Thionyl Chloride Solutions Research Articles

Two D-π-A Schiff-Base-Functionalized Silica Gel Adsorbents for Preconcentration of Copper Ions in Foods and Water for Detection.

Copper is an essential element in many biological processes and plays an important role in carbohydrate and lipid metabolism. Excess or deficiency of Cu ions can cause disturbances in cellular homeostasis and damage the central nervous system. Here, for the first time, two functionalized silica gel (SG-A and SG-B) adsorbents were prepared and tested for copper detection via the reactions of chlorinated silica gel with two novel D-π-A Schiff base compounds: 2-amino-3-(quinolin-2-ylmethyleneamino)maleonitrile (A) and 2-(4-(diethylamino)-2-hydroxybenzylideneamino)-3-aminomaleonitrile (B) in the thionyl chloride solution, respectively. SG-A and SG-B as adsorbents filled in a microcolumn were used to enrich trace Cu ions in foods and water with the detection of flame atomic absorption spectrometry. Because of the strong coordination between two D-π-A Schiff base compounds and Cu2+ ions, the stable heterocyclic Cu2+-SG-A/B complex is formed. For a sample volume of 30 mL, detection limits of 0.09 μg L-1 and 0.15 μg L-1 have been achieved. The results of selectivity study show that the two adsorbents can selectively extract Cu2+ in complex matrixes with other metal cations. The methods have been successfully applied to the determination of Cu2+ content in various real samples, and the detection sensitivity that we report here is better than most results reported using modified silica gels.

Wormlike Micelle Assisted Rod Coating: A General Method for Facile Fabrication of Large-Area Conductive Nanomaterial Thin Layer onto Flexible Plastics

Through combined application of wormlike-micelle and rod-coating technique, a general method was demonstrated for the facile reparation of thin transparent conductive films (TCF) of various nanomaterials and their hybrids on flexible plastics. The cetyltrimethylammonium hydroxide (CTAOH)/p-toluenesulfonic acid (CTAT) wormlike micelle system was selected for both the dispersion of different nanomaterials and the enhancement of viscosities of the coating fluids. With the single-walled carbon nanotubes (SWNTs)/wormlike micelle aqueous dispersions as coating fluid, TCFs of SWNTs on flexible poly(ethylene terephthalate) (PET) substrates made by rod-coating method were demonstrated. After doping by immersion into thionyl chloride solution, the sheet resistance of SWNTs thin films, which had a transmittance of about 78%, was as low as 480Ω/sq. This coating method was extended to the preparation of thin films or networks of other materials such as reduced graphene oxide and Ag nanowires. The obtained TCF from Ag nanowire networks has a low sheet resistance of 17Ω/sq, which is comparable to the value of best indium tin oxide (ITO) coating on plastic substrates. Finally, hybrid thin films of different nanomaterials were demonstrated by this method.

Microelectrode studies of reversible Mg deposition in THF solutions containing complexes of alkylaluminum chlorides and dialkylmagnesium

A kinetic study of Mg deposition on Pt surfaces has been performed using Pt microelectrodes. The solutions chosen included tetrahydrofuran (THF) and several types of Mg–Al–R–Cl complex electrolytes from which magnesium can be deposited reversibly. The complexes included an all-inorganic, Cl-containing MgCl 2:AlCl 3 (1:1) complex compound, all-organic Bu 2Mg with different ratios of Bu 2Mg, and various combinations of AlEtCl 2 and AlEt 3. Tafel slopes of the resulting polarization curves obtained both by CV and potential step techniques were carefully analyzed within the framework of a complicated, three-stage electrocrystallization mechanism related to four consecutive and two parallel steps in the first stage (ad-atom formation on the metallic interface) followed by surface diffusion and embedding of Mg-ad-atoms in the growth kink sites. This mechanism not only explains the peculiar kinetic data on Mg deposition from these complex solutions, but also provides a natural route for the comparison of a Mg deposition mechanism with that of gold and Ni depositions from cyanide and AlCl 3–BPC–NiCl 2 room temperature molten salts, respectively. We also discuss the uniqueness of these THF-based complex solutions for metallic Mg deposition, and compare the electrodeposition mechanism in this electrolyte with the electrochemistry of Mg in thionyl chloride solutions.

