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Redox potentials depend on the nature of the solvent/electrolyte through the solvation energies of the ionic solute species. For concentrated electrolytes, ion solvation may deviate significantly from the Born model predictions due to ion pairing and correlation effects. Recently, Ghorai and Matyushov [J. Phys. Chem. B 124, 3754–3769 (2020)] predicted, on the basis of linear response theory, an anomalous trend in the solvation energies of room temperature ionic liquids, with deviations of hundreds of kJ/mol from the Born model for certain size solutes/ions. In this work, we computationally evaluate ionic solvation energies in the prototypical ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM/BF4), to further explore this behavior and benchmark several of the approximations utilized in the solvation energy predictions. For comparison, we additionally compute solvation energies within acetonitrile and molten NaCl salt to illustrate the limiting behavior of purely dipolar and ionic solvents. We find that the overscreening effect, which results from the inherent charge oscillations of the ionic liquid, is substantially reduced in magnitude due to screening from the dipoles of the molecular ions. Therefore, for the molten NaCl salt, for which the ions do not have permanent dipoles, modulation of ionic solvation energies from the overscreening effect is most significant. The conclusion is that ionic liquids do indeed exhibit unique solvation behavior due to peak(s) in the electrical susceptibility caused by the ion shell structure; redox potential shifts for BMIM/BF4 are of more modest order ∼0.1 V, but may be larger for other ionic liquids that approach molten salt behavior. [ABSTRACT FROM AUTHOR]

Taking into account the electron-rich and visible light response of thiophene, first-principles calculations have been carried out to explore the photocatalytic activity of donor–acceptor polymers incorporating thiophene and boron. Honeycomb-kagome boron–thiophene (BTP) polymers with varying numbers of thiophene units and fixed B center atoms are direct bandgap semiconductors with tunable bandgaps ranging from 2.41 to 1.88 eV and show high absorption coefficients under the ultraviolet and visible regions of the solar spectrum. Fine-tuning the band edges of the BTP polymer is efficiently achieved by adjusting the pore size through the manipulation of thiophene units between the B centers. This manipulation, achieved without excessive chemical functionalization, facilitates the generation of an appropriate quantity of photoexcited electrons and/or holes to straddle the redox potential of the water. Our study demonstrates that two units between B centers of thiophene in BTP polymers enable overall photocatalytic water splitting, whereas BTP polymers with larger pores solely promote photocatalytic hydrogen reduction. Moreover, the thermodynamics of hydrogen and oxygen reduction reactions either proceed spontaneously or need small additional external biases. Our findings provide the rationale for designing metal-free and single-material polymer photocatalysts based on thiophene, specifically for achieving efficient overall water splitting. [ABSTRACT FROM AUTHOR]

Electrochemical and photochemical hydrogen (H2) evolution activities of a 6-fluoro-2-hydroxypyridinate (fhp−)-bridged paddlewheel-type dirhodium (Rh2) complex, [Rh2(fhp)4], were investigated through experimental and theoretical approaches. In DMF, the [Rh2(fhp)4] underwent a one-electron reduction (assigned to Rh24+/3+) at −1.31 V vs SCE in the cathodic region. Adding trifluoroacetic acid as a proton source to the electrochemical cell containing [Rh2(fhp)4], the significant catalytic current, i.e., electrochemical H2 evolution, was observed; the turnover frequency and overpotential of electrochemical H2 evolution were 18 244 s−1 and 732 mV, respectively. The reaction mechanism of electrochemical H2 evolution catalyzed by [Rh2(fhp)4] in DMF was examined in detail by theoretically predicting the redox potentials and pKa values of the reaction intermediates using density functional theory calculations. The calculations revealed that (i) the formation of a one-electron reduced species, [Rh2(fhp)4]−, triggered for H2 evolution and (ii) the protonation and reduction processes of [Rh2(fhp)4]− to further reduced hydride intermediates proceeded directly via a concerted proton–electron transfer mechanism. Moreover, [Rh2(fhp)4] was shown to be a highly efficient H2 evolution catalyst (HEC) for photochemical proton reduction reactions when combined with an artificial photosynthetic (AP) system containing [Ir(ppy)2(dtbbpy)]PF6 and triethylamine, which served as a photosensitizer and a sacrificial electron donor, respectively. Under visible light irradiation, the total amount of H2 evolved and its turnover number (per Rh ion) were 1361.0 µmol and 13 610, respectively, which are superior to those of previously reported AP systems with rhodium complexes as HEC. [ABSTRACT FROM AUTHOR]

Superconcentrated aqueous electrolytes have recently emerged as a new class of electrolytes, called water-in-salt electrolytes. They are distinguished, in both weight and volume, by a quantity of salt greater than water. Currently, these electrolytes are attracting major interest, particularly for application in aqueous rechargeable batteries. These electrolytes have only a small amount of free water due to an ultrahigh salt concentration. Consequently, the electrochemical stability window of water is wider than the predicted thermodynamic value of 1.23 V. Hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have been shown to be shifted to more negative and positive potentials, respectively. The decrease in free water population is recognized as being involved in the increase in the electrochemical stability window of water. Here, we study the quantitative contribution of the decrease in the free water molecule concentration to the permittivity of the solution and of the activity of water to the OER and HER overpotentials when the salt concentration increases. We compare our model with that of Kornyshev and get three types of electrolyte structures: diluted, gradient of water contents, and aggregation. The theoretical calculation of the redox potentials of the OER and HER is compared with the experimentally determined electrochemical properties of aqueous LiTFSI electrolytes. [ABSTRACT FROM AUTHOR]

