Kinds Of Cations Research Articles

Structure and property of a Cu(II) compound bearing isopolyanion and flexible triol ligand

The investigations of the organic-inorganic hybrid materials attract widely attentions in recent years due to their applications in many fields, such as medicine, magnetism and catalysis. As one of the important types of inorganic components, polyoxometalates (POMs) bear the features of various compositions, rich structures and tunable charges, and play key roles in the construction of hybrid materials. Since the first [Mo7O24]6- polyanion was synthesized and its structure was confirmed by single-crystal X-ray analysis, many different kinds of cations, including inorganic and organic ions, were introduced to this system. While the studies of this type of polyanion with coordination compounds are still rarely, especially for transition metal ions and oxygenated ligands. As our ongoing study in the field of POM-containing compounds, we succeeded in obtaining an organic-inorganic hybrid based on [Mo7O24]6- polyanion in aqueous solution with CuSO4·5H2O, (NH4)6Mo7O24·4H2O and a triol ligand as staring materials. The formula of the obtained compound was determined as (NH4)2[CuL(H2O)]2MO7O24∙3H2O, L=(HOCH2)3CNH(CH2)3NHC(CH2OH)3 ( 1 ) through X-ray analysis, elemental analysis, IR spectrum and TG analysis. Single-crystal X-ray analysis reveals that compound 1 belongs to the monoclinic system with the space group of P 21. The unit cell parameters is a =10.778(2) A, b =21.391(3) A, c =11.596(3) A, α =90°, β =96.82(1)°, γ =90°, V =2654.4(9) A3, Z =2, and the final R 1 is 0.0155. In the crystal structure of compound 1 , Cu2+ cation is in a six-coordination environment and combines with ligand L in the unsymmetrical chelate coordination manner, where two triol groups provide one and two O atoms respectively and the other three positions are occupied by two N atoms and one O atom from water molecule. The [CuL(H2O)]2+ subunit connects with [Mo7O24]6- polyanion through the strong O−H∙∙∙O and N−H∙∙∙O hydrogen bonds to form a supramolecular two-dimensional network. TG curve shows that compound 1 has a good thermal stability until 160°C. The behavior of temperature dependence magnetic susceptibility of compound 1 in the range of 2−300 K expresses a strong antiferromagnetic property. In this work, the flexibility of the ligand plays a key role and provides the possibility for the formation of the unsymmetrical chelate coordination style of Cu2+. In addition, the high charge number of polyanion is an important factor for the construction of the two-dimensional network through providing more interactive sites.

Role of Additives on the Performance of CsPbI3 Solar Cells

The role of additives in the performance of CsPbI3 perovskite solar cells (PSCs) was investigated. Different kinds of cations and anions were used as additives in a N,N-dimethylformamide (DMF) solution containing CsI and PbI2 (1:1 molar ratio). These include HI, HBr, HCl, NH4I, NH4Br, and NH4Cl. Additive cations (H+ and NH4+) as well as halide ions (I–, Br–, and Cl–) are important for the properties of PSCs. Especially, the addition of iodine ion showed good characteristics compared to Br– and Cl–. Among the CsPbI3 layers prepared with different kinds of additives and annealed at different temperatures, the X-ray diffraction peaks of CsPbI3 were clearly found at 14° and 28° for the sample annealed at 150 °C with 50 μL of HI, suggesting the formation of a cubic structure at the low temperature of 150 °C. The field emission scanning electron microscopy images indicate that the surface of the perovskite layer with hydrogen halide additive (“H+”-based additive) is more uniform than that with ammonium additive. The roughness profiles determined by atomic force microscopy indicate that the CsPbI3 film with HI additive shows the least roughness among the samples with H+-based additives. Therefore, the best power conversion efficiency (PCE) of 4.72% is obtained for CsPbI3 PSCs annealed at 150 °C with HI (50 μL). The H+-based additives seem to react with PbI2 in DMF solution, increasing the solubility of PbI2 and thus lowering the processing temperature. Furthermore, the PCE of CH3NH3PbI3–xClx PSCs decreased from 7.45 to 0.23%, whereas that of CsPbI3 PSCs with 50 μL of HI only decreased from 3.55 to 2.78% after exposing the samples to air for 3 h. These results indicate that H+-based additives, especially HI, have more impact on the CsPbI3 PSCs in terms of lowering the processing temperature and improving the performance.

