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The fragmentation of ion clusters within the accelerating fields of ionic liquid ion sources (ILISs) is well documented and degrades ILIS performance and lifetime. Some of the most popular ILIS liquids, such as EMI-BF4 (1-Ethyl-3-methylimidazolium tetrafluoroborate) and EMI-Im (1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), emit clusters with lifetimes as low as ∼1 ns. Studies of fragmentation within the accelerating field typically rely on measuring the plume energy distribution averaged over all plume species and comparing those measurements with numerical simulations to estimate ion cluster lifetimes. Here, for the first time, we estimate EMI-BF4 cluster lifetimes by analyzing the energy distributions of individual plume species. We use this novel analysis method to estimate mean lifetimes of positive EMI-BF4 ion clusters from previously published experimental data. We find that the mean lifetime ranges from τ = 3.7 ns to τ = 124 ns for [ EM I + ] [ EMI - B F 4 ] dimers and ranges from τ = 1.5 ns to τ = 23 ns for [ EM I + ] [ EMI - B F 4 ] 2 trimers. Fitting those data to an analytical fragmentation model, we estimate the binding energy and temperature as Δ G S 0 = 0.49 eV and T = 394 K for dimers and Δ G S 0 = 0.40 eV and T = 365 K for trimers. Comparing our results with previous studies supports the conclusion that clusters are emitted with a wide distribution of internal energies, contrary to the common assumption of single internal energy for each species. [ABSTRACT FROM AUTHOR]

A porous electrospray ion source was tested with three ionic liquids in order to investigate the effects of ionic liquid properties on the sizes of ion clusters emitted by purely ionic electrospray sources. Two of the ionic liquids, bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate and 1,6-bis(3-methylimidazolium-1-yl)hexane bis(trifluoromethylsulfonyl)amide, were selected due to them having a dication or dianion, which were termed multiply charged ionic liquids due to them containing anions or cations with more than one charge within them. These were selected in order to investigate ionic clustering within electrospray ion emission and were compared against one of the most common ionic liquids, EMI-BF4. The current–voltage data showed that EMI-BF4 emitted similar levels of current to bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate, even though the latter liquid had significantly lower conductivity and higher viscosity, suggesting an improvement in current speculated to be due to the extra charges contained by the ions. Time-of-flight and retarding potential analysis data are provided, showing all three liquids emitting ions comprising of monomers, dimers, trimers, and quadramers, with some of the 1,6-bis(3-methylimidazolium-1-yl)hexane bis(trifluoromethylsulfonyl)amide data showing heavier species emission. The data also suggested that the multiply charged ionic liquids produced ions that have two anions or cations attached, termed "double ions," with these ions not been previously reported using porous electrospray sources. Furthermore, it was found that the dimers emitted by both of the multiply charged ionic liquids seemed to be more stable than EMI-BF4 dimers, providing insight into ion cluster formation. [ABSTRACT FROM AUTHOR]

The outstanding radiation damage stability of an NiCoCrFePd high entropy alloy (HEA) as compared to conventional alloys poses the question for the mechanism of an ion–matter interaction. The positron annihilation lifetime spectroscopic and TEM (transmission electron microscopic) measurements are implemented to trace different kinds of defects produced by 120 MeV Au+9 ion irradiation and their evolution as a function of ion fluence. The variation of lifetimes and corresponding intensities with the ion fluence indicates the formation of dislocation-type defects at a lower ion fluence and vacancy clusters at a higher ion fluence caused by coalescence or agglomeration of dislocation defects. Formation of different types of defects in turn modulates the strain development inside the crystal. Additionally, the HR-TEM investigation of NiCoCrFePd HEA also exhibits the formation of dislocation and vacancy clusters with the average size of vacancy clusters increases from ∼2.9 ± 0.1 to ∼3.8 ± 0.1 nm with the increases in the ion fluence. Surprisingly, the average defect cluster size in NiCoCrFePd HEA is suppressed compared to NiCoCrFe MEA, thereby showing the enhanced radiation stability on Pd incorporation due to the high defect recombination caused by reduced thermal conductivity and high lattice distortion. Nano-indentation measurement shows that the radiation hardening behavior of the NiCoCrFePd HEA responded slowly owing to its damage suppression property as compared to the NiCoCrFe MEA. Additionally, softening behavior also appeared at an early fluence in NiCoCrFe MEA compared to the NiCoCrFePd HEA signifying its excellent resistance to defect accumulation. [ABSTRACT FROM AUTHOR]

Molecular cluster ions, which are stored in an electromagnetic trap under ultra-high vacuum conditions, undergo blackbody infrared radiative dissociation (BIRD). This process can be simulated with master equation modeling (MEM), predicting temperature-dependent dissociation rate constants, which are very sensitive to the dissociation energy. We have recently introduced a multiple-well approach for master equation modeling, where several low-lying isomers are taken into account. Here, we experimentally measure the BIRD of CO4●–(H2O)1,2 and model the results with a slightly modified multiple-well MEM. In the experiment, we exclusively observe loss of water from CO4●–(H2O), while the BIRD of CO4●–(H2O)2 leads predominantly to loss of carbon dioxide, with water loss occurring to a lesser extent. The MEM of two competing reactions requires empirical scaling factors for infrared intensities and the sum of states of the loose transition states employed in the calculation of unimolecular rate constants so that the simulated branching ratio matches the experiment. The experimentally derived binding energies are ΔH0(CO4●––H2O) = 45 ± 3 kJ/mol, ΔH0(CO4●–(H2O)–H2O) = 41 ± 3 kJ/mol, and ΔH0(CO2–O2●–(H2O)2) = 37 ± 3 kJ/mol. Quantum chemical calculations on the CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVDZ level, corrected for the basis set superposition error, yield binding energies that are 2–5 kJ/mol higher than experiment, within error limits of both experiment and theory. The relative activation energies for the two competing loss channels are as well fully consistent with theory. [ABSTRACT FROM AUTHOR]

The abundance of extraterrestrial methanol makes the reaction between methanol molecules in a molecular cluster a possible key step in the search for mechanisms for the formation of more complex molecules under the conditions of the interstellar medium as well as circumstellar and planetary atmospheres. The reaction leading to the formation of the dimethyl ether ion from a methanol molecule interacting with a protonated methanol ion via the elimination of a water molecule is a basic mechanism for the formation of complex organic molecules. Here, we experimentally examine such reactions in the gas phase, analyzing the production and reactivity of protonated cluster ions formed by the ionization of a supersonic jet of methanol. Focusing especially on the post-collisional relaxation of the protonated methanol dimer and trimer ions after high-energy single collisions, the results indicate a strong size selectivity favoring the occurrence of this reaction only in the dimer ion. To elucidate this behavior, the velocity distribution of the eliminated water molecule was measured using an event-by-event coincidence analysis. These results are interpreted using quantum chemical calculations of the dissociation pathways. It turns out that in the dimer case, two transition states are able to contribute to this intracluster reaction. In the trimer case, methanol evaporation appears as the most energetically favorable relaxation pathway. [ABSTRACT FROM AUTHOR]

Ionic melts, in the form of ionic liquids and molten salts, are important in many technological aspects such as metal production and energy applications. Cryolite melts constitute an important family especially for the industrial production of Al. The present computational study aims to analyse the effect of different cations on the structure and properties of Al (III) fluorocomplexes in cryolite melts. Cation effects are discussed as the ion pair interactions due to alkali metal cations of cryolite compounds M3AlF6 with M= Li, Na, K, Rb, or Cs for various microclusters using ionic interaction model (IM) and DFT calculations. DFT results for different ion complexes are compared with the energy calculations using a pseudoclassical model for isolated clusters. QTAIM and ELF analyses were performed to understand the nature of interactions in detail. A link between open-shell interactions and decreased ionic conductivity is proposed within the series of K, Rb, and Cs. Environmental effects, such as temperature and presence of other ions, are investigated in detail by DFT analysis. [ABSTRACT FROM AUTHOR]

