Type Of Anion Research Articles

Computational Investigation of MAX as Intercalation Host for Rechargeable Aluminum‐Ion Battery

AbstractLayered carbides and their analogs with MAX phase (general formula AMn+1Xn) have emerged as promising candidates for energy storage and conversion applications. One frontier for energy storage is using MAX as an Al‐ion intercalation electrode. Given that many MAXs have Al as the A sites, the structure can potentially serve as a stable host for Al intercalation. Here in this work, 425 ternary MAX Al‐ion battery electrodes are computationally enumerated. Specifically, first principal phase diagram calculations are performed on the combinatorial space of 17 types of typical transition metals, five types of anions (C, N, B, Si, and P), three types of stoichiometries (n = 1, 2, and 3) and two types of layered stackings (α and β). Among all the ternary MAX materials, 44 candidates show reasonable synthetic accessibility, and six with extraordinary performance are predicted to be promising Al‐ion battery electrodes. With the phase stability, and electrochemical performance (average voltage, theoretical capacity, energy density, and Al diffusion barrier), the work provides a comprehensive computational assessment of the great opportunities behind MAX‐based Al‐ion batteries.

LANTHANIDE CONTRACTION IN CHELATES OF ETHYLENEDIAMINETETRAACETIC ACID BASED ON CRYSTALLOGRAPHIC DATA: A SHORT REVIEW

The lanthanide (Ln) series has been attracted so much attention not only for its physical properties but also for its applications in organic synthesis and biomedical engineering. In the lanthanide chemistry, lanthanide contraction is a crucial concept meaning the gradual decrease in ionic radii as the atomic number of the Ln series increases. As a prominent chelator, ethylenediaminetetraacetic acid (EDTA) has been well-known to give stable complexes with various metals including Ln ions, resulted in forming (EDTA−4H)4− anion by deprotonation; over 100 kinds of Ln-EDTA complexes have hitherto been synthesized and structurally characterized using X-ray crystallography. While the lanthanide contraction phenomenon has been extensively studied in certain complexes of Ln, systematization on the Ln-EDTA remains inadequate though the chelates of EDTA are commonly used. Thus, this study presents a comprehensive analysis based on the data from the Cambridge Crystallographic Data Centre (CCDC). In mononuclear EDTA complexes X[Ln(EDTA−4H)(H2O)m]·nH2O (X+ = NH4+and its analogues) systematic lanthanide contraction depending on their coordination number are presented except for a few cases. However, in the case of non-mononuclear complexes or coordination polymers, the compositions become more complicated, and a greater variation in atomic bond length occurs, which is unusual for the lanthanide contraction studies in previous research. These varieties are considered to be influenced by different types of counter-cations, inorganic anions, solvent molecules and bridging O atoms from another EDTA anions. This suggests the flexibility and versatility of EDTA as a ligand. Such findings in the Ln-EDTA complexes could potentially provide us further development of a novel function in the future.

Effects of alkyl chain length and halide anion on hydrogen bonding, electrochemical transport properties and double layer capacitance in eutectic solvents

Eutectic solvents (ESs) have been widely studied due to their tunable solvation and physical properties. The properties of eutectic solvents that are formed from mixtures of hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) are governed by a complex hydrogen (H) bonded network among their constituents. However, an understanding of the key factors effecting the H-bonding structure and dynamics, and the resulting physical and electrochemical properties at interfaces is still in its infancy. In this study, the influence of the cation’s alkyl chain length and the anion chemical identity on the characteristics of the H-bonding network in eutectic solvents were examined. In particular, ESs formed from mixtures of tetraalkylammonium salts as HBAs and ethylene glycol as the HBD were studied. Complementary spectroscopic studies revealed the changes in the solvation environment as a function of the ammonium chain length (C1, C2, C3, and C4) and the anion type (Cl−, Br−, I−). With an increase in the alkyl chain length or a decrease in the electronegativity of halide anions (X−), it was found that the O–H bond length shortens and the H···X− bond elongates in the H-bond (O–H···X−) structure, thus resulting in an increase of the solvated ion size and a decrease in the bulk ionic conductivity. Further, double layer capacitance measurements showed that increased capacitance was correlated with shorter H-bonds in anion solvates.