Ion-Responsive Drug Delivery Systems.

Some kinds of cations and anions are contained in body fluids such as blood, interstitial fluid, gastrointestinal juice, and tears at relatively high concentration. Ionresponsive drug delivery is available to design the unique dosage formulations which provide optimized drug therapy with effective, safe and convenient dosing of drugs. The objective of the present review was to collect, summarize, and categorize recent research findings on ion-responsive drug delivery systems. Ions in body fluid/formulations caused structural changes of polymers/molecules contained in the formulations, allow formulations exhibit functions. The polymers/molecules responding to ions were ion-exchange resins/fibers, anionic or cationic polymers, polymers exhibiting transition at lower critical solution temperature, self-assemble supramolecular systems, peptides, and metalorganic frameworks. The functions of ion-responsive drug delivery systems were categorized to controlled drug release, site-specific drug release, in situ gelation, prolonged retention at the target sites, and enhancement of drug permeation. Administration of the formulations via oral, ophthalmic, transdermal, and nasal routes has showed significant advantages in the recent literatures. Many kinds of drug delivery systems responding to ions have been reported recently for several administration routes. Improvement and advancement of these systems can maximize drugs potential and contribute to patients in the world.

Cations Diffusion in Nafion117 Membrane of Microbial fuel cells

The effects of five kinds of cations (Na+, K+, NH4+, Mg2+, Ca2+) in the anode phase on the diffusion of hydronium ions (H3O+) in the Nafion117 membrane and at the membrane/solution interface of a microbial fuel cell are investigated by means of molecular dynamics simulations and experiments. The cation diffusion laws are elucidated by the self-diffusion coefficients and the membrane conductivities. The results show that the presence of other cations in the membrane can lower the membrane conductivity and the intramembranous diffusion coefficient of H3O+, especially Ca2+. It is found that the NH4+ diffusion is susceptible to the membrane/solution interfacial structure and the presence of other cations in the membrane. The stable metal cations diffusion law (K+>Na+>Mg2+>Ca2+) is applicative to both intramembranous and interfacial structure, as well as the complex solution containing binary and multiple cations. The main factors affecting cations diffusion are hydrated radius, hydrated degree of cations, and the interaction between cations and sulfonic acid groups (-SO3H) of Nafion side chains. In addition, the formation of large size clusters or uniform distribution of cations in the membrane is conducive to their intramembranous diffusion and the connected region is conducive to the diffusion of cations through the membrane/solution interface.

Ionic Liquid Based Ultrasonic-Assisted Extraction of Oleanolic Acid from Grape Seeds

Ionic liquid based ultrasonic-assisted extraction (ILUAE) was successfully applied to extract Oleanolic acid (OA) from grape seeds. Different kinds of 1-alkyl-3-methylimidazolium ionic liquids with different kinds of cations and anions were studied and 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) solution was selected as extractants. The optimal conditions of ILUAE were determined by single factor experiments and Box-Behnken design as follows: [C4mim]Cl concentration of 0.7 mol/L, extraction time of 4 h, liquid-solid ratio of 15:1 mL/g, ultrasonic power of 195 W, the ultrasonication time of 13 min, and extraction temperature of 48℃·min. The extraction yield of OA was 13.4 mg/g, which is well in close agreement with the value predicted by the model. Compared with the regular ultrasonic-assisted extraction (UAE), the proposed approach exhibited 1.64 times higher efficiency, which indicated that ILUAE has a broad prospect for sample preparation of the bioactive compounds.

Ion chromatography with the indirect ultraviolet detection of alkali metal ions and ammonium using imidazolium ionic liquid as ultraviolet absorption reagent and eluent.