Doping quantum‐confined semiconductor nanocrystals offers an effective way to tailor their unique properties. However, the inherent challenges of nanoscale doping processes, such as the low probability of successful doping, have hindered their practical applications. Nucleation‐controlled doping has emerged as a potential solution, but a comprehensive mechanistic understanding of this process is lacking. Herein, the nucleation‐controlled doping process facilitated by magic‐sized cluster intermediates is elucidated. This approach enables the synthesis of 2D ZnSe quantum nanoribbons with two distinct doping sites. Remarkably, the identity of the dopants plays a critical role in determining the chemical pathways of nucleation‐controlled doping. Substitutional doping of magic‐sized clusters with Mn2+ ions leads to successful substitutional doping of the final 2D nanocrystals. Conversely, Co2+ ions, initially occupying substitutional positions in the magic‐sized cluster intermediates, relocate to alternative sites, such as interstitial sites, in the final nanocrystals. First‐principle calculations of dopant formation energies support these experimental findings, demonstrating the thermodynamic favorability of specific dopant site preferences. Moreover, a consistent tendency is observed in CdSe nanocrystals, suggesting that the proposed doping mechanism is generally applicable to II–VI semiconductors. This study will advance the controlled synthesis of various doped semiconductor nanocrystals using nucleation‐controlled doping processes. [ABSTRACT FROM AUTHOR]

In this work, the features of secondary emission phenomena were investigated under cluster bombardment. The emission of ion‐photons, secondary ions, and electrons associated with the thermal peak regime were experimentally carried out. The experiments were conducted using modernized a static magnetic mass spectrometer. The integral yield of secondary ion and electron emission was measured by bombarding Tb and Tm targets with cluster ions Aum− (m = 1–9) and Bim− (m = 1–7) within the energy range of 1–21 keV for the bombarding ions. Additionally, the integral yield of ion‐photon emission was measured by bombarding a Tm target with cluster ions Bim− (m = 1–5) within the same energy range. The experimental results showed that an increase in the yield of ion‐photon emission, secondary ion, and ion‐electron emission was observed with an increase in the number of atoms bombarded by cluster ions. This can be explained the formation of thermal peaks under dense collision cascades. [ABSTRACT FROM AUTHOR]

Terpenoid cyclases (TCs) account for the synthesis of the most widespread and diverse natural compounds. A sesquiterpene cyclase termed BcABA3 from an abscisic acid-producing fungus Botrytis cinerea that yields (2Z,4E)-α-ionylideneethane but lacks signature feature of canonical TCs represents a distinct type of TCs. Here, we report the crystal structures of BcABA3, a closely related RuABA3 from Rutstroemia sp. and a bacterial SkABA3 from Shimazuella kribbensis. These ABA3 proteins adopt an all-α-helix fold and bind pyrophosphate moiety of farnesyl pyrophosphate by Glu-chelated Mg2+ ion cluster. We conduct mutagenesis experiments to validate the role of the substrate-binding residues. SkABA3 appears to yield compounds that are distinct from (2Z,4E)-α-ionylideneethane. These results not only provide the molecular insight into ABA3 proteins that serve as an important basis to the future investigation of this class of TCs, but also reveal the existence of more uncharacterized terpenoids synthesized via dedicated machineries. BcABA3 catalyzes farnesyl pyrophosphate cyclization but lacks features to be recognized as a terpene cyclase. Here, authors report crystal structures of BcABA3 and homologues to reveal the molecular basis of this distinct type of enzyme. [ABSTRACT FROM AUTHOR]

The 1,1-azoliumdithiocarboxylate cAACMe-CS2 (1a) was prepared and its redox chemistry was evaluated and compared to NHC based dithiocarboxylates IDipp-CS2 (1b) and IMes-CS2 (1c). Radical anions [carbene-CS2]˙− were prepared by metallic reduction as the potassium or magnesium ion complexes [K(18-crown-6)(cAACMe-CS2)] (2a), [K(18-crown-6)(NHC-CS2)] (NHC = IDipp: 2b, IMes: 2c), and [Mg(DippNacNac)(cAACMe-CS2)] (3) and extensively characterized (SC-XRD, EPR, UV/VIS/NIR, DFT). These complexes represent the first examples of isolated radical anions of 1,1-dithiolenes. [ABSTRACT FROM AUTHOR]

We have developed a family of 2,7‐disubstituted 1,8‐naphthalenediol ligands to pre‐organize two metal ions to the distance of two neighboring phosphate diesters of 6–7 Å in the DNA backbone by a rigid backbone. As complexes with divalent ions (CuII and NiII) bind to DNA, interferes DNA synthesis via PCR, and kills human cancer cells more efficiently than human stem cells of the same proliferation rate, we intended to increase the binding affinity by going from divalent to trivalent ions‐especially FeIII. Here, we apply GaIII as redox inactive model for FeIII and obtain for the first time a complex with trivalent ions. However, the structural characterization provides not a dinuclear GaIII complex, but a hexanuclear GaIII complex with a central {GaIII6(μ‐OH)10} core, that is yet unprecedented. [ABSTRACT FROM AUTHOR]

Unsupervised segmentation in biological and non-biological images is only partially resolved. Segmentation either requires arbitrary thresholds or large teaching datasets. Here, we propose a spatial autocorrelation method based on Local Moran's I coefficient to differentiate signal, background, and noise in any type of image. The method, originally described for geoinformatics, does not require a predefined intensity threshold or teaching algorithm for image segmentation and allows quantitative comparison of samples obtained in different conditions. It utilizes relative intensity as well as spatial information of neighboring elements to select spatially contiguous groups of pixels. We demonstrate that Moran's method outperforms threshold-based method in both artificially generated as well as in natural images especially when background noise is substantial. This superior performance can be attributed to the exclusion of false positive pixels resulting from isolated, high intensity pixels in high noise conditions. To test the method's power in real situation, we used high power confocal images of the somatosensory thalamus immunostained for Kv4.2 and Kv4.3 (A-type) voltage-gated potassium channels in mice. Moran's method identified high-intensity Kv4.2 and Kv4.3 ion channel clusters in the thalamic neuropil. Spatial distribution of these clusters displayed strong correlation with large sensory axon terminals of subcortical origin. The unique association of the special presynaptic terminals and a postsynaptic voltage-gated ion channel cluster was confirmed with electron microscopy. These data demonstrate that Moran's method is a rapid, simple image segmentation method optimal for variable and high noise conditions. [ABSTRACT FROM AUTHOR]

The interplay between chirality with magnetism can break both the space and time inversion symmetry and have wide applications in information storage, photodetectors, multiferroics and spintronics. Herein, we report the chiral transition‐metal complex cation‐based lead halide, R‐CDPB and S‐CDPB. In contrast with the traditional chiral metal halides with organic cations, a novel strategy for chirality transfer from the transition‐metal complex cation to the lead halide framework is developed. The chiral complex cations directly participate the band structure and introduce the d‐d transitions and tunable magneto‐chiroptical effects in both the ultraviolet and full visible range into R‐CDPB and S‐CDPB. Most importantly, the coupling between magnetic moment of the complex cation and chiroptical properties is confirmed by the magneto‐chiral dichroism. For the band‐edge transition, the unprecedented modulation of +514 % for S‐CDPB and −474 % for R‐CDPB was achieved at −1.3 Tesla. Our findings demonstrate a novel strategy to combine chirality with magnetic moment, and provide a versatile material platform towards magneto‐chiroptical and chiro‐spintronic applications. [ABSTRACT FROM AUTHOR]