Designing V2O5/MXene van der Waals heterostructure for complementary electrochromic dual-ion capacitor

Developing highly efficient electrochromic energy storage device (EESD) is desirable for yielding ample color variation and large electrochemical capacity from the viewpoint of practical energy-saving. However, only a single type of cation or anion traveled back and forth between the cathode and anode in conventional electrochromic devices (ECDs) results in low coloration efficiency and long switching time. Herein, for the first time, we designed a multicolor complementary electrochromic dual-ion capacitor (EDIC) based on ion insertion/extraction and doping/de-doping of the anodic and cathodic electrochromic materials, respectively, to realize the fast faradic reaction and rich color variation. Significantly, the prepared V2O5/MXene van der Waals heterostructure with improved conductivity and more “active” sites favors the charge transfer, effectively improving the switching speed and coloration efficiency. Since the excellent ion matching and synergy effect of Li+ insertion/extraction in V2O5/MXene anode and ClO4- doping/de-doping at PANI/TiO2 cathode, the complementary EDIC exhibits significant color changes, large optical modulation (51%), short switching time (2.4/7.2 s) and high coloration efficiency (111 cm2 C−1), which is much superior to traditional V2O5-based ECDs. We believe that this work provides a general strategy for building a complementary EDIC with excellent electrochromic and energy storage performances.

Preparation of ionic liquid stationary phase copolymerized with anion and cation for mixed-mode liquid chromatography

Ionic liquids (ILs) are a promising material to develop stationary phases for mixed-mode chromatography (MMC). In order to investigate the effect of anion type and polymerization method of ionic liquid, this work prepared and compared two stationary phases (Sil-IM-Br and Sil-IM-SAG) based on the polymeric ionic liquid, one of which copolymerized cation and anion. Two stationary phases were characterized and provided satisfactory retention repeatability (RSD < 0.3 %) and column efficiency (84600 plates/m). Chromatographic conditions (ACN content, salt concentration, and pH) were varied to reveal the retention characters and interactions between stationary phases and solutes. The results showed that both two developed stationary phases can operate under the mixed mode of RPLC/HILIC/IEC, but diverse selectivity was provided. So, the retention mechanisms were studied by linear solvation energy relationship equation (LSER) and thermodynamic research. Two stationary phases showed totally different retention towards carboxylic acids, which resulted from the effect of anion bonded. Lastly, the developed stationary phases were applied to separate alkylbenzenes and polycyclic aromatic hydrocarbons (PAHs) under RPLC. Furthermore, 7 carboxylic acids and 7 nucleosides and bases and complex samples were successfully separated under HILIC mode, Sil-IM-Br and Sil-IM-SAG provide better performances and different selectivity when compared with commercial mixed-mode columns. This work proves that cationic and anionic copolymerization provides a new method for stationary phase design, and better selectivity can be obtained by changing the anions.

Synthesis and Physicochemical Properties of Yttrium Subgroup REE Lactates Ln(C3H5O3)3·2H2O (Ln = Y, Tb–Lu)

A series of yttrium subgroup rare earth elements (REE) lactates of [Ln(C3H5O3)3(H2O)2] (Ln = Tb–Lu) composition isostructural to yttrium lactate has been prepared for the first time. Synthesis of crystalline REE lactates has been performed from solutions of REE nitrates in the presence of L-lactic acid and hexamethylenetetramine. The composition and structure of the obtained compounds have been confirmed by X-ray powder diffraction, thermal, and chemical (CHN) analysis. The coordination type of lactate anions to REE cations has been determined by IR spectroscopy. Thermal decomposition of REE lactates at 800°C leads to formation of nanocrystalline (20–40 nm) REE (Y, Tb–Lu) oxides.

The effect of anionic surfactant type and concentration on the development of waterborne nitrocellulose

To better understand the gel emulsification method as an efficient method for producing waterborne nitrocellulose coatings [1–3], the effect of anionic surfactant type (sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS)) and concentration on the emulsification process was investigated. In the case of using SDBS, it was not possible to produce nitrocellulose emulsion via the gel emulsification method while emulsions with submicron size were produced using SDS. Contrary to what might be thought, in the gel emulsification method, high surfactant concentrations did not contribute to better drop breakage and led to catastrophic phase inversion. In addition, increasing surfactant concentration increased the hydrophilicity of the final coatings and decreased their chemical and mechanical properties.

