Sodium Halides Research Articles

Cavity-modulated ionization potentials and electron affinities from quantum electrodynamics coupled-cluster theory

Quantum electrodynamics coupled-cluster (QED-CC) theory is used to model vacuum-field-induced changes to ground-state properties of a series of sodium halide compounds (NaX, X = F, Cl, Br, and I) strongly coupled to an optical cavity. Ionization potentials (IPs) and electron affinities (EAs) are presented, and it is demonstrated that EAs are easily modulated by cavity interactions, while IPs for these compounds are far less sensitive to the presence of the cavity. EAs predicted by QED-CC can be reduced by as much as 0.22 eV (or ≈50%) when considering experimentally accessible coupling parameters.

Electrocatalytic tandem assembly of aldehydes with 2-thiobarbituric acid into 5,5'-(arylmethylene)bis(1,3-diethyl-2-thiobarbituric acids) and evaluation of their interaction with catalases

Electrocatalytic transformation of aldehydes with two equivalents of 1,3-diethyl-2-thiobarbituric acid has been carried out in alcohols in an undivided cell in the presence of sodium halides with the selective formation of the substituted 5,5'-(arylmethylene)bis(1,3-diethyl-2-thiobarbituric acids) in 87–98% yields and with 870–980% current efficiency. This new one-pot electrochemically induced tandem Knoevenagel–Michael process is a simple and efficient approach to substituted 5,5'-(arylmethylene)bis(1,3-diethyl-2-thiobarbituric acids) containing two 1,3-diethyl-2-thiobarbituric acid fragments separated by C-aryl-substituted spacer, which are promising compounds for different biomedical applications, including anticonvulsant, antiAIDS agents and anti-inflammatory remedies. Theoretical studies were carried out to investigate the interaction of the synthesized compounds with beef and human catalases.

Ceftriaxone Degradation in the Presence of Sodium Halides Investigated by Electrochemical Methods Assisted by UV-Vis Spectrophotometry

The electrochemical stability of ceftriaxone (CFTX), belonging to the third generation of cephalosporin antibiotics, was studied by electrochemical measurements recorded on a platinum electrode (Pt) in aqueous solutions containing sodium halides. The electrochemical behavior of ceftriaxone was investigated by cyclic voltammetry (CV) and constant current density electrolysis assisted by UV-Vis spectrophotometry. Cyclic voltammetry highlighted that the addition of CFTX in sodium halide solutions leads to significant changes in the hysteresis characteristics due to specific interactions with active species from electrolytes, as well as with the platinum electrode surface. After CV, when an exterior electric stimulus in short time (40 s) was applied, the UV-Vis spectra illustrated that CFTX is stable in the presence of F− ions, it is electro(degraded/transformed) in the presence of Cl− and Br− ions and interacts instantly with I− species. Electrolysis at constant current density confirms the results obtained from cyclic voltammetry, showing that (i) in the presence of fluoride ions CFTX gradually decomposes, but not completely, in about 60 min, without identifying a reaction product; (ii) chloride and bromide ions determine the almost complete CFTX electro(degradation/transformation) in 10 and 5 min, respectively, with completion of the electro-transformation reaction after 60 and 30 min, respectively; (iii) instantaneous interactions between CFTX and the iodide ions occurred.

Experimental and theoretical study of the effect of typical halides on thermal decomposition products and energy release of ammonium nitrate based on microcalorimetry and FTIR

Ammonium nitrate (AN) is widely used as a raw material in industry and agriculture. However, the Beirut explosion in Lebanon once again shows that AN has a risk of thermal runaway during storage, especially long-term storage or when some possible substances are mixed therein. This paper focuses on the effect of halides additives, such as sodium fluoride, sodium chloride, sodium bromide and sodium iodide, on the thermal decomposition products and energy release of AN. Especially, the thermal decomposition of AN added with 5% sodium halide and the evolved gases in the thermal decomposition process are investigated by C80 microcalorimetry and FTIR. The results show that all kinds of sodium halides have an effect on the thermal decomposition of AN, although these effects are different. The addition of the halide not only changes the timing of the formation of the AN thermal decomposition characteristic product, but also reduces the heat of the reaction. Combined with optimized kinetic parameters, the engineering prediction of thermal safety was carried out for each type of sample. It is found that sodium iodide is beneficial to the safety of large-scale storage of AN. The research results can provide a reference and guidance for revealing the thermal decomposition mechanism of halide-containing AN and thermal decomposition simulation of AN with additives.