The interplay of ESIPT+TICT mechanisms in 1,8‐naphthalimide–hydroxyquinoline (NQ−OH) molecular rotor were reported for the near‐IR 'turn‐on' emission (λmax 600 nm) and ratiometric (A405nm/A345nm) absorbance‐based detection of Al3+ ions in aqueous medium and live cells which were supported by NMR, IR and CV techniques. The limit of detection (LOD) for Al3+ ions is 100 nM and 14.57 nM. The self‐assembled spherical aggregates of NQ−OH transformed into cuboidal aggregates upon coordination with Al3+ ions supported by microscopic and dynamic light scattering (DLS) techniques. The complex NQ‐OH+Al3+ was further used for the secondary detection of F− ions in aqueous medium via displacement approach with LOD as low as 2.67 nM. A deeper study revealed that the NQ−OH is a solvatochromic dye. Probably, the NQ−OH either in the aggregated state or in the coordination state with Al3+ ions, showed an increase in the emission intensity at 600 nm due to inhibition of the ESIPT process and trigger of the TICT process. We have demonstrated the utility of NQ−OH for the detection of Al3+ ions and NQ‐OH+Al3+ complex for the detection of F− ions in MCF7 live cells. We have also discussed the molecular docking studies of NQ−OH with acetylcholinesterase enzyme. [ABSTRACT FROM AUTHOR]

To characterize the trace-element characteristics of chrysoberyl, we studied twenty-six chrysoberyl samples from various localities by using laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS), photoluminescence (PL), and ultraviolet–visible–near-infrared (UV–Vis–NIR) spectroscopy. Chemical analysis has confirmed the existence of trace elements, including Fe, Ti, Ga, Sn, B, Cr, and V. The phenomenon of ionic isomorphic substitution frequently occurs at lattice sites within chrysoberyl. Notably, the isomorphic substitution of Al3+ in octahedral sites is significant, with the primary substituting elements being Fe, Ti, Cr, V, Ga, and Sn. The PL spectra of chrysoberyl samples exhibit sharp peaks at 678 and 680 nm, which are attributed to Cr3+, even in samples in which the Cr concentration is below the detection limit of LA-ICP-MS. This demonstrates the high-sensitivity feature of PL spectroscopy. The UV–Vis–NIR spectra of chrysoberyl samples consistently exhibit a band at 440 nm, and strong double narrow bands near 367 nm and 375 nm are observed. These spectral features are associated with Fe3+ chromophores—specifically, Fe3+-Fe3+ pairs or clusters and Fe3+ ions, respectively. By combining LA–ICP–MS analysis and PL mapping on a sample exhibiting color zoning, it has been found that the darker sections contain a higher concentration of Cr compared to the lighter sections, while the concentrations of other elements remain largely consistent. In other words, subtle variations in Cr concentration may be the underlying cause of color zoning in chrysoberyl. [ABSTRACT FROM AUTHOR]

Many bacteria swim in liquids and move over solid surfaces by rotating flagella. The bacterial flagellum is a supramolecular protein complex that is composed of about 30 different flagellar proteins ranging from a few to tens of thousands. Despite structural and functional diversities of the flagella among motile bacteria, the flagellum commonly consists of a membrane-embedded rotary motor fueled by an ion motive force across the cytoplasmic membrane, a universal joint, and a helical propeller that extends several micrometers beyond the cell surface. The flagellar motor consists of a rotor and several stator units, each of which acts as a transmembrane ion channel complex that converts the ion flux through the channel into the mechanical work required for force generation. The rotor ring complex is equipped with a reversible gear that is regulated by chemotactic signal transduction pathways. As a result, bacteria can move to more desirable locations in response to environmental changes. Recent high-resolution structural analyses of flagella using cryo-electron microscopy have provided deep insights into the assembly, rotation, and directional switching mechanisms of the flagellar motor complex. In this review article, we describe the current understanding of the structure and dynamics of the bacterial flagellum. [ABSTRACT FROM AUTHOR]

The salt fractions of milk consist of cations (e.g., Ca, Mg, and Na) and anions (e.g., phosphate, citrate, and chloride). These salts are present as free ions or in complexes with other ions or proteins, primarily the caseins. Furthermore, significant levels of Ca and phosphate are also found in insoluble form, inside the casein micelles. The distribution of salts between this micellar phase and the soluble phase is important for the stability and properties of milk and dairy products. Various processes, such as (ultra-)centrifugation, (ultra-)filtration, dialysis, and selective precipitation have been used to separate the micellar and soluble phases in milk and dairy products to allow for studying the salts' distribution between these phases. These different methods can lead to different levels of soluble salts because the salts in the supernatant from centrifugation, the permeate from ultrafiltration, and the diffusate from dialysis can differ notably. Hence, understanding which components are fractionated with these techniques and how this affects the levels of the soluble salts determined is critical for milk and dairy products. Applying the aforementioned methods to cheese products is further challenging because these methods are primarily developed for fractionating the soluble and micellar phases of milk. Instead, methods that analyze salts in water-soluble extracts, or soluble phases expressed from cheese by pressing or centrifugation are typically used. This review focuses on the significance of salt distribution and variations in salt fractions obtained using different methodologies for both milk and cheese. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of sodium hexametaphosphate (SHMP), a complexing reagent for Ca and Mg ions, on iron ore reverse cationic flotation. Quartz and hematite samples contaminated with both Ca and Mg were subjected to microflotation assays at pH 10.5 with starch and etheramine, which showed that SHMP did not provide selectivity in the separation of these minerals. Zeta potential measurements, Fourier transform infrared spectroscopy of quartz and hematite without and with the studied reagents (starch, amine, SHMP, CaCl2/MgCl2) and published studies in the literature indicated that although the HMP anions removed the Ca and Mg ions from both minerals, it also formed complexes with the Fe3+ ions on the hematite surface, which prevented subsequent adsorption of starch and consequently decreased the selectivity for reverse flotation of iron ore. [ABSTRACT FROM AUTHOR]

Aim: The present study aimed to synthesize and characterize magnetic nanoparticle incorporated nanohydroxyapatite (MNHAP), calcium and phosphate ion clusters (CPICs), and their combination with MNHAP. Materials and Methods: Nanohydroxyapatite (NHAP), magnetite (Fe3O4), and magnetic nanoparticle-incorporated nanohydroxyapatite (MNHAP) were synthesized using wet precipitation method, co-precipitation method, and ultrasonic-assisted mechanical stirring methods, respectively. CPIC was synthesized by centrifugation method. Their characterizations were analyzed through X-ray diffraction (XRD) crystallography, Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and high-resolution transmission electron microscopy. The biocompatibility of MNHAP was assessed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: XRD substantiated the presence of diffraction peaks, indicating crystallinity in all synthesized samples. Functional groups in NHAP and MNHAP were confirmed through FTIR analysis. VSM analysis demonstrated superparamagnetic behavior in both MNHAP and Fe3O4. Transmission electron microscope images unveiled the needle-like crystals for NHAP, rod-shaped crystals for MNHAP, and polyhedral shapes for CPIC combined with MNHAP (CPIC + MNHAP). MNHAP exhibited biocompatibility up to 200 µg. Conclusion: Based on the findings of this study, MNHAP and CPIC + MNHAP may be suitable for the repair of initial caries lesions. [ABSTRACT FROM AUTHOR]