Organometallic Allene [(μ-C)(Fe(CO)4 )2 ]: Bridging Carbon Showing Transformation from Classical Electron-Sharing Bonding to Double σ-Donor and Double π-Acceptor Ligation.

Allenes (R2 C=C=CR2 ) have been traditionally perceived to feature localized orthogonal π-bonds between the carbon centres. We have carried out quantum-mechanical studies of the organometallic allenes envisioned by the isolobal replacement of the terminal CH2 groups by the d8 Fe(CO)4 fragment. Our studies have identified two organometallic allenes viz. D2d symmetric [(μ-C)(Fe(CO)4 )2 ] (2) and D3 symmetric [(μ-C)(Fe(CO)4 )2 ] (3) with trigonal bipyramidal coordination at the Fe atoms. Compound 2 features the bridging carbon atom in an equatorial position with respect to the ligands on the TM centre, while 3 features the central carbon atom in an axial position. The bis-pseudoallylic anionic delocalisation proposed in the C2-C1-C3 spine of organic allene is retained in the organometallic allene 2, and is transformed to a typical three-centre bis-allylic anionic delocalisation in the organometallic allene 3. The topological analysis of electron density also indicates a bis-allylic anionic type delocalisation in the organometallic allenes. The quantitative bonding analysis using the EDA-NOCV method suggests a transition from classical electron-sharing bonding between the central carbon atom and the terminal groups in 1 to donor-acceptor bonding in 3. Meanwhile, both electron-sharing and donor-acceptor bonding models are found to be probable heuristic bonding representations in the organometallic allene 2.

Probing Acid-Induced Compaction of Denatured Proteins by High-Pressure Electrospray Mass Spectrometry.

Further increase in the acidity in the most denaturing acidic solution is known to induce compaction of the fully unfolded protein into a compact molten globule. The phenomenon of "acid-induced folding of proteins" takes place at pH ∼1 in strong acid aqueous solutions with high electrical conductivity and surface tension, a condition that is difficult to handle using conventional electrospray ionization methods for mass spectrometry. Here, high-pressure electrospray ionization (HP-ESI) is used to produce well-resolved mass spectra for proteins in strong acids with pH as low as 1. The compaction of protein conformation is indicated by a large shift in the charge state from high charges to native-like low charges. The addition of salt to the protein in the most denaturing condition also reproduces the compaction effect, thereby supporting the role of anions in this phenomenon. Similar compaction of proteins is also observed in organic solvent/acid mixtures. The charge state of the compacted protein depends on the type of anions that formed ion pairs with a positive charge on the protein. The dissociation of ion pairs during the ionization process forms neutral acids that can be observed by HP-ESI using a soft ion introduction configuration.

A structural comparison of salt forms of dopamine with the structures of other phenylethylamines.

The structures of four salt forms of dopamine are reported. These are dopamine [2-(3,4-dihydroxyphenyl)ethan-1-aminium] benzoate, C8H12NO2+·C7H5O2-, I, dopamine 4-nitrobenzoate, C8H12NO2+·C7H4NO4-, II, dopamine ethanedisulfonate, 2C8H12NO2+·C2H4O6S22-, III, and dopamine 4-hydroxybenzenesulfonate monohydrate, C8H12NO2+·C6H5O4S-·H2O, IV. In all four structures, the dopamine cation adopts an extended conformation. Intermolecular interaction motifs that are common in the salt forms of tyramine can be found in related dopamine structures, but hydrogen bonding in the dopamine structures appear to be more variable and less predictable than for tyramine. Packing analysis discovered three dopamine-containing groups of structures that can be described as isostructural with regards to the cation positions. Two of these groups contain both dopamine and tyramine species, and one of these is also highly variable in other ways too, containing anhydrous and hydrated forms, different anion types and ionized and neutral phenylethylamine species. As such, the group illustrates that packing behaviour can be robust and similar even where intermolecular interactions such as hydrogen bonds are very different.