Owing to the low redox potential (−3.040 V vs. SHE) and high theoretical specific capacity (3860 mA h g−1), lithium metal is regarded as the 'holy grail" anode for energy storage systems. However, traditional porous polypropylene (PP) separators cause inhomogeneous flux of lithium ions, leading to lithium dendrites and unstable byproducts (known as "dead lithium"). In the work, a composite coating consisting of lithium ion conductor Li1+xAlxTi2−x(PO4)3 (LATP) and polymer polyvinylidene fluoride–hexafluoropropylene (PVDF–HFP) is proposed. The conductive LATP nanoparticles regulate the lithium ion flux and induce homogeneous lithium metal deposition. The flexible PVDF–HFP/LATP coating layer reduces the energy barrier for Li deposition and enables fast kinetics at the interface. As a result, stable and high rate performance lithium metal batteries are achieved. With an areal capacity of 1 mA h cm−2, Li‖‖Li symmetric batteries cycled steadily with very low overpotentials for over 850 h at a current density of 1 mA cm−2, and at the 520th cycle, the battery with a modified separator exhibited a capacity of 156 mA h g−1 (capacity retention of 88.6%). In the rate test, the modified batteries exhibited a capacity of 145.9 mA h g−1 at a high rate of 4C, which suggests that the modified separator results in uniform and dendrite-free Li deposition and stripping as well as fast kinetics. [ABSTRACT FROM AUTHOR]

3‐methyl‐4‐(hetero)arylmethylidene isoxazole‐5(4H)‐one derivatives (4a‐r) derivatives (4a‐r) were synthesized by the multi‐component reactions. The multi‐component reactions (MCRs) of hydroxylamine hydrochloride, ethyl acetoacetate and aromatic/ heteroaromatic aldehyde catalyzed by novel Glutamic acid (Glu) as a biodegradable and eco‐friendly organocatalyst in ethanol on oil bath stirring at 60 °C. The final product homogeneity was examined by various spectroscopic techniques. In this work prepared compounds 4 q and 4 r are novel derivatives. The molecular dynamics of total energy and energy gap was calculated using DFT/B3LYP/6–31G (dp) method. The selected derivatives (4 l–r) screened against in vitro MCF‐7 breast cancer cell line by MTT assay, derivatives 4 l and 4 o displayed very good activity with IC50 of 6.57±2.31, and 21.93±1.34 as compared to doxorubicin of IC50 (3.69±0.17). Molecular docking studies were performed to evaluate interaction of PDB id: 1 M17 with led molecules of MCF‐7. Later, 1 M17 and 4 l underwent 200 ns molecular dynamics and simulation within physiological conditions, the outcomes showed that during the simulation, the ligand stayed in the same form. Further, the selected derivatives drug like computed using swissADME, and derivatives 4 l–r obeyed rule of Lipinski's. Furthermore, selected derivatives tested for electrochemical behavior using cyclic voltammetry, and compound 4 l and 4 q showed strong oxidation and reduction potential, thus these derivatives can present better antioxidant properties. [ABSTRACT FROM AUTHOR]

Azobenzenes (ABs) are versatile compounds featured in numerous applications for energy storage systems, such as solar thermal storages or phase change materials. Additionally, the reversible one‐electron reduction of these diazenes to the nitrogen‐based radical anion has been used in battery applications. Although the oxidation of ABs is normally irreversible, 4,4'‐diamino substitution allows a reversible 2e− oxidation, which is attributed to the formation of a stable bis‐quinoidal structure. Herein, we present a system that shows a bipolar redox behaviour. In this way, ABs can serve not only as anolytes, but also as catholytes. The resulting redox potentials can be tailored by suitable amine‐ and ring‐substitution. For the first time, the solid‐state structure of the oxidized form could be characterized by X‐ray diffraction. [ABSTRACT FROM AUTHOR]

Design of metal cofactor ligands is essential for controlling the reactivity of metalloenzymes. We investigated a carbene transfer reaction catalyzed by myoglobins containing iron porphyrin cofactors with one and two trifluoromethyl groups at peripheral sites (FePorCF3 and FePor(CF3)2, respectively), native heme and iron porphycene (FePc). These four myoglobins show a wide range of Fe(II)/Fe(III) redox potentials in the protein of +147 mV, +87 mV, +42 mV and −198 mV vs. NHE, respectively. Myoglobin reconstituted with FePor(CF3)2 has a more positive potential, which enhances the reactivity of a carbene intermediate with alkenes, and demonstrates superior cyclopropanation of inert alkenes, such as aliphatic and internal alkenes. In contrast, engineered myoglobin reconstituted with FePc has a more negative redox potential, which accelerates the formation of the intermediate, but has low reactivity for inert alkenes. Mechanistic studies indicate that myoglobin with FePor(CF3)2 generates an undetectable active intermediate with a radical character. In contrast, this reaction catalyzed by myoglobin with FePc includes a detectable iron–carbene species with electrophilic character. This finding highlights the importance of redox‐focused design of the iron porphyrinoid cofactor in hemoproteins to tune the reactivity of the carbene transfer reaction. [ABSTRACT FROM AUTHOR]

We devised a quantum chemical simulation protocol that can rapidly and accurately predict ground and excited state reduction potentials (E0 and E*, respectively) of acridinium photoredox catalysts (PCs). To bypass time‐consuming excited state geometry optimizations, we used ground state equilibrium geometries to compute the electronic energy of excited states, which provides reasonable E0 and E* estimates. The contribution of Hartree‐Fock exchange (HFX) in density functionals was systematically varied to estimate E0 and E*. In addition to reproducing experimental results, physically sensible models, such as correct descriptions of exciton behavior, are highly necessary. Based on the exciton correlation values, the appropriate amount of HFX in the B3LYP functional was determined to be 30 % to yield physically sensible bound electron‐hole pairs for small organic molecules. We also investigated the impact of basis sets on the predictability of E0 and E*. Geometry optimizations with B3LYP‐D2(HFX 20 %)/6‐31G and single point energy refinement with (TD‐)B3LYP‐D2(HFX 30%)/6‐311++G(d,p) yielded the best results. The transferability of the suggested protocol was confirmed with a test set consisting of eight acridinium derivatives. This study can provide reasonably accurate results with relatively small amounts of computational resources, and it is therefore expected to greatly contribute to the development of new acridinium PCs. [ABSTRACT FROM AUTHOR]