Electrochemical synthesis of isobenzofuran-1-imines using oxidative halocyclization of o-alkynylbenzamides.

Electrochemical oxidative 5-exo-dig-oxo-halocyclization of o-alkynylbenzamides was achieved using readily available NaX (X = Cl, Br and I) salts under mild reaction conditions. The use of a cheap and highly stable sodium halide as a halide ion source is impressive for the synthesis of a variety of halogenated isobenzofuran-1-imines. This electrochemical protocol shows regioselectivity and excellent conversion to isobenzofuran-1-imines in good yields without the use of stoichiometric amounts of oxidants and transition metal catalysts.

Thermal behavior, solvatochromic parameters, and metal halide solvation of the novel water-based deep eutectic solvents

High viscosity of a deep eutectic solvent (DES) is one of the biggest challenges to their commercial use. In this study, two novel water-based low-viscosity DESs were formulated and could be easily applicable in many areas of research and industry, such as pharmaceuticals, waste management, and biorefinery. To formulate the DESs, water was used as a sole hydrogen bond donor, while the hydrogen bond acceptor was choline chloride. Melting points of 1:3 and 1:4 choline chloride: H2O were found to be significantly low, −79.21 and − 79.25 °C, respectively. TGA showed the stability of the DES over a wide temperature range. For example, in the TGA thermogram of 1:3 ChCl: H2O, was found to be crystalline up to 148.64 °C and the onset point was 193.75 °C. The solvent selectivity triangle from Kamlet-Taft parameters proved that the DESs possess similar solvatochromic properties to ionic liquids. Therefore, solvatochromism helped to understand the solvation of the DESs. A simple analytical method was developed employing ion chromatography and atomic absorption spectroscopy to investigate the solubility of sodium halides, alkali chlorides, and cobalt chloride in the studied DESs. Solubility trends of the metal halides in both DESs were NaCl > NaBr > NaI > NaF for sodium halides and LiCl > NaCl > KCl for alkali metal chlorides. Among all the studied metal halides, solubilities of the CoCl2 and LiCl were the highest. These findings indicate that the formulated DESs could be a good metal extraction media for the recycling process of spent Li-ion battery.

Surface Affinity of Alkali and Halide Ions in Their Aqueous Solution: Insight from Intrinsic Density Analysis.

The surface tension of all aqueous alkali halide solutions is higher than that of pure water. According to the Gibbs adsorption equation, this indicates a net depletion of these ions in the interfacial region. However, simulations and experiments show that large, soft ions, such as I-, can accumulate at the liquid/vapor interface. The presence of a loose hydration shell is usually considered to be the reason for this behavior. In this work, we perform computer simulations to characterize the liquid-vapor interface of aqueous alkali chloride and sodium halide solutions systematically, considering all ions from Li+ to Cs+ and from F- to I-. Using computational methods for the removal of surface fluctuations, we analyze the structure of the interface at a dramatically enhanced resolution, showing that the positive excess originates in the very first molecular layer and that the next 3-4 layers account for the net negative excess. With the help of a fictitious system with charge-inverted ion pairs, we also show that it is not possible to rationalize the surface affinity of ions in solutions in terms of the properties of anions and cations separately. Moreover, the surface excess is generally dominated by the smaller of the two ions.

Mechanochemical Metathesis between AgNO3 and NaX (X = Cl, Br, I) and Ag2XNO3 Double-Salt Formation.