ABSTRACT A salamo‐type bis‐oxime ligand H2L was synthesized, which reacted with Ni (NO3)2·6H2O in different reaction solvents to synthesize two novel heptanuclear Ni (II) complexes: [Ni7(L)3(μ3‐OH)8(EtOH)6]·2CH2Cl2 (1) and [Ni7(L)3(μ3‐OMe)2(μ3‐OH)6(MeOH)6]·CH2Cl2 (2). X‐ray crystal diffraction results showed that each Ni (II) ion exhibits a distorted octahedral geometry. Its uniqueness lies in the fact that the Ni (II) ion in Complex 1 not only coordinates with ligand units but also coordinates with ethanol solvent molecules and water molecules participating in bridging. Complex 2 is composed of water molecules and methanol molecules connected together. Interestingly, the coordination mode is different due to the different reaction solvents. The energy gap changes of the ligand, and its complexes were then explored by DFT calculations. In addition, the influence of the weak interaction force was confirmed through the in‐depth study of electrostatic potential, IRI, freedom analysis, and Hirshfeld surfaces analyses, which is important for explaining the formation of reaction sites and supramolecular structures. UV‐visible spectrometric titration tests showed that the binding ratios of the ligand to Ni (II) ions are all 3:7, which is consistent with the crystal structure. Finally, fluorescence characterization studies showed that both complexes exhibited reduced fluorescence compared to H2L. [ABSTRACT FROM AUTHOR]

Nickel is an important element utilized in various industrial/metallurgical processes, such as surgical and dental prostheses, Ni-Cd batteries, paint pigments, electroplating, ceramics, computer magnetic tapes, catalysis, and alloy manufacturing. However, its extensive use and associated waste production have led to increased nickel pollution in soils and water bodies, which adversely affects human health, animals and plants. This issue has prompted researchers to develop various optical probes, hereafter luminescent/colorimetric sensors, for the facile, sensitive and selective detection of nickel, particularly in biological and environmental contexts. In recent years, numerous functionalized chemosensors have been reported for imaging Ni2+, both in vivo and in vitro. In this context, metal-based receptors offer clear advantages over conventional organic sensors (viz., organic ligands, polymers, and membranes) in terms of cost, durability, stability, water solubility, recyclability, chemical flexibility and scope. This review highlights recent advancements in the design and fabrication of hybrid receptors (i.e., metal complexes and MOFs) for the specific detection of Ni2+ ions in complex environmental and biological mixtures. [ABSTRACT FROM AUTHOR]

Direct electrochemical seawater splitting is a renewable, scalable, and potentially economic approach for green hydrogen production in environments where ultra‐pure water is not readily available. However, issues related to low durability caused by complex ions in seawater pose great challenges for its industrialization. In this review, a mechanistic analysis of durability issues of electrolytic seawater splitting is discussed. We critically analyze the development of seawater electrolysis and identify the durability challenges at both the anode and cathode. Particular emphasis is given to elucidating rational strategies for designing electrocatalysts/electrodes/interfaces with long lifetimes in realistic seawater including inducing passivating anion layers, preferential OH−adsorption, employing anti‐corrosion materials, fabricating protective layers, immobilizing Cl− on the surface of electrocatalysts, tailoring Cl− adsorption sites, inhibition of OH− binding to Mg2+ and Ca2+, inhibition of Mg and Ca hydroxide precipitation adherence, and co‐electrosynthesis of nano‐sized Mg hydroxides. Synthesis methods of electrocatalysts/electrodes and innovations in electrolyzer are also discussed. Furthermore, the prospects for developing seawater splitting technologies for clean hydrogen generation are summarized. We found that researchers have rethought the role of Cl− ions, as well as more attention to cathodic reaction and electrolyzers, which is conducive to accelerate the commercialization of seawater electrolysis. [ABSTRACT FROM AUTHOR]

This article considers the problem of the influence of the solvation shell on the ultraviolet-visible absorption spectra of π-conjugated complexes of different metal ions with dicarbonyl ligands. Based on a wide spectral dataset that has been previously collected, we report the direct correlation between the wavelength of maximum absorbance of the complexes and the coordination properties of the metal ions. Chalcogen-bearing diketones (2-furoyl-trifluoroacetone, 2-thenoyl-trifluoroacetone, 2-selenophen-trifluoroacetone, and 2-tellurophen-trifluoroacetone) demonstrate a significant redshift (17–29 nm) of the absorption bands for complexes of metal ions with various solvation shells. The spectral shift increases with an increasing number of water molecules in the hydration sphere. Detailed measurements show the red shift even for different lanthanide complexes. The discovered relationships allow us to compare at a qualitative level the structure of the solvation shell of π-conjugated dicarbonyl complexes. [ABSTRACT FROM AUTHOR]

Benzoate substituted with a cationic quaternary ammonium group at the para‐position, [4‐(CH3)3N(C6H4)CO2], forms mononuclear alkali metal ion complexes, [4‐(CH3)3N(C6H4)CO2M]+ (M=Li, Na, K, Rb and Cs), which are observed by electrospray‐ionisation mass spectrometry. When mass selected and subjected to collision‐induced dissociation each of these complexes undergoes decarboxylation to produce the mononuclear arylalkali complex cations, [4‐(CH3)3N(C6H4)M]+, which subsequently react with water via hydrolysis to yield the quaternary ammonium cation, (CH3)3NC6H5+. The unexpected product ions, [M((CH3)2NC6H5)]+, [M(CH3OH)]+, and M+, which are associated with the hydrolysis pathway, suggest an unusual reaction occurring within the exit channel ion‐molecule complex, [(CH3)3NC6H5+MOH]+. DFT calculations were used to examine the: decarboxylation reaction of [4‐(CH3)3N(C6H4)CO2M]+, which readily proceeds via a four‐centred transition state; the hydrolysis and SN2 reactions accounting for formation of products in the exit channel, which are connected via a roaming mechanism in which the metal hydroxide moiety migrates from the para‐hydrogen of (CH3)3NC6H5+ to one of the methyl groups. [ABSTRACT FROM AUTHOR]

Incorporating appropriate molecules into ordered porous framework materials plays a pivotal role in modulating their physicochemical properties and dynamic behaviors. Such frameworked materials are also applicable for the preparation of solid‐state electrolyte (SSE) with altered electrochemical performance. In this work, MOF (Metal‐Organic Framework)‐based frameworked electrolytes (FEs) are prepared by the introduction of conductive ion‐molecule complexes and have investigated the electrochemical behaviors. The angstrom‐level pores in the framework enable efficient interactions with the complexes and participation in ion transportation by altering the coordinating environments of Li+ ions. As a result, the activated MOF‐based SSE exhibits an impressive ionic conductivity of 4.0×10−4 S cm−1 at room temperature (RT), along with a notably reduced activation energy of 0.12 eV at 350 K. The MOF‐based FE has been applied to Li /FE /LiFePO4 batteries, which exhibit excellent long‐cycling performance with virtually no capacity loss over 1000 cycles at the current density of 2 C at RT. The novel Li+ transport mechanisms where ion‐molecules would actively participate in the interactions between the framework and Li+ ions, not only present a new strategy for enhancing the ion transport kinetics, but also deliver outstanding electrochemical performance promising for next‐generation batteries. [ABSTRACT FROM AUTHOR]