The increase in pesticide regulations, diminished pesticide options due to resistance concerns, and narrowing grower profit margins require each application to be optimised to reduce spray drift and enhance coverage. However, alternative strategies outside of increasing droplet size are needed as reductions in pest control have been observed. This research explored the potential of a magnetic-assisted sprayer (MAS) to aid in spray coverage and determine its impact on spray droplet size and velocity. The MAS minimally impacted spray droplet size characteristics across the four nozzle types tested (only five of twenty F-tests were statistically significant) and did not impact average or maximum droplet velocities when measured 51-cm from the nozzle compared to the conventional sprayer. Although statistically, the MAS increased droplet size by only 4.6 and 12.5% in two of 12 parameter instances compared to the conventional sprayer, there were indications it may reduce spray drift potential as the driftable fines (% of individual droplets measured with diameters less than 200 μm) were numerically less across all nozzle types tested. Across the five experiments, an improvement in spray coverage and deposition by the MAS compared to the conventional sprayer was only observed in one treatment from one experiment. Overall, the MAS minimally to negatively impacted the measured coverage and calculated deposition from water-sensitive paper. Future research is needed to measure actual spray drift from a MAS as well as to evaluate other potentially influential variables such as water quality, pesticide active ingredient, and plant species. • Magnetic-assist increased droplet size in 2 of 12 comparisons with a stock sprayer. • Slight drift reduction potential (reduced fines in 1 of 4 comparisons) observed. • Droplet velocity was not altered by a magnetic-assisted sprayer. • Coverage and deposition improved in 1 of 58 treatments compared to a stock sprayer. • Future research should evaluate more spray variables combined with magnetic effect. [ABSTRACT FROM AUTHOR]

The electrochemical coupling of biomass oxidation and nitrogen conversion presents a potential strategy for high value‐added chemicals and nitrogen cycling. Herein, in this work, CuO/Co3O4 with heterogeneous interface is successfully constructed as a bifunctional catalyst for the electrooxidation of 5‐hydroxymethylfurfural to 2,5‐furandicarboxylic acid and the electroreduction of nitrate to ammonia (NH3). The open‐circuit potential spontaneous experiment shows that more 5‐hydroxymethylfurfural molecules are adsorbed in the Helmholtz layer of the CuO/Co3O4 composite, which certifies that the CuO/Co3O4 heterostructure is conducive to the kinetic adsorption of 5‐hydroxymethylfurfural. In situ electrochemical impedance spectroscopy further shows that CuO/Co3O4 has faster reaction kinetics and lower reaction potential in oxygen evolution reaction and 5‐hydroxymethylfurfural electrocatalytic oxidation. Moreover, CuO/Co3O4 also has a good reduction effect on NO3−. The ex‐situ Raman spectroscopy shows that under the reduction potential, the metal oxide is reduced, and the generated Cu2O can be used as a new active site for the reaction to promote the electrocatalytic conversion of NO3− to NH3 synthesis. This work provides valuable guidance for the synthesis of value‐added chemicals by 5‐hydroxymethylfurfural electrocatalytic oxidation coupled with NO3− while efficiently producing NH3. [ABSTRACT FROM AUTHOR]

Most organic electrode materials (OEMs) for rechargeable batteries employ n‐type redox centers, whose redox potentials are intrinsically limited <3.0 V versus Li+/Li. However, p‐type materials possessing high redox potentials experience low specific capacities because they are capable of only a single redox reaction within the stable electrochemical window of typical electrolytes. Herein, we report 5,11‐diethyl‐5,11‐dihydroindolo[3,2‐b]carbazole (DEICZ) as a novel p‐type OEM, exhibiting stable plateaus at high discharge potentials of 3.44 and 4.09 V versus Li+/Li. Notably, the second redox potential of DEICZ is within the stable electrochemical window. The mechanism of the double redox reaction is investigated using both theoretical calculations and experimental measurements, including density functional theory calculations, ex situ electron spin resonance, and X‐ray photoelectron spectroscopy. Finally, hybridization with single‐walled carbon nanotubes (SWCNT) improves the cycle stability and rate performance of DEICZ owing to the π–π interactions between the SWCNT and co‐planar molecular structure of DEICZ, preventing the dissolution of active materials into the electrolyte. The DEICZ/SWCNT composite electrode maintains 70.4% of its initial specific capacity at 1‐C rate and also exhibits high‐rate capability, even performing well at 100‐C rate. Furthermore, we demonstrate its potential for flexible batteries after applying 1000 bending stresses to the composite electrode. [ABSTRACT FROM AUTHOR]

Calcium‐ion batteries have been considered attractive candidates for large‐scale energy storage applications due to their natural abundance and low redox potential of Ca2+/Ca. However, current calcium ion technology is still hampered by the lack of high‐capacity and long‐life electrode materials to accommodate the large Ca2+ (1.00 Å). Herein, an amorphous vanadium structure induced by Mo doping and in‐situ electrochemical activation is reported as a high‐rate anode material for calcium ion batteries. The doping of Mo could destroy the lattice stability of VS4 material, enhancing the flexibility of the structure. The following electrochemical activation further converted the material into sulfide and oxides co‐dominated composite (defined as MoVSO), which serves as an active material for the storage of Ca2+ during cycling. Consequently, this amorphous vanadium structure exhibits excellent rate capability, achieving discharge capacities of 306.7 and 149.2 mAh g−1 at 5 and 50 A g−1 and an ultra‐long cycle life of 2000 cycles with 91.2% capacity retention. These values represent the highest level to date reported for calcium ion batteries. The mechanism studies show that the material undergoes a partial phase transition process to derive MoVSO. This work unveiled the calcium storage mechanism of vanadium sulfide in aqueous electrolytes and accelerated the development of high‐performance aqueous calcium ion batteries. [ABSTRACT FROM AUTHOR]

Structural differences between illuminated and unilluminated crystal structures led to the proposal that the charge-separated state was stabilized by structural changes in its membrane extrinsic protein subunit H in a bacterial photosynthetic reaction center [Katona, G. et al. Nat. Struct. Mol. Biol. 2005, 12, 630–631]. Here, we explored the proposal by titrating all titratable sites and calculating the redox potential (Em) values in these crystal structures. Contrary to the expected charge-separated states, Em for quinone, Em(QA/QA•–), is even lower in the proposed charge-separated structure than in the ground-state structure. The subunit-H residues, which were proposed to exhibit electron-density changes in the two crystal structures, contribute to an Em(QA/QA•–) difference of only <0.5 mV. Furthermore, the protonation states of the titratable residues in the entire reaction center are practically identical in the two structures. These findings indicate that the proposed structural differences are irrelevant to explaining the significant prolongation of the charge-separated-state lifetime. In bacterial photosynthetic reactions, charge-separated states are thought to be stabilized by structural changes in the membrane extrinsic protein subunit H. Here, the authors probe all titratable sites and calculate values of cofactors, and find that the redox potential for quinone is lower in the proposed charge-separated than in the ground-state structure and that the subunit-H residues contribute to a redox potential difference below 0.5 mV. [ABSTRACT FROM AUTHOR]