A dynamic database of solid-state electrolyte (DDSE) picturing all-solid-state batteries

All-solid-state batteries (ASSBs) are a class of safer and higher-energy-density materials compared to conventional devices, from which solid-state electrolytes (SSEs) are their essential components. To date, investigations to search for high ion-conducting solid-state electrolytes have attracted broad concern. However, obtaining SSEs with high ionic conductivity is challenging due to the complex structural information and the less-explored structure-performance relationship. To provide a solution to these challenges, developing a database containing typical SSEs from available experimental reports would be a new avenue to understand the structure-performance relationships and find out new design guidelines for reasonable SSEs. Herein, a dynamic experimental database containing >600 materials was developed in a wide range of temperatures (132.40–1261.60 ​K), including mono- and divalent cations (e.g., Li+, Na+, K+, Ag+, Ca2+, Mg2+, and Zn2+) and various types of anions (e.g., halide, hydride, sulfide, and oxide). Data-mining was conducted to explore the relationships among different variates (e.g., transport ion, composition, activation energy, and conductivity). Overall, we expect that this database can provide essential guidelines for the design and development of high-performance SSEs in ASSB applications. This database is dynamically updated, which can be accessed via our open-source online system.

Comparative study on the physicochemical properties of N-SO3H functionalized ammonium and imidazolium ionic liquids

Twelve N-SO3H functionalised ammonium and imidazolium based Brønsted acidic ionic liquids were synthesised by varying four anions (Cl-, CF3COO-, BF4- and OTf-). They were characterised using various spectroscopic techniques. A detailed study on Brønsted acidity, thermal stability, conductivity, density, polarity, and electrochemical window of the ionic liquids (ILs) was carried out to analyse the effects of different cations and anions. The conductivity of these ILs in molecular solvents (MeOH, MeCN and acetone) were measured at a particular mole fraction (XIL = 0.001) of the ILs and the results were correlated with Kamlet-Taft solvatochromic parameters (ETN, α, β) of the solvents. Their Brønsted acidity order was determined using the Hammett plots. The polar nature of synthesized ionic liquids was studied by taking fluorescence emission spectrum of pyrene as a probe molecule in two illustrative 2-ethyl-1,3-disulfoimidazolium ionic liquids. The electrochemical stabilities of twelve ILs in the same molecular solvents were determined by Cyclic Voltammetry. The results revealed highest electrochemical stability window for the imidazolium ILs in acetone. Among the four types of anions, the ionic liquids of CF3COO- and Cl- anions were found to be thermally stable up to 250–260 °C as compared to the ionic liquids of BF4- and OTf- anions.

Effects of Surfactants on the Chemical Mechanical Polishing Performance of a-Plane Sapphire Substrates

The effects of four different types of surfactants, cetyltrimethylammonium bromide (CTAB, cationic type), sodium dodecyl benzene sulfonate (SDBS, anion type), N-Laurylaminoacetic acid (NL, amphoteric type) and primary alcohol ethoxylate (AEO, non-ionic type), on the chemical mechanical polishing (CMP) performance of a-plane sapphire substrates in the range of pH 6–12 were investigated using colloidal silica as abrasive particles. The results demonstrated that cationic surfactants promoted the material removal of the sapphire substrate in the range of pH 9–12, while anionic, amphoteric, and non-ionic surfactants inhibited the material removal of the sapphire substrate in the range of pH 6–10. The mechanism of material removal in sapphire CMP was discussed through AFM observations, zeta potential measurements, particle size distribution tests, and friction behavior analysis.

Transport properties of imidazolium-based room temperature ionic liquids in confinement of slit charged carbon nanopores: New insights from molecular simulations

The paper presents a study of the behavior of room-temperature ionic liquids with different alkyl chain lengths and anion types in slit negatively charged carbon nanopores of various widths (1–15 nm) using all-atom molecular dynamics simulations. The structure of the confined ionic liquids is investigated using number, mass, and charge density profiles and radial distribution functions. The paper also discusses such characteristics as mean squared displacement of ions in all directions, self-diffusion coefficients of cations and anions in the bulk, their temperature dependences, electrical conductivity. Some energy characteristics are obtained by quantum chemical calculations. It is established that there is a bulk region in the pore center for all the confined ionic liquids, starting from the pore width of 7 nm. The sums of the cationic and anionic self-diffusion coefficients of different ionic liquids can be arranged as follows: D[OMIM][BF4] < D[EMIM][BF4] < D[OMIM][NTf2] < D[EMIM][NTf2]. Due to layering structure inside the pore, the dynamics of the ions is heterogeneous. It is shown that the RTILs with longer alkyl chains have lower electrical conductivities regardless of temperature. The opposite effect associated with the species size is observed for RTILs with different anions.

