Search Results (101)

Aqueous zinc–iodine batteries (AZIBs) are emerging as highly promising candidates for next-generation, grid-scale energy storage due to the intrinsic safety of water-based electrolytes, the high theoretical capacity of the zinc anode, and the rapid conversion kinetics of the iodine cathode. However, the practical commercialization of AZIBs is severely impeded by formidable interfacial instabilities, including the uncontrollable growth of zinc dendrites, parasitic hydrogen evolution reactions (HER), and the notorious polyiodide (I₃⁻, I₅⁻) shuttle effect. These macroscopic degradation modes are fundamentally rooted in the robust [Zn(H₂O)₆]²⁺ primary solvation sheath and the immense thermodynamic driving force for polyiodide dissolution in highly polar aqueous media. To address these interconnected challenges, electrolyte engineering has evolved into the most potent, holistic strategy. This comprehensive review systematically evaluates the latest advancements in electrolyte engineering for AZIBs. We first deeply decipher the fundamental thermodynamic mechanisms governing Zn²⁺ desolvation and iodine multiphase conversion. Subsequently, we critically analyze cutting-edge regulation paradigms, including water-in-salt (WIS) and localized high-concentration electrolytes (LHCE), cosolvent networks, functional molecular additives, deep eutectic solvents (DES), and quasi-solid-state hydrogels. By integrating in situ/operando spectroscopic characterizations with multiscale theoretical computations (such as MD and DFT), we elucidate the structure–activity relationships at the atomic level. Finally, we provide strategic perspectives on the future trajectories of the field, emphasizing the stabilization of multi-electron (I⁻/I⁰/I⁺) halogen chemistry, AI-driven high-throughput screening, and the rigorous standardization of Ah-level pouch cell engineering for extreme-environment applications. Full article

Sialic acids are a diverse class of widely distributed monosaccharides that are engaged in a wide range of biological processes. Sialin, a sialic acid/proton symporter, transports sialic acid across membranes between the lysosomal lumen and cytosol, playing a critical role in sialin metabolism. Taking advantage of recently published experimental structures of sialin, we report here the first computational study that probes the molecular mechanism of ligand transport through sialin, which is yet to be fully understood. In particular, we carry out steered molecular dynamics simulations of the transport of N-acetylneuraminic acid, the most widely spread natural derivative of sialic acids, through sialin with two key glutamate residues (E171 and E175) in various protonation states. The previously proposed model is refined with enriched atomistic details from this study for the cotransport of sialic acid and proton. With additional quantum calculations, our data suggest a possible explanation for why mutation R168A retains most of the transport activities, but R168K does not. Full article

Three multicomponent crystals of metformin were investigated to elucidate factors governing crystal architecture. Structures were determined by X-ray diffraction and analyzed using the Atoms-in-Molecules (AIM) approach, focusing on critical points and electron density topology. Three types of crystals were obtained: salt, cocrystal salt solvate and mixed salt with both organic and inorganic anions. Protonation of nitrogen atoms in metformin alters bond lengths and electron density, while strong intramolecular hydrogen bonds in hydrogenmaleate anions stabilize the structures and define the preferred anion geometry. Comparison with monoprotonated metformin revealed similar topological features despite differing protonation states. Mechanochemical synthesis via liquid-assisted grinding (LAG) enabled selective formation of specific crystalline forms, with the solvent type and acid polymorph influencing product distribution. These results highlight the critical roles of protonation, hydrogen bonding, and synthetic methodology in designing and controlling multicomponent metformin crystal structures. Full article