Organic dyes hold promise as inexpensive electrochemically‐active building blocks for new renewable energy technologies such as redox‐flow batteries and dye‐sensitised solar cells, especially if they display high oxidation and/or low reduction potentials in cheap, non‐flammable solvents such as water or protic ionic liquids. Systematic computational and experimental characterisation of a representative selection of acidic and basic dyes in buffered aqueous solutions and propylammonium formate confirm that quinoid‐type mechanisms impart electrochemical reversibility for the majority of systems investigated, including quinones, fused tricyclic heteroaromatics, indigo carmine and some aromatic nitrogenous species. Conversely, systems that generate longlived radical intermediates – arylmethanes, hydroquinones at high pH, azocyclic systems – tend to display irreversible electrochemistry, likely undergoing ring‐opening, dimerisation and/or disproportionation reactions. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal batteries have attracted great attention as next‐generation high‐energy‐density storage systems due to the high theoretical energy density and low redox potential of Li metal. However, the safety concerns and poor cycle life are hindering the commercialization of Li metal batteries. Combination of Li metal and current collectors to regulate Li plating/stripping behaviors is an effective strategy to address these issues. In this review, the recent advances in the current collectors for composite Li metal anodes are summarized, including construction interfacial protective layers on current collectors, fabrication and utilization of 3D current collectors, and improving the surface lithiophilicity for current collectors. Finally, perspectives of the current limitations and the future research directions are also presented. [ABSTRACT FROM AUTHOR]

The formation of heterojunctions has been identified as the most promising strategy for circumventing the constraints of the g-C 3 N 4 photocatalyst, including sluggish surface kinetics and rapid recombination loss of photoexcited electron and hole pairs. Combining g-C 3 N 4 with other semiconductors to form S-scheme heterojunctions can boost charge carrier surface migration, reduce recombination loss, and maintain high redox potentials, which synergistically improve the photocatalytic performance of g–C 3 N 4 –based systems. However, as the development and understanding of g–C 3 N 4 –based S-scheme catalysts has advanced, several conflicts and confusions have emerged, which must be clarified to widen the scope applicability of g–C 3 N 4 –based photocatalysts. To understand whether the charge migration route in g–C 3 N 4 –based heterojunctions is type-II or S-scheme, this review includes a systematic discussion with the support of theoretical models and advanced experimental techniques that illustrate the requirements for building type-II and S-scheme charge migration. Furthermore, in contrast to the conventional role, the actual function of Fermi levels bending at equalization in g–C 3 N 4 –based S-scheme heterojunctions to provide the potential difference for maintaining the interfacial built-in electric field, the persistence of driving, and strategies to strengthen the driving force are explained in depth. The current review offers fresh insights into the criteria used to establish the prerequisites for the creation of g–C 3 N 4 –based type-II and S-scheme heterojunctions. • Confusion between g–C 3 N 4 –based S-scheme and type-II charge migration route is clarified. • The actual role of Fermi levels instead of ideal in g-C 3 N 4 S-scheme heterojunction is discussed. • The persistence of driving force in g–C 3 N 4 –based S-scheme heterojunctions and associated strategies are introduced. • Characterization techniques to identify the S-scheme charge migration route are described. [ABSTRACT FROM AUTHOR]

Because hepatic stellate cells (HSCs) play a major role in fibrosis, we focused on HSCs as a potential target for the treatment of liver fibrosis. In this study, we attempted to identify drug candidates to inactivate HSCs and found that several proteasome inhibitors (PIs) reduced HSC viability. Our data showed that a second-generation PI, carfilzomib (CZM), suppressed the expression of fibrotic markers in primary murine HSCs at low concentrations of 5 or 10 nM. Since CZM was not toxic to HSCs up to a concentration of 12.5 nM, we examined its antifibrotic effects further. CZM achieved a clear reduction in liver fibrosis in the carbon tetrachloride (CCl4)-induced mouse model of liver fibrosis without worsening of liver injury. Mechanistically, RNA sequence analysis of primary HSCs revealed that CZM inhibits mitosis in HSCs. In the CCl4-injured liver, amphiregulin, which is known to activate mitogenic signaling pathways and fibrogenic activity and is upregulated in murine and human metabolic dysfunction-associated steatohepatitis (MASH), was downregulated by CZM administration, leading to inhibition of mitosis in HSCs. Thus, CZM and next-generation PIs in development could be potential therapeutic agents for the treatment of liver fibrosis via inactivation of HSCs without liver injury. [ABSTRACT FROM AUTHOR]

Among available techniques for lateral tracking in autonomous driving, none possesses the capability to learn from past behaviors and progressively reduce lateral errors. In contrast, our proposed iterative learning control (ILC) scheme significantly enhances tracking performance in vision-based classical control, particularly in challenging environmental conditions. Our vision-based control system incorporates real-time semantic segmentation using the ENet model for unconstructed road area extraction. Linear regression estimates steering adjustments, while a visual PID controller maintains the vehicle’s position at the road’s centerline. This control system’s performance varies with lighting conditions, notably in dense shade, where the vehicle tends to deviate from the desired path. To assess ILC’s potential in error reduction over successive trials, we examined various ILC structures and compared them with a pure PID controller. Despite challenges in directly comparing PID and ILC designs due to changing lighting conditions during experiments, ILC consistently reduced tracking errors and improved path alignment with each iteration. Notably, the degree of error reduction became more pronounced with a greater number of learning gains in the ILC design. Our experimental results underscore the overall effectiveness of ILC in tracking the desired path in autonomous driving scenarios, particularly in varying environmental conditions. [ABSTRACT FROM AUTHOR]