Imidazolinium Salts for the Carbonates Production from CO2 and Epoxides

Novel imidazolinium based materials were prepared by modification of MCM-41 and characterized by elemental analysis, nitrogen sorption, thermogravimetric analysis, UV–Vis, and X‑ray diffraction. The materials differed in the alkyl, or halide used (MeI, EtBr, PrI, BuBr, BuCl, and BnBr). The characterization methods confirmed the successful formation of desired materials containing iodide and bromide. In this research, the materials were examined as catalysts for the cycloaddition of carbon dioxide to styrene oxide to produce styrene carbonate. The influence of anion type and the length of the alkyl chain in the salt was discussed. The results show imidazolinium materials as efficient heterogeneous catalysts for the model reaction. Styrene carbonate was prepared with high selectivities in all cases. The highest conversion of styrene oxide (95%) was achieved using a material containing iodomethane (MCM-Im-MeI) under the following conditions: 1.2 MPa, 120 °C, solvent free. The catalysts were successfully reused without a significant decrease of their activity.Graphical

Revealing Local Structure and Dynamics in Li-Salt Electrolytes Using Dielectric Relaxation Spectroscopy

Understanding the interplay between local structure and dynamics is critical for establishing design rules for advanced ion-conducting electrolytes. In this work, a set of Li-salt in liquid electrolytes is studied using dielectric relaxation spectroscopy (DRS) to examine correlations between several electrolyte properties, including conductivity, dielectric relaxation time and strength, ionicity, and viscosity. These properties were evaluated by changing ion concentration, solvent type, and anion type. DRS was used to identify relaxation processes associated with the solvent and different ion-solvent coordinating structures, and the dielectric properties are reported for the first time for a majority of these systems. The behavior of viscosity and conductivity were shown to change similarly with concentration when accounting for the local coordinating environment, regardless of the salt or solvent type. τα, the dielectric relaxation time of the solvent-ion complexes, is shown to be independent of ion content at low salt concentrations, when solvent separated ion pairs are the dominant ion-solvent complex. However, at high ion concentrations, a new relationship, a power-law dependence, was identified between molar conductivity and τα, as well as viscosity and τα, demonstrating that the dependence of molar conductivity or viscosity on τα is controlled in part by the solvent type, due to variation in shielding between contact ion pairs and aggregates. In contrast, there was not a clear change in the dependence of molar conductivity or viscosity on τα with changing anion. Furthermore, the effective dipole moments of the ion-solvent complexes were determined, and found to decrease with increasing ion concentration, as contact ion pairs and aggregates form. This systematic analysis of the wide range of Li-salts and solvents, and discussion of relations between different local structures and dynamic processes that contribute to conductivity, helps lay a foundation for the design of new liquid electrolytes.

Influence of temperature and anion type on thermophysical properties of aqueous solutions of morpholine based amino acid ionic liquids

Densities and sound velocities of aqueous solutions of N-butyl-N-methylmorpholine based amino acid ionic liquids (AAILs), including N-acetyl-L-alanine, N-acetyl-L-valinate, N-acetyl-L-leucinate, and N-acetyl-L-izoleucinate anions were measured at a temperature from 293.15 to 313.15 K at 5 K intervals and atmospheric pressure. These data were used to calculate the apparent molar volumes and the apparent molar compressibilities in the concentration range of (0.02 to 0.3) mol.kg−1. Infinite dilution values for the volumetric and acoustic properties were evaluated by an extrapolation procedure based on Redlich – Meyer type equations. The limiting apparent molar expansibility coefficients were also obtained from the slopes of the apparent molar volume at infinite dilution versus temperature. Using the Passynski method, the hydration numbers for AAILs in an aqueous medium were calculated. The results indicate that in the studied solutions, the ion–solvent interactions are determined by the hydrophobic effect, which results in the decrease of the limiting apparent molar compressibilities and an increase of limiting apparent molar expansibility coefficients in the order: [Mor1,4][N-Ac-L-Ala], [Mor1,4][N-Ac-L-Val], [Mor1,4][N-Ac-L-Leu], [Mor1,4][N-Ac-L-Izoleu]. The empirical slopes in Redlich –Rosenfeld – Meyer equations show that the hydrophobicity of amino acid anions is also responsible for the ion-ion interactions.