Here we describe real-time, in situ monitoring of mechanochemical solid-state metathesis between silver nitrate and the entire series of sodium halides, on the basis of tandem powder X-ray diffraction and Raman spectroscopy monitoring. The mechanistic monitoring reveals that reactions of AgNO3 with NaX (X = Cl, Br, I) differ in reaction paths, with only the reaction with NaBr providing the NaNO3 and AgX products directly. The reaction with NaI revealed the presence of a novel, short-lived intermediate phase, while the reaction with NaCl progressed the slowest through the well-defined Ag2ClNO3 intermediate double salt. While the corresponding iodide and bromide double salts were not observed as intermediates, all three are readily prepared as pure compounds by milling equimolar mixtures of AgX and AgNO3. The in situ observation of reactive intermediates in these simple metathesis reactions reveals a surprising resemblance of reactions involving purely ionic components to those of molecular organic solids and cocrystals. This study demonstrates the potential of in situ reaction monitoring for mechanochemical reactions of ionic compounds as well as completes the application of these techniques to all major compound classes.

Generation of sodium halide endohedral metallofullerenes in the gas phase

Recent theoretical calculations show that ionic bond encapsulated endohedral metallofullerenes (EMFs) have great potential in the application of molecular electronic components. However, experimental study of these species is very limited, due to the difficulty in their generation. Thus, it is important to study the possibility and optimized conditions of these species generated in the gas phase. Mixtures of graphene and metal halides (MX), where M = Na, K; and X = Cl, Br, I, were used as the precursors for the experiments. Mass spectra were obtained in positive ion mode by laser irradiation of these mixtures of graphene and metal halides using a 7.0 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer equipped with a 355 nm YAG laser. EMF ions of NaCl@C+ 2n (2n = 120-244), NaBr@C+ 2n (2n = 110-240), and NaI@C+ 2n (2n = 116-198) were observed in the laser ablation mass spectra. However, the encapsulated ion could not be replaced by Li or K in these experiments, indicating that the effects of the metal cation on the EMFs are larger than those of halide anions. Ionic bond encapsulated EMF ions of NaX@C+ 2n (X = Cl, Br and I, 110 ≤ 2n ≤ 244) were generated by laser ablation of the mixture of graphene and sodium halides, but no species containing lithium or potassium were observed. This work opens the possibilities of using laser ablation for the synthesis of large-sized salt-encaged EMFs. Further study of the mechanism for these processes is important for the generation of the missing species.

Effect of Different Spectral Power Distributions on Mesopic Visual Performance with Blue Light-filtering Intraocular Lens

ABSTRACT The purpose of this work is to analyze the interaction between the spectral transmittance of old-aged subjects, before and after cataract surgery and blue light-filtering intraocular lens implantation, and the spectral power distribution of common street lamps, under conditions typical of nighttime driving. We analyzed contrast threshold and visual reaction time in off-axis vision at different mesopic illumination conditions provided by high-pressure sodium and metal halide lamps. Three groups of subjects with different spectral transmittances participated: young subjects as control group, old-aged subjects with senile cataracts and the same subjects after cataract surgery and blue light-filtering IOL implantation. A clear interaction appears between the spectral power distribution and the spectral transmittance, depending on the visual task. Transparent ocular media allow benefiting from the greater short-wavelength content of the halide lamp. However, cataracts increase contrast threshold and visual reaction time values and also affects how the spectral power distribution influences these visual tasks. After surgery and intraocular lens implantation, visual performance improves for both lamps and the blue light-filter seems to influence spectral transmittance, which affects visual performance under light provided by greater short-wavelength content lamps. Cataract surgery is responsible for an improvement in contrast threshold and visual reaction time tasks, though blue light-filtering of the intraocular lens seems to prevent the visual system from benefiting from lamps with greater emission at short wavelengths.