Diabetic wound healing presents a persistent clinical challenge, often characterized by prolonged healing times, and can be particularly difficult to achieve in a hyperglycemic environment. In this study, a multi‐functional silver‐enzyme nanogels assembly (Ag‐nGHC) is designed by focusing on the complex diabetic wound environment. Glucose oxidase (GOX), horseradish peroxidase (HRP), and catalase (CAT) are modified within polymeric nanogel layers and assembled into a large enzyme cluster with silver ions. The close attachment of three enzymes ensures fast and continuous consumption of a high level of glucose, generation of oxygen, and hydroxyl radicals (•OH) around the wound site. Meanwhile, the silver ions within the Ag‐nGHC assembly act as an effective agent to kill bacteria. This cascade enzyme system significantly improves the microenvironment of the wound site by reducing bacterium infection and alleviating hypoxia as well as hyperglycemia. Sequentially, the improved environment facilitates the later processes including anti‐inflammatory, re‐epithelialization, and angiogenesis, evidenced by enhancing polarization toward M2 macrophages and increasing CD31 signals in this study. Overall, the Ag‐nGHC materials are proven to achieve multifunctional properties toward complicated diabetic wound healing processes (attributes such as adaptability, hypoxia‐alleviated, anti‐hyperglycemic, antimicrobial, anti‐inflammatory, and angiogenic) and showed great potential for the treatment of chronic diabetic wound. [ABSTRACT FROM AUTHOR]

A fast, simple, accurate, precise, and cheap fluorimetric protocol has been proposed for analysis of a phosphodiesterase-IV inhibitor, namely drotaverine hydrochloride. Fluorimetric protocol is based on estimating the decrease in the eosin Y fluorescence intensity by quantitative addition of drotaverine at pH 3.1 (acetate buffer). An ion pair complex is formed, which leads to quenching in the fluorescence intensity of the dye without need of prior extraction at 534 nm (λex. 339 nm). Different reaction perimeters which influence the production of complex (ion pair between drotaverine and eosin) were deeply investigated and optimized. The developed fluorimetric protocol is capable for quantitative estimation of drotaverine in linear range of 0.4 to 2.5 µg mL−1. After method validation in respect to ICH guidelines, it was applied to determine drotaverine in its commercial preparation. By comparing with other reported method, the developed and validated fluorimetric protocol is capable for estimation of drotaverine in commercial preparation with good accuracy and excellent precision. [ABSTRACT FROM AUTHOR]

To elucidate the influence of gas cluster-induced impacts on the deep structure of disturbances in tungstate optical materials, experimental studies were carried out. The precision-polished surface of a KGd(WO4)2 (KGW) single crystal was processed by an argon cluster ion beam with the average cluster size of 1000 atom/cluster at the energy of 10 keV, which ensures minimal damage and high processing efficiency. By using high-resolution TEM and EDX techniques of the transversely cut lamellae, the alterations in both the structure and chemical composition at varying depths were explore. In a 15 nm thick subsurface layer of the initial specimen, a nonuniform depth distribution was found for the constituent atoms of KGW. The results showed that, after the cluster bombardment, the initial amorphous layer thickness resulting from precision chemical–mechanical polishing was decreased from 50 to 23 nm. The distribution nonuniformity of constituent KGW atoms decreases in the upper subsurface layer, while it increases at greater depths. [ABSTRACT FROM AUTHOR]

The tetrazwitterionic, tetracarboxylate (benzene-1,2,4,5-tetrayl)tetrakis(3-(1-carboxylatomethylpyridinium)) (L) has been synthesized and used as a ligand in mixed-ligand complexes of the uranyl cation involving anionic carboxylates. {[(UO2)2(tdc)2(L)]·2H2O} n (1), where tdc2– is 2,5-thiophenedicarboxylate, crystallizes as a monoperiodic, ladder-like coordination polymer in which two UO2(tdc) rows are bridged by L ligands with monodentate carboxylate groups. {[(UO2)2(OH)4(L)]·2H2O} n (2) is a diperiodic polymer in which the dinuclear (UO2)2(OH)22+ units are the nodes of a square lattice (sql) network and L being bound by its four monodentate carboxylate groups. The positional isomer (benzene-1,2,4,5-tetrayl)tetrakis(4-(1-carboxylatomethylpyridinium)) (L′) undergoes decarboxylation during synthesis under solvo-hydrothermal conditions, giving tetracationic (benzene-1,2,4,5-tetrayl)tetra{4-(N -methylpyridinium)} (btp4+) included as a counterion in [btp][(UO2)4(O)2(pht)4]·1.5H2O (3), where pht2– is phthalate. The discrete, tetranuclear complexes in 3 are of the usual form with two μ3-oxo bridges and rows of alternating anions and cations linked through π–π interactions arranged into layers. Although the uses of uranium in the nuclear industry are well known, the element has a remarkably varied chemistry, exploited, for example, in photooxidation catalysis for the destruction of environmental pollutants. To this end, it is desirable to have compounds in the highest oxidation state of uranium, +VI, 'uranyl' complexes, that are luminescent and insoluble but porous, ideally containing cavities that generate selectivity with regard to absorbed species. Coordination polymers continue to be developed as materials that may provide such properties. (Image credit: Pierre Thuéry.) [ABSTRACT FROM AUTHOR]

The application of hydrogen flooding was recently shown to be a simple and effective approach for improved layer differentiation and interface determination during secondary ion mass spectrometry (SIMS) depth profiling of thin films, as well as an approach with potential in the field of quantitative SIMS analyses. To study the effects of hydrogen further, flooding of H2 molecules was compared to reactions with atomic H on samples of pure metals and their alloys. H2 was introduced into the analytical chamber via a capillary, which was heated to approximately 2200 K to achieve dissociation. Dissociation of H2 up to 30% resulted in a significant increase in the intensity of the metal hydride cluster secondary ions originating from the metallic samples. Comparison of the time scales of possible processes provided insight into the mechanism of hydride cluster secondary ion formation. Cluster ions presumably form during the recombination of the atoms and molecules from the sample and atoms and molecules adsorbed from the gas. This process occurs on the surface or just above it during the sputtering process. These findings coincide with those of previous mechanistic and computational studies. [ABSTRACT FROM AUTHOR]

The Arctic river basins, among the most sensitive regions to climate warming, are experiencing rapid temperature rise and permafrost thawing that profoundly affect their hydrological and hydrochemical systems. However, our understanding of chemical export from Arctic basins to oceans remains limited due to scarce data, particularly in permafrost-dominated regions. This study examines the spatiotemporal variations and seasonal dynamics of major ions (Na+, K+, Mg2+, Ca2+, Cl−, SO42−) and dissolved organic carbon (DOC) concentrations across three river basins with varying permafrost extents: the Severnaya Dvina (2006–2008, 2012–2014), the Pechora (2016–2019) and the Taz Rivers (2016–2020). All the data were sourced from published Chemical Geological researches and were taken from Mendeley and PANGAEA datasets. Our results showed that DOC concentrations ranged from 1.75 to 26.40 mg/L, with the Severnaya Dvina River exhibiting the highest levels of DOC concentrations, alongside significantly elevated ion concentrations compared to the other two basins. A positive correlation was observed between DOC concentrations and river discharge, with peaks during the spring flood and summer baseflow due to leaching processes. The Severnaya Dvina and Pechora Rivers exhibited the highest DOC values during the spring flood, reaching 26.40 mg/L and 8.07 mg/L, respectively. In contrast, the Taz River had the highest runoff during the spring flood season, but the DOC concentration reached its highest value of 11.69 mg/L in the summer. Specifically, a 1% increase in river discharge corresponded to a 1.25% rise in DOC concentrations in the Severnaya Dvina River and a 1.04% increase in the Pechora River, while there was no significant correlation between runoff and DOC concentrations in the Taz River. Major ion concentrations demonstrated a negative correlation with river discharge, remaining relatively high during winter low-flow period. A robust power-law relationship between river discharge and concentration of DOC and major ions was observed, with distinct variations across the three river basins depending on permafrost extent. The Pechora and Taz Rivers, characterized by extensive permafrost, exhibited increasing trends in river discharge and DOC concentrations, accompanied by decreasing major ion concentrations, whereas the non-permafrost-dominated Severnaya Dvina River basin showed the opposite pattern. The Taz River, with the most extensive permafrost, also displayed a delayed DOC peak and more complex seasonal ion concentration patterns. These findings highlight the importance of varying permafrost extents and their implications for water quality and environmental protection in these vulnerable regions. [ABSTRACT FROM AUTHOR]