Indirect ultraviolet detection was conducted in ultraviolet-absorption-agent-added mobile phase to complete the detection of the absence of ultraviolet absorption functional group in analytes. Compared with precolumn derivatization or postcolumn derivatization, this method can be widely used, has the advantages of simple operation and good linear relationship. Chromatographic separation of Li(+) , Na(+) , K(+) , and NH4 (+) was performed on a carboxylic acid base cation exchange column using imidazolium ionic liquid/acid/organic solvent as the mobile phase, in which imidazolium ionic liquids acted as ultraviolet absorption reagent and eluting agent. The retention behaviors of four kinds of cations are discussed, and the mechanism of separation and detection are described. The main factors influencing the separation and detection were the background ultraviolet absorption reagent and the concentration of hydrogen ion in the ion chromatography-indirect ultraviolet detection. The successful separation and detection of Li(+) , Na(+) , K(+) , and NH4 (+) within 13 min was achieved using the selected chromatographic conditions, and the detection limits (S/N = 3) were 0.02, 0.11, 0.30, and 0.06 mg/L, respectively. A new separation and analysis method of alkali metal ions and ammonium by ion chromatography with indirect ultraviolet detection method was developed, and the application range of ionic liquid was expanded.

A sandwich-type POM containing mixed cations: synthesis, thermal performance and proton-conducting properties

A new sandwich-type polyoxometalate, Na5H[N(CH3)4]2[Co(C3N2H4)2(H2O)4][Co4(H2O)2(PW9O34)2]·21H2O (1), has been synthesized. 1 is composed of a Weakley-type polyanion, [Co4(H2O)2(PW9O34)2]10−, four kinds of cations (five Na+, two [N(CH3)4]+, one [Co(C3N2H4)2(H2O)4]2+, and one H+), and 21 crystalline H2O molecules. The surface oxygen of the polyanion in 1, the crystalline water, and coordinated water molecules make an extended 3-D hydrogen-bonding network. Alternating current (AC) impedance experiments of 1 reveal good proton conductivity for 1 of 5.03 × 10− 4 S cm−1 at 25 °C under 98% relative humidity (RH). Activation energy of 1 calculated from Arrhenius plots is 0.358 eV, indicating Grotthuss mechanism is dominant in the proton transfer. Thermal decomposition behavior of 1 was examined by thermogravimetry/mass spectrometry (TG/MS) measurements.

Halocadmium Clusters with Different Linkage Modes Templated by Methyl Viologen: Structure, Photoluminescence, and Thermochromism

A new halocadmium/methyl viologen hybrid (MV)4(Cd2I6)(Cd2I7)2 (1) (MV2+ = methyl viologen) has been structurally determined. In 1, two kinds of dimeric halocadmium clusters constructed from edge/vertex-sharing CdI4 tetrahedra respectively, i.e., Cd2I6 2− and Cd2I7 − dimmers were observed, which were templated by methyl viologen cation (MV2+). A highly interesting feature of 1 is the presence of mixed type dimeric halocadmium clusters in one crystal lattice templated by one kind of cation. 1 displays photoluminescences, and its thermochromism behavior is observed, whose mechanism was verified by theoretical calculations.

Effect of cation substitution on the magnetic and magnetotransport properties of epitaxial Fe3−xVxO4 films

The effect of cation on the structure, magnetic and magnetotransport properties of epitaxial Fe3−xVxO4 (0≤x≤0.6) films fabricated by reactive cosputtering was investigated systematically. Four kinds of cations (Fe2+, Fe3+, V2+ and V3+) exist in the Fe3−xVxO4 films. The Fe3−xVxO4 films reveal semiconducting property and increased resistivity with increasing V content. The systematic change of the decreased saturation magnetization and enhanced exchange bias is closely related to the spin canting and antiferromagnetic coupling, which is caused by the V substitution on B sites. The presents of V2+ (3d3) enlarge the anisotropy, and further increase the coercivity. With the combined effects of the larger anisotropy, spin canting and enhanced antiferromagnetic coupling caused by V substitution, the Fe3−xVxO4 films exhibit enhanced four-fold symmetric anisotropic magnetoresistance.