Progress in Manipulating Dynamic Surface Reconstruction via Anion Modulation for Electrocatalytic Water Oxidation.

The development of efficient and economical electrocatalysts for oxygen evolution reaction (OER) is of paramount importance for the sustainable production of renewable fuels and energy storage systems; however, the sluggish OER kinetics involving multistep four proton-coupled electron transfer hampers progress in these systems. Fortunately, surface reconstruction offers promising potential to improve OER catalyst design. Anion modulation plays a crucial role in controlling the extent of surface reconstruction and positively persuading the reconstructed species' performances. This review starts by providing a general explanation of how various types of anions can trigger dynamic surface reconstruction and create different combinations with pre-catalysts. Next, the influences of anion modulation on manipulating the surface dynamic reconstruction process are discussed based on the in situ advanced characterization techniques. Furthermore, various effects of survived anionic groups in reconstructed species on water oxidation activity are further discussed. Finally, the challenges and prospects for the future development directions of anion modulation for redirecting dynamic surface reconstruction to construct highly efficient and practical catalysts for water oxidation are proposed.

Reliable Identification of Relevant Factors for the Reactive Extraction of Succinic Acid from Electrolyte Containing Solutions

ABSTRACT Reactive extraction of succinic acid by tertiary amines is an effective separation technique. Its potential application for the initial recovery of bio-based succinic acid from fermentation broth. However, the co-extraction of inorganic anions significantly impairs the extraction performance. In this study, we use a statistically backed design of experiments method (DoE) to screen and identify the factors with a significant effect and relevant impact on extraction yield and selectivity. Eight operational factors (Extractant, solvent, succinic acid concentration, amine concentration, initial pH, the type of anion, electrolyte concentration, and temperature) were screened by applying an orthogonal design plan for the experiments. The choice of the extractant and diluent as well as the type of anion had the most significant effect on the extraction yield. In contrast, the selectivity was mainly affected by the concentration ratios of succinic acid and electrolyte. The screening plan reduced the number of experiments from 1728 possible combinations to 72 experiments required to identify the factors while maintaining the significance of the identified effects. We suggest competing mass-action relationships between the pH-dependent protonation of amines and the complexation of succinic acid to explain the observed trends.

Assessment of the Antibacterial Potential of Layered Double Hydroxides

Microbes play a crucial role in our lives, and certain pathogenic bacteria are responsible for a wide range of infectious illnesses, food safety, and environmental damage. Layered double hydroxide (LDH), a type of natural two-dimensional substance with a distinctive layered structure also known as anionic clays, has been established as a material that may be utilized to battle a variety of bacterial infections. The interesting properties of LDH include their ease of synthesis, unique structure, uniform distribution of different metal cations in the brucite layer, surface hydroxyl groups, flexible tunability, intercalated anions with interlayer spaces, swelling properties, oxo-bridged linkage, and high chemical and thermal stability, ability to intercalate different types of anions (inorganic, organic, biomolecules, and even genes), delivery of intercalated anions. In the field of biomaterials, LDH has gained prominence as a significant class of layered materials with promising applications. Here, emphasis has been placed on factors such as biocompatibility, anion exchange with the target ion, holding of guest species in the interlayer space, and controlled anion release in a given medium. By utilizing LDH's inherent biocompatibility, several studies have improved its antibacterial characteristics, enabling researchers to add active substances into its matrix for the treatment of bacterial-caused disease. Despite the fact that LDH's antibacterial capabilities have been the subject of several studies, there are currently very few reviews of such findings. Therefore, this study reviewed current developments in new LDH techniques to enhance their antimicrobial activity and provided background on their structures.