Electrocatalytic effects of thionyl chloride reduction by polymeric Schiff base transition metal(II) complexes

Electrocatalytic effects for the reduction of thionyl chloride in LiAlCl 4/SOCl 2 electrolyte solution containing polymeric Schiff base M(II) (M: Ni and Cu) complexes were evaluated by determining kinetic parameters with cyclic voltammetry at a glassy carbon electrode. The charge transfer process during the reduction of thionyl chloride was affected by the concentration of the catalyst. The catalytic effects were demonstrated from both a shift of the reduction potential for the thionyl chloride in a more positive direction and an increase in peak currents. The reduction of thionyl chloride was found to be diffusion-controlled. Catalytic effects are larger in thionyl chloride solutions containing (PVPS)M(II)(SALPR) rather than in those containing (PVPS)M(II)(SALPE). Such results are opposite to those for monomeric Schiff base complexes. Significant improvements in the cell performance were found in terms of both thermodynamics and kinetic parameters for the thionyl chloride reduction. An exchange rate constant, k o, of 1.62×10 −8 cm/s was found at a bare electrode, while larger values of (4.69–8.18)×10 −8 cm/s were observed at the catalyst-supported glassy carbon electrode.

Studies on electrochemical properties of thionyl chloride reduction by Schiff base metal(II) complexes

Electrocatalytic effects associated with the reduction of thionyl chloride in a LiAlCl 4–SOCl 2 electrolyte solution containing Schiff base metal(II) (metal (M): Co, Ni, Cu and Mn) complexes are evaluated by determining the kinetic parameters for the reactions using cyclic voltammetry at a glassy carbon electrode. The charge-transfer process during the reduction of thionyl chloride is affected by the concentration of the catalyst. Catalytic effects are demonstrated from both a shift in the reduction potential for the thionyl chloride in a more positive direction and an increase in peak currents. The reduction of thionyl chloride is diffusion controlled. Catalytic effects are larger for thionyl chloride solutions containing M(II)(1,5-bis(salicylidene imino) pentane) (M(II)(SALPE)) rather than M(II)(1,3-bis(salicylidene imino) propane) (M(II)(SALPR)). Significant improvements in cell performance are found in terms of the both thermodynamics and kinetic parameters for the thionyl chloride reduction. An exchange rate constant, k 0, of 1.89×10 −8 cm s −1 is found at the bare electrode, while larger values of 2.79×10 −8 to 2.09×10 −6 cm s −1 are observed in the case of the catalyst-supported glassy carbon electrode.

Wall coating for DNA sequencing and fragment analysis by capillary electrophoresis

In capillary electrophoresis, covering the inner capillary surface with a coating is an efficient way to minimize both the electroosmotic flow and sorption of w analytes on the capillary wall. We modified the procedure by Cobb et al. Anal. . x Chem. 62, 2478 1990 for preparing wall coating to permit large-scale production. Specifically, we use a positive pressure to fill the capillary with both thionyl chloride and later vinylmagnesium bromide solution. This enables large-scale production of the coating by treating 100 m capillary pieces at a time. We found that no extensive flushing with either organic solvents or sodium hydroxide is needed before the reactions are performed. Application of liquid thionyl chloride with positive pressure scavenges residual humidity on the capillary surface and eliminates a need for extensive drying of the capillary. In the polymerization step, elimination of TEMED from the polymerization mixture and incubation at 708C enables a homogeneous coating to be prepared in capillaries as long as 100 m. The prepared wall coating is stable for approximately 110 runs of DNA sequencing in a denaturing matrix and over 300 runs of DNA fragment analysis under nondenatur- ing conditions. Q 1998 John Wiley & Sons, Inc. J Micro Sep 10: 175)184, 1998

Coordination in thionyl chloride solutions of alkali metal salts

The solution structure of alkali metal tetrachloroaluminates dissolved in thionyl chloride has been investigated using far infrared and Raman spectroscopy with measurements of depolarization ratios. The solvent is strongly coordinated to the alkali metal cation with a consequent shift of electron density away from the sulfur-chlorine bonds.

Electron spin resonance studies of the oxidation of [Tc V NCl2(EPh3)2](E = P or As) to [Tc VI NCl4]? by thionyl chloride: structure of dichloronitridobis(triphenylarsine)-technetium(V)