Development of an ionic liquid-based microwave-assisted method for the extraction and determination of taxifolin in different parts of Larix gmelinii.

An ionic liquid-based microwave-assisted extraction method (ILMAE) was successfully applied for the extraction of taxifolin from Larix gmelinii. Different kinds of 1-alkyl-3-methylimidazolium ionic liquids with different kinds of cations and anions were studied and 1-butyl-3-methylimidazolium bromide was chosen as the optimal solvent for taxifolin extraction. The optimal conditions of ILMAE were determined by single factor experiments and Box-Behnken design as follows: [C4mim]Br concentration of 1.00 M, soaking time of 2 h, liquid-solid ratio of 15:1 mL/g, microwave irradiation power of 406 W, microwave irradiation time of 14 min. No degradation of taxifolin had been observed under the optimum conditions as evidenced from the stability studies performed with standard taxifolin. Compared with traditional solvent and methods, ILMAE provided higher extraction yield, lower energy and time consumption. The distribution of taxifolin in different parts of larch and the influences of age, orientation, and season on the accumulation of taxifolin were analyzed for the sufficient utilization of L. gmelinii.

The High Temperature Operation of Lithium Secondary Batteries with Using Ionic Liquids

Ionic liquids (ILs) composed of perfluoroanion such as BF4 − and bis(trifluoromethylsulfonyl)amide (([(CF3SO2)2N]−, Tf2N−) have attracted attention as less flammable and less volatile electrolyte for a lithium secondary battery for past decade. Especially, Tf2N- forms ILs not only 1-ethyl-3-methylimidazolium (C2mim+), but also various aliphatic quaternary ammonium (AQA+). The AQA-Tf2N exhibited large apparent electrochemical windows enough wide to use a solvent free electrolyte for a 4 V-class battery such as a LiCoO2 half-cell. Though the rate properties of the cell at room temperature were much lower than that for a conventional organic solvents, another promising ILs composed of bis(fluoromethylsulfonyl)amide (f2N−) are dramatically improved the rate property of the cells using ILs. However, it should be focused on not only the rate performance but also the actual thermal stability of the cells using ILs, which might not depend on only the thermal stability of ILs.[1] In this presentation, we would like to show the effect of cationic species of Tf2N--ILs on the cycle stability of a cathode half-cell at high temperature over 100 °C. For this purpose, a conventional LiFePO4 cathode composed of polyvinylidene fluoride (PVDF) (KUREHA, #1120) as binder and acetylene black (AB) as the conductive additive. We found that the rate property of the LiFePO4half-cells were much improved over 85 °C and also the cycle performance of the cells over 100 °C were much depend on the kind of cation in ILs. Acknowledgements A part of this work was supported by the R&D project for Li batteries by NEDO of Japan (Li-EAD) and Advanced Low Carbon Technology Research and Development Program (ALCA) of Japan Science and Technology Agency (JST). Reference [1] H. Matsumoto, in Electrolytes for Lithium-ion Batteries, eds. T. R. Jow, K. Xu, O. Borodin and M. Ue, Springer, 2014, ch.4 and references therein.

Synthesis, structure and green luminescence evolution of apatite-type Sr3.5Y6.5O2(PO4)1.5(SiO4)4.5:Eu2+,Tb3+ phosphors

Eu2+–Tb3+ co-doped Sr3.5Y6.5O2(PO4)1.5(SiO4)4.5 (SYPSO) phosphors with apatite structure have been synthesized via a high temperature solid-state reaction and their luminescence properties have been investigated in detail. The two kinds of cations׳ sites and complex phosphate-silicate anions׳ structural character of SYPSO host have been studied. The SYPSO:Eu2+,Tb3+ phosphors show a broad absorption band ranging from 250 to 420nm, which is well matched with the emission of near ultraviolet (UV) chips, and it exhibited two dominating bands peaked at 502 and 543nm upon 365nm excitation. The emission color of SYPSO:0.05Eu2+,yTb3+ shows a controlled luminescence evolution of the color hue in the green area owing to the Eu2+–Tb3+ energy transfer (ET) process, and their chromaticity coordinates (x, y) can be varied from (0.2723, 0.3766) to (0.2812, 0.4537). The ET efficiency as well as the critical distance is also estimated. The quantum efficiency and thermal quenching properties have also been studied in this paper in order to demonstrate its potential application for white light-emitting diodes (w-LEDs) phosphors.