Nitronyl nitroxides (NNs) are widely employed in chemistry, physics, and materials science due to their inherently high stability and magnetic properties. However, the synthesis of C(2)-organoelement derivatives remains a challenging task. This paper reports on the efficient synthesis and characterization of an unusual organosilver complex consisting of the [Ag–(IPr)₂]⁺ cation and the [Ag–(NN)₂]⁻ anion. The salt [Ag–(IPr)₂][Ag–(NN)₂] was prepared in high yields (88–96%) by two synthetic routes: by reacting the carbene ligand precursor IPr·HCl with Ag₂O and nitronyl nitroxide NN–H, or by addition of NN–H/^tBuONa to a THF solution of IPrAgCl (generated in situ from IPr·HCl and Ag₂O) under microwave irradiation. Electrochemical analysis of [Ag–(IPr)₂][Ag–(NN)₂] revealed a reversible one-electron oxidation peak at E_1/2 = −0.258 V and an irreversible reduction peak at E_p = −2.169 V, which is likely related to the electrochemical transformation of the nitronyl nitroxide moieties. Crystallization from an acetone/benzene solution yielded crystals of [Ag–(IPr)₂][Ag–(NN)₂]·2H₂O solvate, in which the diradical anion [Ag–(NN)₂]⁻ is bound to two water molecules by hydrogen bonds. These hydrogen bonds stabilize a planar conformation of the [Ag–(NN)₂]⁻ anion, in which both NN fragments lie in the same plane and, according to DFT calculations, are linked by fairly strong antiferromagnetic interaction. DFT calculations also predict the dissociation of the complex with water in toluene solution and a conformational change leading to the appearance of about 90° between NN fragments and a significant decrease in exchange interaction. Full article

We report a rare family of pyridine-coordinated iodobismuthate(III) salts supported by alkyltriphenylphosphonium and tetraphenylphosphonium cations. Reactions of BiI₃ with Ph₃PR⁺I⁻ (R = Me, Et, ⁿPr, ⁿBu, Ph) in neat pyridine, followed by crystallization, yield structurally tunable bismuth-halide-pyridine anions dictated by reagent stoichiometry. Combination of BiI₃ and Ph₃PR⁺I⁻ in 2:1 ratio produced [Ph₃PR]₂[BiI₅Py], 1 (R = Me, Et, ⁿPr, Ph), while combination in 1:1 ratio resulted in three compounds: [Ph₃PR][cis-BiI₄Py₂], 2 (R = ⁿPr, Ph), [Ph₃PR][trans-BiI₄Py₂], 3 (R = Me, Et, Ph), and [Ph₃PR]₂[transoid-Bi₂I₈Py₂], 4 (R = Me, Et, ⁿPr, ⁿBu, Ph). In many cases, the compounds were isolated as Py or Et₂O solvates, and in some cases, multiple degrees of solvation or polymorphism were encountered. Hirshfeld analysis of 1–4 showed the major anion–cation/anion/solvent interactions to be H⋯I, H⋯H, and C⋯H. Diffuse reflectance measurements of representative compounds, all of which were yellow-orange to red-orange, revealed bandgaps in the range of 1.9–2.2 eV, where density-of-states KS-DFT calculations attribute the absorption to metal-centered charge transfer within the anionic unit. NLMO and QTAIM analyses further indicate predominantly ionic Bi(III)–I/pyridine bonding with robust inner-sphere coordination that is insensitive to anion speciation. Full article

2,9-Bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen)-based ligands show great promise in the separation of trivalent lanthanides and actinides. Experimental studies have shown that americium forms stronger complexes with the BTPhen ligands than europium; most theoretical studies have so far failed to reproduce these results. In the current study, three different metal forms (the naked cation, its nitrate or perchlorate salts and tetraaqua solvated salts) were used to study different complexation reactions. It was shown that in the case of naked cations and salts, europium forms the most stable complex with the 2,9-bis(1,2-triazin-3-yl)-1,10-phenanthroline ligand in all of the reactions compared. However, europium is also more strongly interacting (compared to americium) with anions and water molecules in the tetraaquatrinitrato or tetraaquatriperchlorato complexes. That shifts the energies of reactions like Am(NO₃)₃·4H₂O + [Eu(H₂O)₄BTPhen]³⁺ = [Am(H₂O)₄BTPhen]³⁺ + Eu(NO₃)₃·4H₂O in favor of the americium being complexed with BTPhen and europium with anions and water. Therefore, the americium complexes with BTPhen become the more stable form, in an agreement with the experimental studies. Comparison of counterion influence (nitrate vs. perchlorate) indicates that bigger preference for americium over europium complexation corresponds to the nitrate complexes and stems mainly from the fact that in M(NO₃)₃(H₂O)₄ europium is stabilized more than in M(ClO₄)₃(H₂O)₄. Full article