Flexible and free-standing polyvinyl alcohol-reduced graphene oxide-Cu2O/CuO thin films for electrochemical reduction of carbon dioxide

Flexible and free-standing thin films were fabricated and employed directly as working electrodes for the electrochemical reduction of CO2 in 0.5 N KHCO3 at 25 °C, in which, various sizes of Cu2O nanocubes (~ 27 ± 2, 37 ± 3, 62 ± 4 and 207 ± 3 nm) with different extent of surface oxidation (13, 20, 66, and 64% of Cu(II)) were reinforced on to polyvinyl alcohol/reduced graphene oxide matrix (PVA/rGO/(Cu2O/CuO_X, where, X = without halide, Cl, Br and I). The size of Cu2O nanocubes and their surface oxidation were systematically altered by the addition of 1 mL of 10 mM sodium halides (NaCl, NaBr, and NaI) during the synthesis. Energy-dispersive X-ray spectroscopy mapping displayed the specific adsorption of Cl− ions over the Cu2O surface, whereas Br− and I− ions did not show such behaviour. PVA/rGO/(Cu2O/CuO_Cl) thin film exhibited a low overpotential of 20 mV for CO2 reduction reaction and, ~ 60 and ~ 7 times higher current density at − 0.80 V vs. RHE compared to that of the PVA/rGO/(Cu2O/CuO), PVA/rGO/(Cu2O/CuO_Br) ≈ PVA/rGO/(Cu2O/CuO_I), respectively. Gas chromatography and 1H-NMR analyses confirmed methanol as the single liquid product, with a faradaic efficiency of 63% at − 0.75 V vs. RHE on PVA/rGO/(Cu2O/CuO_Cl) thin film.

Co-ion specific effect on sodium halides sorption and transport in a cross-linked poly(p-styrene sulfonate-co-divinylbenzene) for membrane applications

Sodium halide sorption and transport in a cation exchange membrane based on cross-linked poly(p-styrene sulfonate-co-divinylbenzene) (CR61) were investigated experimentally and theoretically. At fixed co-ion valence, sodium halide partitioning between aqueous electrolyte solutions and ion exchange polymers is only minimally sensitive to co-ion chemical identity. NaCl, NaF and NaI exhibit similar solubility coefficients in CR61, which agrees reasonably well with predictions of the Donnan-Manning model, especially at high external salt concentrations. Ion activity coefficients in the membrane were evaluated and ion sorption thermodynamics were investigated. Ion diffusion coefficients in CR61 were predicted using a recently developed framework based on the Manning diffusion model, which accounts for electrostatic effects on ion diffusion, and the Mackie-Meares model, which accounts for tortuosity/area effects on ion diffusion in swollen polymers. Model predictions agree reasonably well with the experimental data, especially at high external salt concentrations. The observed decrease in salt diffusion coefficients in CR61 relative to values in aqueous solutions is due primarily to tortuosity/area effects. Salt diffusion coefficients correlate with co-ion hydrated radius and membrane water content. Finally, salt permeability coefficients predicted using the solution-diffusion model exhibit good agreement with experimental data, especially at external salt concentration greater than 0.1 mol/L.

Hydrogen halide-free synthesis of organohalides for organometal trihalide perovskite solar cells

We report an environmentally benign and economical approach for the large-scale production of methylammonium halides (MAX, X=I or Br) and formamidinium halides (FAX, X=I or Br) as core materials in perovskite solar cells (PSCs), which have emerged as the most promising sustainable energy source. In contrast to conventional processes that use highly toxic HI and HBr, ion exchange between sodium halide (NaX) and methlyammonium chloride (MACl) or formamidinium chloride (FACl) was found to be highly suitable for mass production. The average reaction yields of the ion-exchange process were comparable to that of the HX synthesis route: 98.8% for MAI, 98.7% for MABr, 98.0% for FAI, and 98.9% for FABr. The purity of the prepared samples was analyzed by various spectroscopic methods. Finally, a perovskite solar cell was fabricated with MAI prepared by ion-exchange reaction. The power conversion efficiency, which was measured to support the industrial feasibility of the method, was found to be similar to that of a device fabricated with commercial MAI.