The synthesis of three novel [C,N,N′] Pt(IV) cyclometallated compounds containing hydroxo, dichloroacetato or trifluoroacetato axial ligands is reported. Compound [PtCl(OH)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (3) was prepared by the oxidative addition of hydrogen peroxide to [C,N,N′] Pt(II) cyclometallated compound [PtCl{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (1) and further the reaction of compound 3 with dichloroacetate or trifluoroacetate anhydrides led to the formation of the corresponding compounds [PtCl(CHCl2COO)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (4) and [PtCl(CF3COO)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (5). The properties of the new compounds along with those of the compound [PtCl3{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (2), including stability in aqueous media, reduction potential using cyclic voltammetry, cytotoxic activity against the HCT116 CRC cell line, DNA interaction, topoisomerase I and cathepsin inhibition, and computational studies involving reduction of the Pt(IV) compounds and molecular docking studies, are presented. Interestingly, the antiproliferative activity of these compounds against the HCT116 CRC cell line, which is in all cases higher than that of cisplatin, follows the same trend as the reduction potentials so that the most easily reduced compound 2 is the most potent. In contrast, according to the electrophoretic mobility and molecular docking studies, the efficacy of these compounds in binding to DNA is not related to their cytotoxicity. The most active compound 2 does not modify the DNA electrophoretic mobility while the less potent compound 3 is the most efficient in binding to DNA. Although compounds 2 and 3 have only a slight effect on cell cycle distribution and apoptosis induction, generation of ROS to a higher extent for the most easily reduced compound 2 was observed. [ABSTRACT FROM AUTHOR]

A modified (2, 2, 6, 6-tetramethylpiperidin-1-yl) oxyl (TEMPO) was developed for use as an organic mediator in chemically regenerative redox fuel cells (CRRFC). The main challenge of CRRFC is to determine the optimal redox molecule in terms of redox potential, stability, and fast regeneration kinetics. In order to avoid crossover of the TEMPO-based organic mediator through the membrane, the electroactive specie was functionalized with polyethylene glycol (PEG) chains of different lengths and the electrochemical properties of the synthesized species were assessed. Such chemical modification prevents the crossover of the redox mediators through the membrane, as demonstrated by ex situ analytical electrochemistry. The developed fuel cell provided a maximum power density of 110 mW cm−2 (150 mA cm−2 at 0.6 V) with TEMPO-based mediators bearing PEG chains, while exhibiting a higher stability than a cell using a commercial reference mediator. This study opens the route to design and select new organic mediators for applications in CRRFC and further improvements to enhance their stability over time. • A new class of molecule were synthesized and implemented in chemically regenerative redox fuel cell. • The organic synthesis of electroactive molecule avoid the crossover of the molecule through the membrane. • Improved stability of fuel cell performance was reached with modified TEMPO based catholyte. [ABSTRACT FROM AUTHOR]

Mangrove forests are fundamental coastal ecosystems for the variety of services they provide, including green-house gas regulation, coastal protection and home to a great biodiversity. Mexico is the fourth country with the largest extension of mangroves of which 60% occurs in the Yucatan Peninsula. Understanding the microbial component of mangrove forests is necessary for their critical roles in biogeochemical cycles, ecosystem health, function and restoration initiatives. Here we study the relation between the microbial community from sediments and the restoration process of mangrove forests, comparing conserved, degraded and restored mangroves along the northern coast of the Yucatan peninsula. Results showed that although each sampling site had a differentiated microbial composition, the taxa belonged predominantly to Proteobacteria (13.2–23.6%), Desulfobacterota (7.6–8.3%) and Chloroflexi (9–15.7%) phyla, and these were similar between rainy and dry seasons. Conserved mangroves showed significantly higher diversity than degraded ones, and restored mangroves recovered their microbial diversity from the degraded state (Dunn test p-value Benjamini-Hochberg adjusted = 0.0034 and 0.0071 respectively). The structure of sediment microbial β-diversity responded significantly to the mangrove conservation status and physicochemical parameters (organic carbon content, redox potential, and salinity). Taxa within Chloroflexota, Desulfobacterota and Thermoplasmatota showed significantly higher abundance in degraded mangrove samples compared to conserved ones. This study can help set a baseline that includes the microbial component in health assessment and restoration strategies of mangrove forests. [ABSTRACT FROM AUTHOR]

Phenolic compounds have long captivated the interest of organic synthesis, particularly in their quest for selective hydroxylation of arenes using H2O as a hydroxyl source. However, the inherent high reactivity and low redox potential of phenols often lead to undesirable overoxidation byproducts. To address this challenge, herein, we develop an electrophotochemical approach, finetuning substrate oxidative potential and enabling para-selective hydroxylation of anilides. This method showcases versatility, accommodating a wide array of substrates, while revealing high regional selectivity and compatibility with diverse functional groups. Moreover, the protocol allows facile late-stage functionalization of biologically active molecules. Mechanistic investigations demonstrate the activation of anilides by the excited state photocatalyst, effectively decreasing their oxidative potential and enhancing regional selectivity during hydroxylation. By using this protocol, important drug molecules such as Paracetamol, Fenretinide, Practolol, and AM404 could be synthesized, demonstrating the applicability of this approach in drug synthesis and late-stage functionalization. Phenolic compounds have long captivated the interest of organic synthesis, particularly in their quest for selective hydroxylation of arenes using H2O as a hydroxyl source but the inherent high reactivity and low redox potential of phenols often lead to undesirable overoxidation byproducts. Here the authors develop an electrophotochemical approach, finetuning substrate oxidative potential and enabling para-selective hydroxylation of anilides. [ABSTRACT FROM AUTHOR]

AbstractSalinity is harmful for crop development and productivity. The adoption of intercropping practice and microbial auxiliaries can combat the harmful actions of salt stress. The present study aimed to investigate the role of intercropping and co-application of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) to protect barley and alfalfa against salt stress (120 mM NaCl). Results revealed that, under saline conditions, the applied intercropping system and AMF + PGPR co-inoculation enhanced shoot and root dry weight by 133% and 354% for barley and 410% and 471% for alfalfa, respectively, over their respective non-inoculated monocultures. Meanwhile, as compared to non-inoculated monocultures, the association of intercropping and AMF + PGPR co-application boosted antioxidant enzymes activity, namely superoxide dismutase and catalase, by 161% and 63% for barley and 316% and 113% for alfalfa, respectively. Additionally, the thousand-seed weight was increased by 77% in barley intercropped and inoculated with AMF + PGPR. This study highlights the potential of intercropping and AMF + PGPR as a promising solution to improve salt tolerance and crop productivity by increasing physiological capacity, boosting nutrient acquisition, and enhancing redox potential. [ABSTRACT FROM AUTHOR]