Cation···π interactions: QTAIM and NBO studies on the interaction of alkali metal cations with heteroaromatic rings

The cation···π interactions of alkali metal cations (Li+, Na+, and K+) with five-membered heteroaromatic rings [furan(C4H4O), thiophene(C4H4S), pyrrole(C4H5N)] were examined by high level ab initio calculations, to investigate the different roles of C4H4O, C4H4S, and C4H5N as the electron donor, the influential factors that affect these interactions, the nature of this kind of cation···π interaction, and to determine topological and energetical properties to characterize these interactions. The sulfur atom in C4H4S plays a certain role in the cation···π interactions except the C–C π bond, which is different from C4H4O and C4H5N. The size of cation and the character of heteroaromatic ring are two influential factors that affect the cation···π interactions. The studied cation···π interactions can be classified as “closed-shell” and noncovalent interactions. The electron density and its Laplacian at the bond critical points and ring critical points generated upon complexation are useful measurements for the strength of cation···π interactions.

Synthesis and thermophysical properties of imidazolate-based ionic liquids: Influences of different cations and anions

Six novel imidazolate-based room-temperature ionic liquids (ILs), 1-butyl-3-methylimidazolium imidazolate ([Bmim][Im]), 1-ethyl-3-methylimidazolium imidazolate ([Emim][Im]), 1-hydroxylethyl-3-methylimidazolium imidazolate ([HO-emim][Im]), 1-aminopropyl-3-methylimidazolium imidazolate ([NH2-pmim][Im]), 1,4-Bis(3-methylimidazolium-1-yl)butane imidazolate ([Bis(mim)C4][Im]2) and 1,2-Bis(3-methylimidazolium-1-yl)ethane imidazolate ([Bis(mim)C2][Im]2), were prepared with different kinds of cations, including conventional monocation, functionalized cation and dication. Their main physicochemical properties were measured, consisting of glass transition temperature, density, conductivity and viscosity. The influences of the cationic structure on each property were highly discussed. The results showed that the glass transition temperature increased with the decreasing alkyl chains length of cation and dication, whereas the density exhibited an opposite behavior. The viscosity of dicationic and functionalized ILs increased compared to conventional monocationic ILs. However, the conductivity was found to decrease after using dication and functionalized cation. In addition, the density and conductivity of imidazolate ILs were determined as the functions of temperature from T=(293.15 to 343.15)K. Vogel–Tammann–Fulcher and Arrhenius equations were utilized to study the temperature-dependence of conductivity. Moreover, the thermal expansion coefficients were calculated from the (density+temperature) dependence, the relationship between viscosity and conductivity was discussed using Walden plots.

Amorphous silicon nitride thin films implanted with cerium ions for cathodoluminescent light source

Cerium ions were implanted into amorphous silicon nitride thin films, and the cathodoluminescence (CL) of the thin films was investigated. The Ce ions were distributed within a depth of around 20nm from the surface of the amorphous silicon nitride, and they formed three kinds of cations in the thin films. By implanting the Ce ions, the CL of the films was distributed around a wavelength of 405nm. The CL increase of more than 2.2 times compared to silicon nitride thin films was observed at 25-kV electron beam excitation. This increase was significantly enhanced by adopting a high-temperature annealing process after the cerium-ion implantation.

Selective adsorption of ions in charged slit-systems

We study the selective adsorption of various cations into a layered slit system using grand canonical Monte Carlo simulations. The slit system is formed by a series of negatively charged membranes. The electrolyte contains two kinds of cations with different sizes and valences modelled by charged hard spheres immersed in a continuum dielectric solvent. We present the results for various cases depending on the combinations of the properties of the competing cations. We concentrate on the case when the divalent cations are larger than the monovalent cations. In this case, size and charge have counterbalancing effects, which results in interesting selectivity phenomena.