Electrochemically Induced Facile and Efficient Multicomponent Approach to Medicinally Relevant 4‐[4‐oxo‐4H‐pyran‐2‐yl](aryl)‐methylisoxazol‐5(2H)‐one Scaffold

AbstractThe new electrochemically induced multicomponent assembling has been accomplished: the electrocatalytic transformation of aldehydes, 3‐aryl‐substituted isoxazol‐5(4H)‐ones and kojic acid has been carried out in alcohols in an undivided cellin the presence of sodium halides. This transformation proceeds with the selective formation of the earlier unknown substituted 4‐{[3‐hydroxy‐6‐(hydroxymethyl)‐4‐oxo‐4H‐pyran‐2‐yl]‐(aryl)methyl}‐isoxazol‐5(2H)‐ones in 57–93 % yields with 190–310 % current efficiency. This new electrocatalytic process provides a facile and efficient way to the separated by C‐aryl‐substituted spacer 3‐arylisoxazol‐5(4H)‐one and kojic acid pharmacology active heterocyclic fragments, which are promising compounds for different biomedical applications, and, in particular, for regulation of inflammatory as was shown by docking studies in this research.

Epipolythiodiketopiperazine and trichothecene derivatives from the NaI-containing fermentation of marine-derived Trichoderma cf. brevicompactum.

The marine-derived fungus Trichoderma sp. TPU199 (cf. Trichoderma brevicompactum) produces pretrichodermamide A (1) and gliovirin (2), which possess a rare type of epipolythiodiketopiperazine (ETP) structure with a disulfide bridge between the α- and β-positions of two amino acid residues. We previously reported that this strain gave the halogenated ETPs, DC1149B (4), DC1149R (6), and iododithiobrevamide (7), when fermented with sodium halides (NaCl, NaBr, and NaI). Further analyses of the metabolites obtained under NaI-containing culture conditions resulted in the isolation of two new ETP derivatives (11 and 12) and three new trichothecene sesquiterpenes (13-15). The structures of 11 and 12, including their absolute configurations, were elucidated based on spectroscopic data for 11 and 12 and comparisons with those for 1 and related compounds, revealing that 11 was an epimer of 1 at the C-5 position and 12 was a trithio-derivative of 11. The structures of 13-15 were established by analyzing their 1D and 2D NMR data. The absolute configurations of 13-15 were assigned by comparing their experimental electronic circular dichroism (ECD) spectra with the calculated ECD spectrum of 13.

Copper‐Catalyzed sp3‐Carbon Radical/Halogen Radical Cross Coupling: Selective Halogenation of 1,3‐Dicarbonyl Compounds

AbstractA new copper‐catalyzed sp3‐carbon radical/halogen radical cross‐coupling strategy for the formation of C(sp3)‐X bond is described. This provides a general method for synthesis of α‐halogenated and α,α‐dihalogenated‐1,3‐dicarbonyl compounds using sodium halides as halogen source under mild conditions.

Effects of Halide Anions on the Solution Behavior of Double Hydrophilic Carboxy-Sulfobetaine Block Copolymers.