In response to the global issue of water scarcity exacerbated by climate change, this study investigates the physicochemical properties of water resources within the Algerian hydrographic basin. Despite efforts to develop groundwater sources for drinking water, contamination risks from nearby agricultural and industrial activities remain significant. To address this, the study focuses on characterizing these water sources, particularly noting elevated levels of nitrates and manganese ions beyond acceptable limits. Despite the negative correlation between manganese and nitrate ions, we have modeled complexes containing both and compared them with others to assess their chemical and biological activities. This integrated approach allows us to understand complex ion interactions and propose innovative solutions for managing water resources more effectively. Through our work, we aim to contribute to the development of sustainable water management strategies, bridging the gap between theoretical modeling based on Density Functional Theory and practical applications. By combining empirical data with theoretical insights, we aspire to offer comprehensive solutions for mitigating water contamination and ensuring access to clean drinking water for communities in the Algerian hydrographic basin. [ABSTRACT FROM AUTHOR]

Mercury, a toxic heavy metal produced through both natural and anthropogenic processes, is found in all of Earth's major systems. Mercury's bioaccumulation characteristics in the human body have a significant impact on the liver, kidneys, brain, and muscles. In order to detect Hg2+ ions, a highly sensitive and specific fluorescent biosensor has been developed using a novel, modified seven amino acid peptide, FY7. The tyrosine ring in the FY7 peptide sequence forms a 2:1 complex with Hg2+ ions that are present in the water-based sample. As a result, the peptide's fluorescence emission decreases with higher concentrations of Hg2+. The FY7 peptide's performance was tested in the presence of Hg2+ ions and other metal ions, revealing its sensitivity and stability despite high concentrations. Conformational changes to the FY7 structure were confirmed by FTIR studies. Simultaneously, we designed a miniaturized setup to support an in-house-developed micro-volume capillary container for volume fluorometry measurements. We compared and verified the results from the micro-volume system with those from the commercial setup. The micro-volume capillary system accommodated only 2.9 µL of sample volume, allowing for rapid, sensitive, and selective detection of toxic mercury (II) ions as low as 0.02 µM. [ABSTRACT FROM AUTHOR]

The rhombohedral phase of gallium oxide (α-Ga2O3) is of interest because of its highest bandgap among the rest of the Ga2O3 polymorphs, making it particularly attractive in applications. However, even though the ion beam processing is routinely used in device technology, the understanding of radiation phenomena in α-Ga2O3 is not mature. Here, we study non-linear effects for radiation disorder formation in α-Ga2O3 by varying both the defect generation rate and the density of collision cascades, enabled by comparing monoatomic and cluster ion implants, also applying systematic variations of ion fluxes. In particular, we show that the collision cascade density governs the surface amorphization rates, also affected by the ion flux variations. These trends are explained in terms of the non-linear in-cascade and inter-cascade defect interactions occurring during ballistic and dynamic defect annealing stages. As such, these data reveal new physics of the radiation phenomena in α-Ga2O3 and may be applicable for more predictive ion beam processing of α-Ga2O3-based devices. [ABSTRACT FROM AUTHOR]

2′-(hexyloxy)-[1,1′-biphenyl]-2-yl 5-(dimethylamino)naphthalene-1-sulfonate (KC1) was synthesized by using biphenol and dansyl chloride as starting materials. The KC1 was characterized via single X-ray diffraction, FTIR, HRMS and 1H and 13C-NMR. The KC1 indicates triclinic as P1 in the space group type. From the KC1, the biphenolic backbone structure is twisted at an angle of 54.48° due to connecting the dansyl unit and hexyl moiety. Upon the addition of the Fe3+ ion to the KC1 solution, the fluorescence emission at 585 nm of KC1 was quenched due to complexation between KC1 and the Fe3+ ion. The complexation ratio of KC1 and Fe3+ was determined to be a 1:1 formation via Job's analysis. The Stern–Volmer constant (Ksv) calculated was 21,203 M−1 for the KC1 and the Fe3+ ion complex. [ABSTRACT FROM AUTHOR]

Intermolecular Coulombic decay or electron transfer-mediated decay are the autoionization processes through which a molecule can relax. This relaxation is only possible if the inner valence's ionization potential (IP) exceeds the system's double ionization potential (DIP). To study the effects of charge and solvation shell, we have calculated the IP, DIP values, and lifetime of Na-2s and Mg-2s temporary bound states in various optimized structures of Na+-(H2O)n and Mg2+-(H2O)n (n = 1–5) micro-solvated clusters, where n water molecules are distributed in a way that some are directly bound to the metal ion and the rest to the water molecules. The first and second solvation shells are the names for the former and the latter water-binding positions, respectively. For a given n, the lifetime of decaying states is longer when water molecules are in the second solvation shell. We found that the Mg-2p state can decay for all n values in Mg2+-(H2O)n clusters, whereas the Na-2p state's decay is possible for n ≥ 2 in Na+-(H2O)n clusters. Our findings highlight the influence of metal ions' charge, different solvation shell structures, and the number of water molecules on the decay rate. These systems are relevant to the human body, which makes this study significant. [ABSTRACT FROM AUTHOR]

• Water probe can be applied to a wide range of pH for acidic and alkaline particles. • A standard spectral library was constructed that identifies ions in complex systems. • Successfully pH measurement for multicomponent particles. • Correlations between volatile acid evaporation and pH were established. The acidity of atmospheric aerosols influences fundamental physicochemical processes that affect climate and human health. We recently developed a novel and facile water-probe-based method for directly measuring of the pH for micrometer-size droplets, providing a promising technique to better understand aerosol acidity in the atmosphere. The complex chemical composition of fine particles in the ambient air, however, poses certain challenges to using a water-probe for pH measurement, including interference from interactions between compositions and the influence of similar compositions on water structure. To explore the universality of our method, it was employed to measure the pH of ammonium, nitrate, carbonate, sulfate, and chloride particles. The pH of particles covering a broad range (0–14) were accurately determined, thereby demonstrating that our method can be generally applied, even to alkaline particles. Furthermore, a standard spectral library was developed by integrating the standard spectra of common hydrated ions extracted through the water-probe. The library can be employed to identify particle composition and overcome the spectral overlap problem resulting from similar effects. Using the spectral library, all ions were identified and their concentrations were determined, in turn allowing successful pH measurement of multicomponent (ammonium-sulfate-nitrate-chloride) particles. Insights into the synergistic effect of Cl–, NO 3 –, and NH 4 + depletion obtained with our approach revealed the interplay between pH and volatile partitioning. Given the ubiquity of component partitioning and pH variation in particles, the water probe may provide a new perspective on the underlying mechanisms of aerosol aging and aerosol–cloud interaction. [Display omitted] [ABSTRACT FROM AUTHOR]