The complexes [TcVNCl2(EPh3)2](E = P or As) are oxidized to [TcVINCl4]– in thionyl chloride solution at room temperature. ESR spectroscopy has established the presence of technetium(VI) intermediates, [TcNCl3(EPh3)]: E = P, g∥= 2.0316, g⊥= 2.0026, A∥= 0.0267 cm–1, A⊥= 0.0119 cm–1, Q= 0.000 35 cm–1, ax=ay= 0.0017 cm–1, ax= 0.00185 cm–1; E = As, g∥= 2.0246, g⊥= 1.9986, A∥= 0.0271 cm–1, A⊥= 0.0125 cm–1, Q= 0.0003 cm–1, ax=ay= 0.00195 cm–1 and az= 0.0021 cm–1. The crystal structure of [TcNCl2(AsPh3)2]1 has been determined and is compared with those of ReVN and TcVN phosphine complexes. Crystals of 1 are monoclinic, space group I2/a with a= 15.823(4), b= 9.638(2), c= 22.490(7)Å, β= 101.91 (2)° and Z= 4. Molecules of 1 possess C2 symmetry with NTc–Cl and NTc–As angles of 110.51 (3) and 99.22(1)°, respectively. The TcN bond length is 1.601(5)Å.

Properties of thionyl chloride solutions (extended abstract)

Properties of thionyl chloride solutions (extended abstract)

Solid electrolyte interphase (SEI) electrode—V. the formation and properties of the solid electrolyte interphase on calcium in thionyl chloride solutions

The electrochemical behaviour of calcium in neutral thionyl chloride solutions containing FeCl 3, AlCl 3, CaCl 2 and CaO was investigated using pulse galvanostatic and ac techniques. In all systems the calcium electrode is completely covered by a passivating layer consisting of CaCl 2 which serves as a SEI. The SEI is probably an anionic conductor. The ionic transport number ( t i) of the SEI under OCV conditions was calculated from the ratio: OCV/thermodynamic EMF. It is about 0.9 for AlCl 3-based electrolytes and about 0.8 for FeCl 3-based electrolytes. Immediately after laoding the cell at about 10mA cm t–2 its OCV reaches 3.7 V indicating that t i reaches unity and the OCV of the cell equals the thermodynamic value. The electrode reaction resistance and the apparent thickness of the SEI varies with type and concentration of the electrolyte and with storage time. When an aged electrode is anodically dissolved, the reaction resistance drops by three orders of magnitude, and the SEI-resistivity drops by two orders of magnitude. The mechanism responsible for the ”diode” behaviour of the calcium-SEI electrode in thionyl chloride is discussed.

ChemInform Abstract: The Chemistry of Polyhalozirconates. Part 1. Zirconium Oxide Chloride, a Source of the Anions ZrCl‐ 5 and ZrCl2‐ 6.

AbstractConductimetric studies of thionyl chloride solutions of ZrCl4 and ZrOCl2·8 H2O indicate that the solvated species in the two solutions are different.

The chemistry of polyhalozirconates. Part 1. Zirconium oxide chloride, a source of the anions ZrCl 5− and ZrCl 62−

Conductimetric studies of thionyl chloride solutions of ZrCl 4 and ZrOCl 2·8H 2O indicate that the solvated species in the two solutions are different. From such solutions the synthesis of two types of pentachlorozirconates are reported. The synthesis of hexachlorozirconates from each solution is also reported.

Metal‐Solvent Interactions of Iron and Naphthalocyanines With Thionyl Chloride: An Xps Approach

AbstractX‐ray photoelectron spectroscopic investigations have been performed on phthalocyanine and naphthalocyanine samples previously exposed to thionyl chloride or dissolved into thionyl chloride solutions. With Fe and Mo compounds, fast oxidation of the central metal has been observed, and the data illustrate the dissociative character of the SOCl2 chemisorption.

The a.c. response of lithium, stainless steel, and porous carbon electrodes in thionyl chloride solutions

Impedance measurements on Li electrodes in SOCl 2 electrolytes indicate that the structure of the passivating surface layer formed in 1.8M LiAlCl 4 differs from that formed in 1.8M AlCl 3, 1.2M LiCl, 0.6M SO 2. Also, porous carbon electrodes are found to behave differently in these two electrolytes. Unpolarised stainless steel electrodes show a 67° constant phase angle impedance over a wide frequency range whereas polarised to O mV vs. Li the impedance diagram is very similar to that of Li. Finally, it is found that passivation may develop differently for Li pressed onto stainless steel from that of Li pressed onto glass.

ChemInform Abstract: SOLID ELECTROLYTE INTERPHASE (SEI) ELECTRODE. PART III. DEPOSITION‐DISSOLUTION PROCESS OF LITHIUM IN THIONYL CHLORIDE SOLUTION

AbstractDer Abscheidungs‐Au?Ösungs‐Mechanismus von Li an Edelstahl‐ und Ca‐Elektroden in 1 M LiAlCl4‐SOC12‐Lösung wird mit Hilfe galvanostatischer Impuls‐ und Wechselstrommethoden ebenso wie Bildung und Eigenschaften einer Festelektrolytgrenzphase untersucht.