Understanding Li⁺ solvation structure is critical for the rational design of high- and localized high-concentration electrolytes. Here, we present a systematic investigation of tetrahydrofuran (THF)-based electrolytes with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) using Raman spectroscopy and ⁷Li nuclear magnetic resonance to investigate the local solvation structures. By varying the THF:LiTFSI molar ratio, we observed a transition of Li⁺ solvation from solvent-separated ion pairs to contact ion pairs and aggregates, accompanied by increased structural heterogeneity and constrained local dynamics. Raman spectroscopy captures the evolution of Li⁺–anion coordination with increasing salt concentration, while ⁷Li NMR chemical shifts, line widths, and relaxation times provide complementary insight into changes in the electronic environment and symmetry of Li⁺ coordination. Electrolyte structure is further examined by introducing a hydrofluoroether co-solvent into a concentrated (THF)₂–LiTFSI electrolyte. Raman results show that the local Li⁺–TFSI⁻ coordination structure is preserved upon 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) addition, whereas NMR reveals subtle modifications of the ion-rich solvation clusters. These results provide fundamental insight into Li⁺ solvation and electrolyte localization, offering general design principles for advanced electrolyte systems. Full article

Homogeneous Kolbe-Schmitt carboxylation of phenoxides offers a mild and effective alternative to the classical high-temperature solid-phase Kolbe-Schmitt reaction. To develop this into a practical synthetic approach, we investigated several fundamental dependencies, particularly the impact of cations (Na, K, Li, Cs, and Rb), phenoxide concentration, and solvents (DMSO or DMF) on the yield and regioisomeric ratio of hydroxyaromatic carboxylic acids (HACAs). We identified optimal conditions for the effective carboxylation of different phenoxides, including a chiral Ellman’s sulfinamide derived from ortho-vanillin. Both solvents and cations were found to be crucial in the carboxylation of phenoxides. Due to solvation effects, DMSO directs CO₂ attack to the para-position of phenoxide, while DMF, although less selective, generally affords higher HACA yields. The addition of equiv. amounts of mesitolate salt to phenoxide in either DMSO or DMF solution often drives the reaction to completion, resulting in yields of up to 98%. Phenoxides containing several EWG groups, such as halogens or alkyl groups, adjacent to the reaction center show considerably lower reactivity in carboxylation; however, by carefully adjusting parameters, acceptable conversions (>70%) can be achieved. Using the gasometry, we assessed the stability of phenoxide and mesitolate carbonate complexes in DMSO. These experiments revealed distinct stages for the onset of decomposition and carboxylation at atmospheric pressure, indicating a lower energy barrier in the homogeneous process. Further insight into carbonate complex behavior was obtained through DOSY and ¹³C NMR experiments, which support increased molecular association in solution and correlate with enhanced reactivity. Full article

Pyrimethamine (PYR), a drug approved for the treatment of infections caused by protozoan parasites, is a multifunctional API based on 2,4-diaminopyrimidine scaffold. The present study aims toward the development of novel solid forms of PYR, by combining it with three isomeric aminobenzoic acids—2-aminobenzoic acid (2NH₂-BA), 3-aminobenzoic acid (3NH₂-BA), and 4-aminobenzoic acid (4NH₂-BA). Solution crystallization led to the formation of three new solvated salts of PYR (PYR/2NH₂-BA/EtOH/H₂O, PYR/3NH₂-BA/EtOH, and PYR/4NH₂-BA/EtOH/H₂O). The detailed physicochemical properties of the formed compounds were characterized by single-crystal X-ray diffraction (SC-XRD), FTIR, PXRD, thermogravimetry (TG), and differential scanning calorimetry (DSC). Additionally, the pre-crystallization solutions of PYR with 2NH₂-BA, 3NH₂-BA, and 4NH₂-BA were studied by electrospray ionization mass spectrometry technique (ESI-MS), which enabled the observation of peaks corresponding to noncovalently bonded molecules, providing insight into their specific aggregation in a solution/gas phase environment. We identified different non-covalent aggregates, including self-aggregates of aminobenzoic acids and PYR/aminobenzoic acid associates of different stoichiometries. Full article