The present work focuses on comparing the performance of novel cationic graft copolymer polyvinylpyrrolidone-graft-poly(acrylamide-co-diallyldimethylammonium chloride) (PVP-g-p(AM-co-DADMAC)) synthesized via microwave-assisted technique, with varying amounts of monomers acrylamide (AM) and diallyldimethylammonium chloride (DADMAC) as a flocculant for sugarcane juice. The intended grafting was supported by extensive characterization of the material by various physicochemical methods. As compared to only AM or DADMAC grafted onto PVP, grafted copolymer with highest DADMAC-to-AM ratio was found to be more effective in removing colloids from fresh unaltered cane juice. The mode of action of the synthesized flocculant was explained by synergistic bridging and charge neutralization mechanism. The best grade of PVP-g-p(AM-co-DADMAC) at an optimum dose of only four ppm (within US FDA approved limit) showed a good reduction in the zeta potential (− 7.8 to − 2.9 mV) of the juice along with the formation of large-size floc (618 nm) without affecting the percentage of natural sugar content (degree brix- °bx). [ABSTRACT FROM AUTHOR]

Antimicrobial resistance has become a global threat to human health, which is coupled with the lack of novel drugs. Metallocompounds have emerged as promising diverse scaffolds for the development of new antibiotics. Herein, we prepared some metal compounds mainly focusing on cis-[Ru(bpy)(dppz)(SO3)(NO)](PF6) (PR02, bpy = 2,2′-bipyridine, dppz = dipyrido[3,2-a:2′,3′-c]phenazine), in which phenazinic and nitric oxide ligands along with sulfite conferred some key properties. This compound exhibited a redox potential for bound NO+/0 of −0.252 V (vs. Ag‖AgCl) and a high pH for nitrosyl-nitro conversion of 9.16, making the nitrosyl ligand the major species. These compounds were still able to bind to DNA structures. Interestingly, reduced glutathione (GSH) was unable to promote significant NO/HNO release, an uncommon feature of many similar systems. However, this reducing agent was essential to generate superoxide radicals. Antimicrobial studies were carried out using six bacterial strains, where none or very low activity was observed for Gram-negative bacteria. However, PR02 and PR (cis-[Ru(bpy)(dppz)Cl2]) showed high antibacterial activity in some Gram-positive strains (MBC for S. aureus up to 4.9 μmol L−1), where the activity of PR02 was similar to or at least 4-fold better than that of PR. Besides, PR02 showed capacity to inhibit bacterial biofilm formation, a major health issue leading to bacterial tolerance to antibiotics. Interestingly, we also showed that PR02 can function in synergism with the known antibiotic ampicillin, improving their action up to 4-fold even against resistant strains. Altogether, these results showed that PR02 is a promising antimicrobial nitrosyl ruthenium compound combining features beyond its killing action, which deserves further biological studies. [ABSTRACT FROM AUTHOR]

The "cloud lab," an automated laboratory that allows researchers to program and conduct physical experiments remotely, represents a paradigm shift in scientific practice. This shift from wet‐lab research as a primarily manual enterprise to one more akin to programming bears incredible promise by democratizing a completely new level of automation and its advantages to the scientific community. Moreover, they provide a foundation on which automated science driven by artificial intelligence (A.I.) can be built upon and thereby resolve limitations in scope and accessibility that current systems face. With a focus on DNA nanotechnology, the authors have had the opportunity to explore and apply the cloud lab to active research. This perspective delves into the future potential of cloud labs in accelerating scientific research and broadening access to automation. The challenges associated with the technology in its current state are further explored, including difficulties in experimental troubleshooting, the limited applicability of its parallelization in an academic setting, as well as the potential reduction in experimental flexibility associated with the approach. [ABSTRACT FROM AUTHOR]

The integration of hostless battery‐like metal anodes for hybrid supercapacitors is a realistic design method for energy storage devices with promising future applications. With significant Cr element deposits on Earth, exceptionally high theoretical capacity (1546 mAh g−1), and accessible redox potential (−0.74 V vs. reversible hydrogen electrode) of Cr metals, the design of Cr anodes has rightly come into our focus. This work presents a breakthrough design of a flexible Cr‐ion hybrid supercapacitor (CHSC) based on a porous graphitized carbon fabric (PGCF) substrate prepared by K2FeO4 activation. In the CHSC device, PGCF acts as both a current collector and cathode material due to its high specific surface area and superior conductivity. The use of a highly concentrated LiCl−CrCl3 electrolyte with high Cr plating/stripping efficiency and excellent antifreeze properties enables the entire PGCF‐based CHSC to achieve well‐balanced performance in terms of energy density (up to 1.47 mWh cm−2), power characteristics (reaching 9.95 mW cm−2) and durability (95.4 % capacity retention after 30,000 cycles), while realizing it to work well under harsh conditions of −40 °C. This work introduces a new concept for low‐temperature energy storage technology and confirms the potential application of Cr anodes in hybrid supercapacitors. [ABSTRACT FROM AUTHOR]

Li metal is regarded as the "Holy Grail" in the next generation of anode materials due to its high theoretical capacity and low redox potential. However, sluggish Li ions interfacial transport kinetics and uncontrollable Li dendrites growth limit practical application of the energy storage system in high‐power device. Herein, separators are modified by the addition of a coating, which spontaneously grafts onto the Li anode interface for in situ lithiation. The resultant alloy possessing of strong electron‐donating property promotes the decomposition of lithium bistrifluoromethane sulfonimide in the electrolyte to form a LiF‐rich alloy‐doped solid electrolyte interface (SEI) layer. High ionic alloy solid solution diffusivity and electric field dispersion modulation accelerate Li ions transport and uniform stripping/plating, resulting in a high‐power dendrite‐free Li metal anode interface. Surprisingly, the formulated SEI layer achieves an ultra‐long cycle life of over 8000 h (20,000 cycles) for symmetric cells at a current density of 10 mA cm−2. It also ensures that the NCM(811)//PP@Au//Li full cell at ultra‐high currents (40 C) completes the charging/discharging process in only 68 s to provide high capacity of 151 mAh g−1. The results confirm that this scalable strategy has great development potential in realizing high power dendrite‐free Li metal anode. [ABSTRACT FROM AUTHOR]