Mg1/3A11/3A21/3Ta2O6 ceramics (where A1 and A2 represent Co, Ni, or Zn) were prepared using the solid‐phase reaction route. The results of X‐ray diffraction and Raman tests showed that (Co1/2Ni1/2)2+, (Co1/ 2Zn1/2)2+, and (Ni1/2Zn1/2)2+ ions replaced Mg2+ ions in the lattice of MgTa2O6, resulting in the formation of a pure tri‐rutile structure. All three complex ions could significantly reduce the sintering temperature of the ceramics (by 150°C–200°C) and could broaden the sintering window. The large deviation (48.8%–69.2%) between the porosity corrected relative permittivity εr‐corr. and the theoretical relative permittivity εr‐theo. might be due to the overestimation of the ionic polarizability of Ta5+ by Shannon. (Co1/2Ni1/2)2+ has the most significant effect of increasing the bond energy of ceramic A–O bonds, reducing the τf value from 51 to 36 ppm/°C. In addition, the mechanisms affecting their dielectric properties are discussed based on bond ionicity (fi), full width at half maximum (FWHM) of Raman peak, and bond energy (E). Mg1/3Co1/3Ni1/3Ta2O6 ceramic sintered at 1350°C have the most excellent microwave dielectric properties: εr = 26.8, Q × f = 86,000 GHz, and τf = 36 ppm/°C. [ABSTRACT FROM AUTHOR]

Ultrafast transient vibrational action spectra of cryogenically cooled Re(CO)3(CH3CN)3+ ions are presented. Nonlinear spectra were collected in the time domain by monitoring the photodissociation of a weakly bound N2 messenger tag as a function of delay times and phases between a set of three infrared pulses. Frequency-resolved spectra in the carbonyl stretch region show relatively strong bleaching signals that oscillate at the difference frequency between the two observed vibrational features as a function of the pump–probe waiting time. This observation is consistent with the presence of nonlinear pathways resulting from underlying cross-peak signals between the coupled symmetric–asymmetric C≡O stretch pair. The successful demonstration of frequency-resolved ultrafast transient vibrational action spectroscopy of dilute molecular ion ensembles provides an exciting, new framework for the study of molecular dynamics in isolated, complex molecular ion systems. [ABSTRACT FROM AUTHOR]

We report a joint negative ion photoelectron spectroscopy (NIPES) and quantum chemical computational study on glycine-chloride/bromide complexes (denoted Gly·X−, X = Cl/Br) in close comparison to the previously studied Gly·I− cluster ion. Combining experimental NIPE spectra and theoretical calculations, various Gly·X− complexes were found to adopt the same types of low-lying isomers, albeit with different relative energies. Despite more congested spectral profiles for Gly·Cl− and Gly·Br−, spectral assignments were accomplished with the guidance of the knowledge learned from Gly·I−, where a larger spin–orbit splitting of iodine afforded well-resolved, recognizable spectral peaks. Three canonical plus one zwitterionic isomer for Gly·Cl− and four canonical conformers for Gly·Br− were experimentally identified and characterized in contrast to the five canonical ones observed for Gly·I− under similar experimental conditions. Taken together, this study investigates both genericity and variations in binding patterns for the complexes composed of glycine and various halides, demonstrating that iodide-tagging is an effective spectroscopic means to unravel diverse ion-molecule binding motifs for cluster anions with congested spectral bands by substituting the respective ion with iodide. [ABSTRACT FROM AUTHOR]

The structures of magnesium chloride dimer-water clusters, (MgCl2)2(H2O)n−/0, were investigated with size-selected anion photoelectron spectroscopy and theoretical calculations to understand the dissolution of magnesium chloride in water. The most stable structures were confirmed by comparing vertical detachment energies (VDEs) with the experimental measurements. A dramatic drop of VDE at n = 3 has been observed in the experiment, which is in accordance with the structural change of (MgCl2)2(H2O)n−. Compared to the neutral clusters, the excess electron induces two significant phenomena in (MgCl2)2(H2O)n−. First, the planar D2h geometry can be converted into a C3v structure at n = 0, making the Mg–Cl bonds easier to be broken by water molecules. More importantly, a negative charge-transfer-to-solvent process occurs after adding three water molecules (i.e., at n = 3), which leads to an obvious deviation in the evolution of the clusters. Such electron transfer behavior was noticed at n = 1 in monomer MgCl2(H2O)n−, indicating that the dimerization between two MgCl2 molecules can make the cluster more capable of binding electron. In neutral (MgCl2)2(H2O)n, this dimerization provides more sites for the added water molecules, which can stabilize the entire cluster and maintain its initial structure. Specifically, filling the coordination number to be 6 for Mg atoms can be seen as a link between structural preferences in the dissolution of the monomers, dimers, and extended bulk-state of MgCl2. This work represents an important step forward into fully understanding the solvation of MgCl2 crystals and other multivalent salt oligomers. [ABSTRACT FROM AUTHOR]

In this work, we present coordinated molecular dynamics, ion cluster acceleration, and retarding potential analysis simulations to determine cluster fragmentation behavior in a realistic emitter geometry for electrosprays operating in the pure ionic regime. Molecular dynamics simulations are used to determine the fragmentation rates of ionic liquid clusters as a function of internal energy, electric field strength, and cluster size. A simplified model of electrospray cluster acceleration is developed from previous electrohydrodynamic emission models and used to simulate retarding potential analysis curves. Fragmentation rates and beam composition are inferred for experimental data based on the molecular dynamics and cluster acceleration simulations. We find that for these experimental data, temperatures of EMI-BF 4 dimers likely range between 590 and 687 K while trimer temperatures are larger between 989 and 1092 K. The percentage of monomers, dimers, and trimers in the beam is approximately 45%, 30%–43%, and 13%–25%, respectively. Both ionic liquid cluster temperatures and beam composition agree with previous analysis of this experimental work, supporting the use of coordinated molecular dynamics and retarding potential analysis as a method of inferring electrospray beam parameters. Insights gained from this simulation process are discussed in the context of currently unexplained electrospray emitter behavior and experimental results including the presence of tetramers and trimers in the beam and fragmentation rates in high electric field regions. [ABSTRACT FROM AUTHOR]

Intracellular protein delivery has the potential to revolutionize cell-biological research and medicinal therapy, with broad applications in bioimaging, disease treatment, and genome editing. Herein, we demonstrate successful delivery of a functional protein, cytochrome c (CYC), by using a boron cluster anion as molecular carrier of the superchaotropic anion type (B12Br11OPr2-). CYC was delivered into lipid bilayer vesicles as well as living cells, with a cellular uptake ratio approaching 90%. Mechanistic studies showed that CYC was internalized into cells through a permeation pathway directly into the cytoplasm, bypassing endosomal entrapment. Upon carrier-assisted internalization, CYC retained its bioactivity, as reflected by an induced cell apoptosis rate of 25% at low dose (1 µM). This study furbishes a direct protein delivery method by a molecular carrier with high efficiency, confirming the potential of inorganic cluster ions as protein transport vehicles with an extensive range of future cell-biological or biomedical applications. [ABSTRACT FROM AUTHOR]

Diatomic catalysts (DACs), as a frontier of research on atomically dispersed catalysts, have drawn great attention, especially in electrocatalysis. However, most of the current synthetic strategies for DACs suffer from poor efficiency and high cost. In this work, a novel noncovalent assembly strategy is reported for the efficient synthesis of DACs. By the aid of two kinds of noncovalent intermolecular force, the π–π stacking and Coulomb forces, a pair of metal complex ions with opposite electrical charges is spontaneously loaded onto the carbon substrate and transformed into diatomic sites via thermal treatment. This noncovalent assembly approach shows universal feasibility for a broad spectrum of DACs (Ir–Fe, Pt–Fe, Pt–Co, and Pt–Ni). To prove the practical utility, the as‐prepared PtFe‐DAC is deployed as oxygen reduction reaction catalyst, performing excellent activity with a half‐wave potential of 0.935 V (vs RHE) and a 2.3 times higher turnover frequency than that of the single‐atomic Fe‐SAC. In situ characterization and theoretical calculation indicate that the adjacent Pt sites could endow moderate activation of oxygen molecule on Fe sites by lowering the electron pairing energy as well as the modulation of the d‐band center and spin states of Fe centers propelling the desorption of the intermediates. [ABSTRACT FROM AUTHOR]