Metal anodes promise improvements in energy density and cost; however, their performance is determined within the first several nanometers at the interface. This review reports on how polymer-based artificial solid electrolyte interphases (SEIs) are engineered to stabilize Li and aqueous-Zn anodes, and how these designs are now evaluated against operando readouts rather than post-mortem snapshots. We group the related molecular strategies into three classes: (i) side-chain/ionomer chemistry (salt-philic, fluorinated, zwitterionic) to increase cation selectivity and manage local solvation; (ii) dynamic or covalently cross-linked networks to absorb microcracks and maintain coverage during plating/stripping; and (iii) polymer–ceramic hybrids that balance modulus, wetting, and ionic transport characteristics. We then benchmark these choices against metal-specific constraints—high reductive potential and inactive Li accumulation for Li, and pH, water activity, corrosion, and hydrogen evolution reaction (HER) for Zn—showing why a universal preparation method is unlikely. A central element is a system of design parameters and operando metrics that links material parameters to readouts collected under bias, including the nucleation overpotential (η_nuc), interfacial impedance (charge transfer resistance (R_ct)/SEI resistance (R_SEI)), morphology/roughness statistics from liquid-cell or cryogenic electron microscopy (Cryo-EM), stack swelling, and (for Li) inactive-Li inventory. By contrast, planar plating/stripping and HER suppression are primary success metrics for Zn. Finally, we outline parameters affecting these systems, including the use of lean electrolytes, the N/P ratio, high areal capacity/current density, and pouch-cell pressure uniformity, and discuss closed-loop workflows that couple molecular design with multimodal operando diagnostics. In this view, polymer artificial SEIs evolve from curated “recipes” into predictive, transferable interfaces, paving a path from coin-cell to prototype-level Li- and Zn-metal batteries. Full article

Silicon (Si) anodes offer ultrahigh theoretical capacity (~4200 mAh g⁻¹) for next-generation lithium-ion batteries but suffer from severe mechanical degradation due to repetitive volume expansion (>300%). Conventional electrode-centric strategies face scalability limitations, shifting focus to electrolyte engineering as a critical solution. This review synthesizes recent advances in liquid electrolyte design for stabilizing Si anodes, emphasizing three key pillars: (i) Lithium salts that enable anion-derived inorganic-rich solid electrolyte interphase (SEI) layers with high fracture toughness; (ii) Solvent systems including carbonates, ethers, and phosphonates, where fluorination and steric hindrance tailor SEI elasticity; (iii) Functional additives (F/B/Si-containing) that form mechanically compliant interphases and scavenge detrimental species. Innovative architectures—high-concentration electrolytes (HCEs), localized HCEs (LHCEs), and weakly solvating electrolytes—are critically assessed for their ability to decouple ion transport from volume strain. The perspective highlights the imperative of hybrid solid–liquid interfaces to enable commercially viable Si anodes. Full article

The operational failure of lithium-ion batteries under extreme temperatures (−40~60 °C) stems primarily from electrolyte limitations. While prior efforts improved either low-temperature or high-temperature performance independently, holistic electrolyte design with practical validation remains elusive. Herein, we develop an all-climate electrolyte (ACE) through synergistic coordination of solvent, Li salt, and additive, achieving low viscosity (<10 mPa·s at −40 °C) and high ionic conductivity (7.0 mS cm⁻¹ at −40 °C). Raman and NMR spectra reveal MA and EC co-occupying Li⁺ solvation sheath while EMC acts as a diluent, enabling rapid ion transport. Consequently, LiFePO₄ (LFP)|graphite (Gr) cell delivers unprecedented cyclability: zero capacity decay over 500 cycles at 0 °C, stable operation across −40~60 °C, and 94.1% retention after 100 cycles at 45 °C in Ah-level pouch cells. XPS and SEM analysis demonstrate lithium difluorophosphate (LiDFP) and lithium bis(fluorosulfonyl)imide (LiFSI) collaboratively remodel SEI/CEI interphases, enriching them with LiF, Li₃PO₄, and Li₂SO₄. This inorganic-dominant architecture enhances interfacial Li⁺ kinetics and all-climate stability compared to the baseline electrolyte. Our tripartite electrolyte strategy provides a material-agnostic solution for all-climate energy storage. Full article