The solution behavior of the double polybetaine block copolymer poly(2-((2-(methacryloyloxy)ethyl)dimethylammonio)acetate)-block-poly(3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate (PGLBT-b-PSPE) in sodium halide aqueous solutions was investigated. In the presence of salt ions, the unimer-to-micelle transition of PGLBT-b-PSPE that originated by Coulombic attraction between PSPE motifs was suppressed and shifted to much lower temperatures. The transition was hindered more by increases in the salt concentration because of additional counterion binding on the ionized site of PGLBT-b-PSPE chains, which screens the dipole-dipole attractions. The specific ion effect was investigated on four different halides, Cl-, Br-, I-, and F-. Cl- and two chaotropes (Br- and I-) apparently prevented micelle formation, and the hindering effectiveness on the PSPE pairing followed the general Hofmeister series of anions: I- > Br- > Cl-. More chaotropic anions strongly maintained the polymer chains in a fully hydrated state when the same amount of salts was incorporated. However, F-, which is classified as a kosmotrope, only made a small contribution to lowering the transition point and led to abrupt transition without showing a gradual phase change prior to the transition. The variations of hydrodynamic radius and zeta potentials of unimers and micelles gave hints of the solvation state of salt-incorporated PGLBT-b-PSPEs in each state. These results suggest that chaotropic halides tend to exist in the vicinity of the diblock polybetaine chain surface and thus prominently influenced the thermoresponsive solution behavior, whereas kosmotropic F- prefers water molecules and causes minor changes in the PGLBT-b-PSPE aqueous solution.

Yttrium-Sodium Halides as Promising Solid-State Electrolytes with High Ionic Conductivity and Stability for Na-Ion Batteries.

All-solid-state sodium-ion batteries (ASIBs) are promising candidates for large-scale energy storage applications. To build such a battery system, efficient solid-state electrolytes (SSEs) with high sodium ionic conductivity at room temperature and good electrochemical stability as well as interface compatibility are required. In this work, using density functional theory combined with molecular dynamics simulation and a phase diagram, we have studied the potential of yttrium halide-based materials (Na3YX6, where X = Cl or Br) with inherent cation vacancies as diffusion carriers for solid electrolytes in ASIBs. A great balance between electrochemical stability and ionic conductivity found in these two systems overcomes the shortcomings of sulfide- and oxide-based SSEs. In particular, these two materials show Na+ conductivities of 0.77 and 0.44 mS cm-1 at 300 K and wide electrochemical windows of 0.51-3.75 and 0.57-3.36 V, and good interfacial stability with Na metal anode and high-potential polyanion (fluoro)phosphate cathode materials, respectively. These features make halide-based materials promising efficient solid-state electrolytes for Na-ion batteries.

Electrochemically induced multicomponent ‘one-pot’ assembling benzaldehydes, N,N′-dimethylbarbituric acid, and kojic acid

The new electrochemically induced multicomponent assembling was found: the electrocatalytic transformation of benzaldehydes, N,N′-dimethylbarbituric acid, and kojic acid has been carried out in alcohols in an undivided cell in the presence of sodium halides with the selective formation of the earlier unknown substituted 5-[[3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl](phenyl)methyl]-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-triones in 65–88% yields and with 325–440% current efficiency. This new multicomponent process provides facile and efficient way to the novel type of separated by C-aryl-substituted spacer both 4-oxo-4H-pyran and 1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione pharmacology active systems, which are promising compounds for different biomedical applications.

Composition and Solubilization of the Microemulsion Systems Containing Triton X-100: Effects of Aqueous Composition and Oil-Water-Ratios

Abstract The composition and solubilization of the optimum microemulsion systems containing Triton X-100/pentan-1-ol/aliphatic hydrocarbon/water were studied with the ∊-β fishlike phase diagram method. The solubilities of the alkanol (S A), the mass fractions of the alkanol in the interfacial layer (AS ) and the optimum solubilization parameters (SP∗) of the microemulsion systems with different aqueous phases (salt, acid, alkali) and with different α values were obtained and discussed. The SP∗ values increase significantly with the cation radius of the chlorides (NaCl, KCl, CsCl), but decrease slightly with the anion radius of the sodium halides (NaCl, NaBr, NaI). However, SP∗ values decrease with the increased salinities and NaOH contents. The trend was reversed for the acid systems. When the oil-water ratio (α) increases, the S A and A S values significantly increase, while the SP∗ values increase slowly. As the length of the carbon chain of the alkane molecules increases, both the S A and A S values increase, while the SP∗ values decrease significantly.