A dilute plasma is continuously maintained in the troposphere by ionising particle radiation from galactic cosmic rays and radon decay. Small ions in the 1–2 nm size range play an important role in atmospheric processes such as ion-induced nucleation of aerosol particles. Consequently there is a need for precise and robust instruments to measure small ions both for atmospheric observations and for laboratory experiments that simulate the atmosphere. Here we describe the design and performance of the Cluster Ion Counter (CIC, Airel OÜ), which simultaneously measures the number concentrations of positively- and negatively-charged ions and particles below 5 nm mobility diameter, with low noise and fast time response. The detection efficiency is above 80 % for ions and charged particles between 1.2 and 2.0 nm, and above 90 % between 2.0 and 3.0 nm. The ion concentrations measured by the CIC agree well with reference instruments. The noise level (1 σ of background measurements) is typically between 20 and 30 ions cm-3 at 1 Hz sampling rate and an air flow rate of 7 l min-1 per analyzer. The noise level improves when higher flow rates and longer sampling periods are used. The CIC responds rapidly with 1 s time resolution to pulses of ionisation produced in the CLOUD chamber by a CERN particle beam. [ABSTRACT FROM AUTHOR]

Background: Traditional chemotherapeutic agents suffer from a lack of selectivity, poor targeting ability, and drug resistance. Developing tumor-specific therapies is crucial for precisely eliminating tumors while circumventing toxicity to normal tissues. Disulfiram (DSF), an FDA-approved drug for treating alcohol dependence, exhibits antitumor effect by forming complexes with copper ions (Cu(DDC)2). Here, we developed a Cu-doped polydopamine-based nanosystem (DSF@CuPDA-PEGM) to achieve in situ generation of toxic Cu(DDC)2. Results: In cancer cells with elevated H2O2 contents, CuPDA responsively degrades to release Cu ions and DSF, allowing on-site synthesis of Cu(DDC)2 with potent antitumor activity. DSF@CuPDA-PEGM exhibits excellent therapeutic efficacy against both drug-sensitive and drug-resistant cancer cells while minimizing toxicity to noncancerous cells. Moreover, DSF@CuPDA-PEGM promotes the immune response by inducing cancer cell immunogenic death, thereby augmenting anti-PD-1-based immune checkpoint blockade therapy. Conclusion: A tumor-specifically degradable Cu-doped polydopamine-based nanosystem is developed to achieve in situ synthesis of antitumor compounds, providing a promising approach to precisely eliminate tumors and heighten chemo-immunotherapy. [ABSTRACT FROM AUTHOR]

The utilization of thin zinc (Zn) anodes with a high depth of discharge is an effective strategy to increase the energy density of aqueous Zn metal batteries (ZMBs), but challenged by the poor reversibility of Zn electrode due to the serious Zn‐consuming side reactions at the Zn||electrolyte interface. Here, we introduce 2‐bromomethyl‐1,3‐dioxolane (BDOL) and methanol (MeOH) as electrolyte additive into aqueous ZnSO4 electrolyte. In the as‐formulated electrolyte, BDOL with a strong electron‐withdrawing group (−CH2Br) tends to pair with the H2O−Zn−MeOH complex, leading to the formation of organobromine‐partnered H2O−Zn−MeOH cluster ions. During the Zn electrodeposition process, the formed ZnO‐dominated by‐products induce the polymerization of BDOL monomers, which are previously adsorbed on the electrode. As a result, a uniform dual‐layer SEI with ZnO‐dominated outer layer and polyether‐dominated inner layer is built on the surface of Zn electrode. With such an in situ formed dual‐layer SEI, the Zn||Mg0.9Mn3O7 ⋅ 2.7H2O pouch cell using a 10‐um Zn anode (corresponding to a low negative to positive areal capacity ratio of 3.56) successfully operated for 300 cycles with a high capacity retention of 86 %, promising a high practical energy density of >120 Wh/kg (based on the total mass of Zn and Mg0.9Mn3O7 ⋅ 2.7H2O). [ABSTRACT FROM AUTHOR]

The evolution of ion channel clustering at nodes of Ranvier enabled the development of complex vertebrate nervous systems. At mammalian nodes, the K+ leak channels TRAAK and TREK-1 underlie membrane repolarization. Despite the molecular similarities between nodes and the axon initial segment (AIS), TRAAK and TREK-1 are reportedly node-specific, suggesting a unique clustering mechanism. However, we show that TRAAK and TREK-1 are enriched at both nodes and AIS through a common mechanism. We identified a motif near the C-terminus of TRAAK that is necessary and sufficient for its clustering. The motif first evolved among cartilaginous fish. Using AnkyrinG (AnkG) conditional knockout mice, CRISPR/Cas9-mediated disruption of AnkG, co-immunoprecipitation, and surface recruitment assays, we show that TRAAK forms a complex with AnkG and that AnkG is necessary for TRAAK’s AIS and nodal clustering. In contrast, TREK-1’s clustering requires TRAAK. Our results expand the repertoire of AIS and nodal ion channel clustering mechanisms and emphasize AnkG’s central role in assembling excitable domains. [ABSTRACT FROM AUTHOR]

We report the synthesis, structure, and characterization of two novel neptunyl complexes (NpO2L1 and NpO2L2) constructed from phenylene‐substituted benzyl ester bis(pyrrole)phenylenediamine (named "pyrrophen") ligands. In both cases, the neptunium center exists in the +6 oxidation state,. As our specific interest is in exploring the chemistry of neptunium compounds containing the linear neptunyl ion (NpO22+) through equatorially coordinating the metal by multidentate organic ligands, we have identified the differences that are likely to cause discrepancy between the two complexes by examining the ions and their coordinative environments through single‐crystal X‐ray crystallography, diffuse reflectance, and Raman spectroscopy. This is the first time pyrrophen has been utilized in Np chemistry and demonstrates a new platform to study 5 f electron participation and coordination. [ABSTRACT FROM AUTHOR]

Oxalate plays a crucial role in various biological and industrial applications. Its involvement in diseases, drug‐ and toxin‐induced disorders, and disruption of industrial processes makes it a high‐priority chemical for the development of more precise, selective, and straightforward analytical methods. Herein, an innovative and efficient strategy for sequentially measuring Cu2+ and oxalate ions is reported. During an indicator displacement process, where Cu2+ and azo dye, ArsenazoIII (AAIII), are used as receiver and indicator, respectively, oxalate (C2O42−) is measured by a colorimetric method. Proof of concept results from UV–visible spectroscopy, naked eye, and signal reset of the indicator revealed a more robust interaction of the Cu2+ receptor with C2O42− than the AAIII indicator with high selectivity, good sensitivity, and lower detection limit(4.01 × 10−8 and 3.04 × 10−9mol L−1, for Cu2+ and C2O42−, respectively). The results of measuring C2O42− in actual samples (urine, mushrooms, and spinach) showed the applicability of the existing method. Most importantly, the colorimetric system based on molecular exchange in the indicator dislocation proceeding can serve as a colorimetric INHIBIT logic‐gate. It works like a molecular keypad lock system that can be controlled by two users with two different sets of chemical passwords (inputs) that can be identified through optical paths. [ABSTRACT FROM AUTHOR]