Lithium–oxygen battery performance is limited by the instability of the electrolytes. Herein, it is shown that highly concentrated DMSO and DMF electrolytes improved resistance to degradation compared to lower electrolyte concentrations. Gravimetric capacities of DMSO-based electrolytes decreased modestly with increasing molar ratio up to 0.4, demonstrating the ability of highly concentrated electrolytes to perform relatively well at the higher concentrations needed to help reduce electrolyte degradation. These cells maintain their cycling lifetimes up to a molar ratio of 0.3 before a dramatic decrease is seen. Previously, DMF had been disregarded as a viable electrolyte in Li–O₂ batteries due to very low gravimetric capacities at low concentrations and a very short cycle life. Here, it is demonstrated for the first time that performance in DMF greatly improves with increasing the Li salt-to-solvent molar ratio, with the capacity peaking at 0.4 for LiTFSI–DMF electrolytes matching the best performance in DMSO at low concentrations. Furthermore, increasing the LiTFSI–DMF concentration greatly improves cycling lifetimes, with cycling lifetimes almost tripling when the LiTFSI–DMF molar ratio increases from 0.1 to 0.25, ~60% larger than that achieved with DMSO. These results suggest that other electrolyte solvents previously thought unusable should be reconsidered for use in Li–O₂ batteries at high concentrations. Full article

Objectives: This study aimed to find salts with similar pharmacological effects designed as cocrystals to improve the aqueous solubility and bioavailability of dihydromyricetin (DMY). Methods: A salt-cocrystal solvate (DMY-CIP·C₂H₆O) of dihydromyricetin and ciprofloxacin hydrochloride (CIP) was successfully prepared via solvent evaporation method, and further characterized using powder X-ray diffraction, thermal analysis, and infrared spectroscopy. The solubility, stability, bioavailability, and in vitro antimicrobial efficacy of the cocrystal were also studied. Results: The cocrystal could increase the solubility of DMY in water and greatly improve the absorption of DMY in vivo (8-fold enhancement in relative bioavailability). In addition, the in vitro antimicrobial efficacy of the cocrystal was comparable to that of CIP, which is a great improvement for DMY. However, due to the formation of cocrystals with salts, the humidity stability of DMY is reduced and it should not be stored in high-humidity environments. Conclusions: These findings demonstrate that cocrystallization with water-soluble salts represents an effective strategy for optimizing the pharmaceutical properties of poorly soluble compounds. Full article

Polymer electrolytes (PEs) provide enhanced safety for high–energy–density lithium metal batteries (LMBs), yet their practical application is hampered by intrinsically low ionic conductivity and insufficient electrochemical stability, primarily stemming from suboptimal Li⁺ solvation environments and transport pathways coupled with slow polymer dynamics. Herein, we demonstrate a molecular design strategy to overcome these limitations by regulating the Li⁺ solvation structure through the synergistic interplay of conventional Lewis acid–base coordination and engineered hydrogen bond (H–bond) networks, achieved by incorporating specific H–bond donor functionalities (N,N′–methylenebis(acrylamide), MBA) into the polymer architecture. Computational modeling confirms that the introduced H–bonds effectively modulate the Li⁺ coordination environment, promote salt dissociation, and create favorable pathways for faster ion transport decoupled from polymer chain motion. Experimentally, the resultant polymer electrolyte (MFE, based on MBA) enables exceptionally stable Li metal cycling in symmetric cells (>4000 h at 0.1 mA cm⁻²), endows LFP|MFE|Li cells with long–term stability, achieving 81.0% capacity retention after 1400 cycles, and confers NCM622|MFE|Li cells with cycling endurance, maintaining 81.0% capacity retention after 800 cycles under a high voltage of 4.3 V at room temperature. This study underscores a potent molecular engineering strategy, leveraging synergistic hydrogen bonding and Lewis acid–base interactions to rationally tailor the Li⁺ solvation structure and unlock efficient ion transport in polymer electrolytes, paving a promising path towards high–performance solid–state lithium metal batteries. Full article