements. Comparison of formation constants for halogeno- and hydroxo-complexes of M3+(first transition series) shows that a combination of charge-transfer, ligand-field and coulomb interactions underlies the observed sequences; the dipole moment of OH– is also a factor.

Chloroaquo complexes of titanium(III). The 2T2g→2Eg absorption band

If the chloride ion content of aqueous titanium(III) solutions is gradually increased there is a continuous shifting of the 2T2g → 2Eg peak from c. 20100 cm-1 to c. 14500 cm-1. By applying the rule of average environment it is possible to draw a ?formation curve? for the number of chloride ions complexed to the central titanium(III) ion and hence to determine the equilibrium constants of the successive chloroaquo complexes as chloride ion replaces water in the octahedral environment. Of these, the first, K1 = {Ti(H2O)5Cl2+}aw/{Ti(H2O)3/6+}{Cl-}, was determined to be 0.07-0.2. The reflectance spectra of purple titanium trichloride hexahydrate (TiCl3,6H2O) and a 5% solution of a-titanium trichloride in KCl-LiCl eutectic mixture at 25� are shown to give ligand field bands in agreement with the above range of wave numbers.