We report Cu, Fe, N‐doped carbon nanotubes, (Cu,Fe)−N−CNT, as electrocatalysts for the oxygen reduction reaction (ORR) in acidic media. (Cu,Fe)−N−CNT was prepared using a silica coating method in pyrolysis to minimize the formation of carbon‐coated metal oxide or carbide nanoparticles, which are known to be inactive for the H2O2 reduction. (Cu,Fe)−N−CNT shows a turnover frequency of 0.66 e− site−1 s−1 at +0.8 V vs. RHE and H2O2 yields of <1 % for the ORR with a utilization factor of active sites of 82 %. Kinetic analysis reveals that 4e− transfer rates for (Cu,Fe)−N−CNT are higher than those of a monometallic counterpart of Fe−N−CNT. In situ X‐ray absorption spectroscopy enables us to determine redox potentials: E°'(FeIII/FeII)=0.65 V vs. RHE and E°'(CuII/CuI)=0.45 V for (Cu,Fe)−N−CNT, and E°'(FeIII/FeII)=0.65 V for Fe−N−CNT. These results indicate that bimetallic doping into carbon nanotubes gives the effect on kinetic parameters but not on thermodynamic ones. In other words, there is no direct electronic interactions between the Cu and Fe active sites for (Cu,Fe)‐N‐CNT because such interactions should modulate their redox potentials. [ABSTRACT FROM AUTHOR]

AbstractEne-reductase (ER) has been widely applied for asymmetrical synthesis of chiral intermediates due to its substrate promiscuity, photoexcited reactivity, and excellent property with producing two chiral centers at a time. Natural ERs often exhibit the same stereoselectivity, and they need to be engineered for opposite configuration of chiral compounds. The hydrogenation process toward activated alkenes by ERs is composed of reductive half reaction and oxidative half reaction, which are dependent upon two cofactors NAD(P)H and flavin mononucleotide. The catalytic activity of ERs will be affected by the size of the substrate, the activating strength of the electron-withdrawing groups, redox potential of cofactors, and the loop flexibility around catalytic cavity. Currently, protein engineering to ERs has been successfully employed to enhance various catalytic properties, including photoexcited asymmetric synthesis. This review summarizes the approaches to reverse the stereoselectivity and enhance catalytic activity of ERs and new applications of the engineered ERs in photobiocatalytic asymmetric synthesis, besides the discussion with the existing molecular mechanisms of mutants regarding the improved catalytic performance. [ABSTRACT FROM AUTHOR]

Among multivalent redox flow batteries, the Zn‐based redox flow battery (RFB) has the advantages of high energy density, nontoxicity, and low cost. However, the severe dendrite issue hinders its deployment. Therefore, the Sn‐based RFB is reported as a prospective alternative, particularly in alkaline systems, due to its lower redox potential and four electrons transfer in redox reactions. However, the continuous growth of Sn during charge forms large Sn bulk, which increases the risk of “dead Sn” formation. By combining experiments and theoretical calculations, urea is proposed as an electrolyte additive to regulate Sn deposition on graphite felt. This is achieved through the enhanced adsorption and robust reaction of Sn(OH)62− with graphite felt. Consequently, a more uniform morphology ensues, reducing “dead Sn” formation and thus improving the average discharge voltage and areal capacity. Moreover, the Columbic efficiency becomes more stable, extending the cycle life to over 420 h (>200 cycles) without deep discharge during cycling. This study demonstrates the role of urea in achieving high‐performance Sn‐I flow battery with long cycle life, paving the way for further development of metal‐based hybrid RFBs. [ABSTRACT FROM AUTHOR]

In alkaline water electrolysis, gas bubble coverage of the electrode surface is directly linked with an increase in cell potential. Ultrasonic field presence in water electrolysis has been proven effective in removing gas bubbles from the electrode and enhancing mass transfer and bubble removal. Most studies regarding water electrolysis under sonification focused on low-concentration NaOH electrolyte solutions so there is a lack of information regarding operating conditions similar to commercial solutions. This work focused on an experimental evaluation of the effect of an ultrasonic field with a 40 kHz frequency on water electrolysis using a lab-scale electrolyser with three different KOH solutions varying in concentration (15, 25, 35% (w/w)) at 30, 40, 50, 60 °C. A reduction in cell potential was registered across all test conditions and it was maximum for 15 and 25% KOH solutions at 30 °C with 52 and 34 mV, respectively, and decreased with an increase in temperature. For a 35% KOH solution, the cell potential reduction stayed constant across all temperatures (16–19 mV). This difference was thought to be caused by the ultrasonic frequency and power and therefore required further testing. To further investigate the effect of gas bubble accumulation on the electrode surface, measurements of hydrogen bubbles' critical diameter were taken. It was found that a higher electrolyte concentration results in a lower critical diameter (0.404, 0.356, and 0.293 mm with a 15, 25, and 35% KOH, respectively) assumed to be a consequence of higher viscosity and gas formation rate at higher concentrations. • Effect of ultrasonic field is studied in water alkaline electrolysis. • Three KOH solutions varying in concentration (15, 25, 35% (w/w)) at 30, 40, 50, 60 °C were tested. • A reduction in overpotential was registered across all test conditions. • Overpotential was observed to decrease with increasing temperatures. • Ultrasonic field is effective removing gas bubbles from the electrode and enhancing mass transfer and bubble removal. [ABSTRACT FROM AUTHOR]

Alloys of platinum with alkaline earth metals promise to be active and highly stable for fuel cell applications, yet their synthesis in nanoparticles remains a challenge due to their high negative reduction potentials. Herein, we report a strategy that overcomes this challenge by preparing platinum-magnesium (PtMg) alloy nanoparticles in the solution phase. The PtMg nanoparticles exhibit a distinctive structure with a structurally ordered intermetallic core and a Pt-rich shell. The PtMg/C as a cathode catalyst in a hydrogen-oxygen fuel cell exhibits a mass activity of 0.50 A mgPt−1 at 0.9 V with a marginal decrease to 0.48 A mgPt−1 after 30,000 cycles, exceeding the US Department of Energy 2025 beginning-of-life and end-of-life mass activity targets, respectively. Theoretical studies show that the activity stems from a combination of ligand and strain effects between the intermetallic core and the Pt-rich shell, while the stability originates from the high vacancy formation energy of Mg in the alloy. Fuel cells are promising for various applications but need durable electrocatalysts. Here, the authors present a solution-phase derived Pt-Mg alloy endowed with a Pt-rich shell and an intermetallic core, showing high durability and activity. [ABSTRACT FROM AUTHOR]