Effects of cation composition in the electrolyte on the efficiency improvement of black dye-based dye-sensitized solar cells

The effects of the addition of the tetrabutylammonium cation in the electrolyte on the performance of a black dye-based dye-sensitized solar cell (DSC) have been investigated. The conversion efficiency of the cosensitized DSC with black dye and D131 was improved to 11.8% by using an electrolyte containing three kinds of cations.

Self-Limited to Parabolic Grain Growth Kinetics in Metal Oxide Thin Films

Distinctive microstructure engineering of amorphous to nanocrystalline electroceramic thin films is of high relevance for integration in low to high temperature operating MEMS-devices. Up to now, kinetic rules of nucleation, crystallization and grain growth of precipitation-based ceramic thin films are unknown. In this study, general rules for the crystallization and grain growth kinetics of a pure single-phase metal oxide thin film with only one kind of cation, i.e. ceria, made by spray pyrolysis from a precursor with one single organic solvent is discussed [1,. The near-and long range disorder is studied via Raman, DSC investigation of crystallization enthalpy, XRD, SEM and TEM for amorphous to fully crystalline state. These 400 nm thick-thin films were dense, crack-free and amorphous directly after deposition on a sapphire substrate. Briefly, above deposition temperature crystallization sets in with respect to temperature and persists over a broad temperature range from 400 to 950°C. In this regime, biphasic amorphous-crystallien films exist and grain growth proceeds simultaneously to crystallization. Isothermal grain growth studies showed that after short dwell times of 10-20h stable microstructures established following self-limited grain growth law [. In this state, driving force for the crystallization is the reduction of free enthalpy for phase transformation and interface diffusion prevails. A transition to classical grain curvature-driven parabolic grain growth kinetics appeared once the material reached the fully crystalline state for average grain sizes larger than 140 nm and higher annealing temperatures. Volume diffusion was then activated in addition to the interface diffusion. It was found that once crystallized the material shows independent on processing route equal XRD density and microstrain, as well as Raman characteristics. However, dependent on processing conditions i.e. choice of organic and, according, deposition temperature of the film amorphous states vary and affect strongly crystallization and grain growth history for the biphasic films.

Dynamical and thermodynamic properties of Ag+ and Cu+ halide mixtures

Molecular dynamics simulation has been performed to investigate the dynamical and thermodynamic properties of the superionic and molten phases for (Ag x Cu1 − x )Br of x < 0.5, which contains two kinds of cations, Ag+ and Cu+. Ag+ and Cu+ ions show different transport and dynamical properties in superionic phase. Their frequency distributions are found in the infrared region. The concentration–concentration structure factor, Sc i c j (q), has also been evaluated.

Spontaneous periodic pulsation of contact line in oil/water system – Frequency control with divalent cations and applied voltage

Periodic oscillatory change of hydrophilicity (or hydrophobicity) of a glass surface was studied. A glass capillary was immersed normally at an oil/water interface. The water phase contained the cationic surfactant trimethyloctadecylammoniumchloride, and the oil phase contained bis(2ethylhexyl) phosphate. Adsorption of the surfactant molecules and their desorption via anionic chemicals dissolved in the oil generated a gradual wetting by the water, followed by a rapid wetting by oil. The three phase contact line exhibited a pulse-like motion that continued, at least for a few minutes. The frequency depended on the cation species dissolved in water and the applied voltage across the oil/water interface. Four kinds of cations, Mg2+, Ca2+, Sr2+ and Ba2+ were used. While the frequency order was Ba2+>Sr2+>Mg2+, the Ca2+-containing interface did not show any motion irrespective of the applied voltage. There was a threshold voltage and concentration of anionic chemical that was necessary for the onset of this motion. The pulsation mechanism and its ion selectivity are also discussed. This interfacial motion was a typical nonlinear oscillation with an ion-selective nature. In this regard, this interfacial motion had biomimetic characteristics.