Solid electrolyte interphase (SEI) electrode: Part III. Deposition-dissolution process of lithium in thionyl-chloride solution

The deposition-dissolution mechanism of lithium on stainless steel and calcium electrodes in 1 M LiAlCl 4 -thionyl-chloride solution is studied by pulse galvanostatic and ac techniques. The metal -solution interfacial capacitance of the stainless steel electrode is about 30 μF cm −2 which is higher by an order of magnitude than the capacitance of lithium-coated stainless steel and either pure or lithium-coated calcium. The lower capacitance is attributed to the existence of a solid electrolyte interphase (SEI) on the coated stainless steel or the calcium electrode. Significantly different is observed upon deposition of lithium on stainless steel or calcium. Deposition on stainless steel takes place only after prior formation of a SEI on the electrode (by passage of about 20 mC cm −2), while deposition on calcium starts immediately after the electrode capacitance has been charged (by about 5 μC cm −2). Furthermore, deposition of about 3% of a monolayer of lithium on calcium is enough to stabilize its potential at 0.0 V vs. LiRE. On the lithium-coated stainless steel electrode, a linear relationship between the current and over-potential is observed for up to 700 mV. This indicates a Tafel slope > V. During lithium deposition on stainless steel, the SEI resistivity is about 1.5 × 10 7 Ω-cm and its thickness is about 10 nm. Under open circuit potential, the deposited lithium corrodes at an apparent rate of 100 μA cm −2. Rapid fluctuations of the electrode potential during the corrosion or dissolution process are accounted for by a break and repair mechanism of metallic contact between lithium deposited within the SEI and the current collector.

Electrochemical Behavior of Copper in Thionyl Chloride Solutions

The electrochemical and chemical behavior of copper and copper chlorides was studied in solutions using cyclic voltammetric, controlled potential electrolysis, and x‐ray techniques. It was shown that copper metal reacts with thionyl chloride even at ambient temperatures resulting in the formation of cuprous chloride and cupric sulfide. In solutions, cuprous chloride is further oxidized, chemically as well as electrochemically, to cupric chloride. Cupric chloride was found to be electroactive in these solutions and undergoes reduction in the solid state to cuprous chloride and copper, respectively. It was also found that due to the presence of copper chloride films at the copper metal electrode in these solutions, the electrochemical reduction of thionyl chloride at copper electrodes occurs at more negative potentials than observed at carbon electrodes.

Solid Electrolyte Interphase (SEI) Electrode: II . The Formation and Properties of the SEI on Magnesium in Solutions

Magnesium metal immersed in thionyl chloride solutions becomes covered by a passivating layer which has properties of solid electrolyte. The buildup and the electrochemical properties of this layer were studied. Tafel slopes measured on freshly immersed Mg electrodes depend linearly on the apparent thickness of the SEI. The reaction resistance and the differential capacitance, on Mg and W electrodes, were measured by several methods. Values of the electrochemical parameters depend on the bias potential. The metal/solution interfacial capacitance of W electrode is higher by an order of magnitude than that of Mg electrode. This higher capacitance decreases markedly, under cathodic polarization.

The Kinetics of the Magnesium Electrode in Thionyl Chloride Solutions

The electrochemical behavior of the magnesium electrode in thionyl chloride (TC) solutions was studied. It was found that this electrode is covered by a passivating layer which consists of some insoluble magnesium salt, probably. The properties of this layer determine the chemical and electrochemical behavior of the electrode in TC solutions. Magnesium was deposited on a nickel cathode from TC solutions containing . Magnesium deposition begins after the nickel cathode is covered by a passivating layer (consisting of reduction products of TC) in which . It was concluded that the rds for the deposition‐dissolution process of the magnesium electrode in TC solutions is not the electron‐transfer reaction, but is instead the migration of the ions through a passivating layer which covers the electrode.

Reactions of tetrasulphur tetranitride with halides. Part II. Some metal halides in thionyl chloride

The reactions between tetrasulphur tetranitride and chlorides of (a) manganese(II) and cobalt(II); (b) zinc, chromium(III), iron(III), and zirconium(IV); (c) antimony(v); and (d) beryllium in thionyl chloride solution or suspension have been found to give products of the types (a) SNMCl2, (b) S2N2MCln, (c) S3N3SbCl6, and (d) S2N2OBeCl2(M = metal). I.r. spectra are reported. The possibility that some of these compounds contain new ring-systems is discussed.