The photochemistry of Fe(III)-Iminodiacetic acid complex (Fe(III)-IDA) was studied under UVA and UV/Vis irradiation. The synthesis was realised via molar ratio method modified by reaction of IDA as ligand with Fe(III) as metal. The interaction of Fe(III) with IDA was characterised using Fourier-transform infrared (FTIR) and spectroscopy UV–visible. The results confirmed the stability of the complex at pH > 5; with constant of stability (Log β = 10.02) and stoichiometry Fe(III): IDA = 1:1. In addition, the redox potential was calculated at 521 mV, which is significantly lower than E° for the Fe(III)/Fe(II) couple. The photolysis of this complex in the presence of UVA light and UV/Vis light at different pHs was carried out. This photolysis was followed by several assay Fe(II) and •OH. The results show that the Fe(III)-IDA complex present a photo-reactivities under either light source and the phenomenon is faster when the UV/Vis was used. The initial conversion rate (r0) decreased with increasing of initial pH. The formation of hydroxyl radicals via the Fenton reaction was improved at pH = 2.12 for both irradiation sources used. Reduction of total organic carbon was also studied using the total organic carbon (TOC). The feasibility of amino iron complexes to improve the Fenton process under irradiation was confirmed. Additionally, our research also evidenced the optimal conditions for the formation of hydroxyl radicals; which are the key factor in remove pharmaceuticals pollutants in aqueous media. Based on the results obtained, the Fe(III)-IDA complex could be efficiently photolysis under UV/Vis light. [ABSTRACT FROM AUTHOR]

Potentially harmful element (PHE) bioavailability is important to environmental contamination and must be checked under several soil conditions. This study aimed to assess Fe, Mn, and PHE uptake by rice (Oryza sativa) grown on flooded and non-flooded Fe tailings collected from the Doce River basin after its collapse in Brazil. After 65 days of sowing, shoots and roots were harvested to determine PHE concentrations. The mean concentrations of Mn in shoots and Fe in the roots of rice grown on the flooded tailings were 2140 mg kg−1 and 15,219 mg kg−1, respectively. Mn was extensively translocated from roots to shoots (translocation factor (TF) = 2). Conversely, Fe accumulated in roots (TF = 0.015) and caused morphological damage to this rice organ. The application of macro and micronutrients lessened Fe toxicity in the roots of rice cultivated on the flooded tailings. The flooding of tailings influenced more Fe accumulation than Mn accumulation by rice plants. The PHE Ag, As, Cd, Ni, Hg, Pb, and Sb exhibited low total concentrations (maximum of 9 mg kg−1 for Ni and a minimum of 0.2 mg kg−1 for Cd, Hg, and Sb), and it was not observed an increase in their availability under tailings flooding conditions. [ABSTRACT FROM AUTHOR]

Zinc metal has emerged as a promising candidate for high‐capacity and low‐cost anodes in aqueous zinc‐ion batteries; nevertheless, it encounters serious obstacles, including low cycling stability and poor reversibility, caused by parasitic reactions and the formation of zinc dendrites. Herein, the study proposes a novel nonprotonic dimethylacetamide (DMAC)/ZnCl2/LiCl electrolyte that enables both solvation structural modulation of [ZnClx]2‐x and the cationic electrostatic shielding effect of [Li(DMAC)]+ by controlling the concentration of LiCl. The optimal concentration of LiCl electrolyte (0.28 m), which results in the highest ratio of [ZnCl3]−, strikes a balance between low desolvation energy and a high mass transfer rate while promoting homoepitaxial deposition of Zn (002). Moreover, inert [Li(DMAC)]+ ions, which possess a lower reduction potential, preferentially adsorb onto zinc protrusions, mitigating the tip effect. Leveraging electrolyte engineering, the zinc deposition/stripping process results in impressive long‐term stability, surpassing 2,800 cycles, and the Zn||MnO2 cell also achieves a stable lifespan extending beyond 1400 cycles. The research highlights the potential of LiCl as an additive in the modulation of water‐free electrolytes. [ABSTRACT FROM AUTHOR]

During natural behavior, an action often needs to be suddenly stopped in response to an unexpected sensory input—referred to as reactive stopping. Reactive stopping has been mostly investigated in humans, which led to hypotheses about the involvement of different brain structures, in particular the hyperdirect pathway. Here, we directly investigate the contribution and interaction of two key regions of the hyperdirect pathway, the orbitofrontal cortex (OFC) and subthalamic nucleus (STN), using dual-area, multielectrode recordings in male rats performing a stop-signal task. In this task, rats have to initiate movement to a go-signal, and occasionally stop their movement to the go-signal side after a stop-signal, presented at various stop-signal delays. Both the OFC and STN show near-simultaneous field potential reductions in the beta frequency range (12–30 Hz) compared with the period preceding the go-signal and the movement period. These transient reductions (∼200 ms) only happen during reactive stopping, which is when the stop-signal was received after action initiation, and are well timed after stop-signal onset and before the estimated time of stopping. Phase synchronization analysis also showed a transient attenuation of synchronization between the OFC and STN in the beta range during reactive stopping. The present results provide the first direct quantification of local neural oscillatory activity in the OFC and STN and interareal synchronization specifically timed during reactive stopping. [ABSTRACT FROM AUTHOR]

A series of non-innocent halogen substituted Schiff base vanadium catecholates were added with different electron donating and withdrawing substituents on the catecholates to investigate the electronic effects on the properties of this class of compounds. We hypothesized that the electronic changes would be reflected in their redox properties and stabilities, which should lead to differences in their biological properties. Using UV-spectroscopy, we measured their hydrolytic stability, and using electrochemistry, we characterized their redox properties. Adding one substituent on the catecholate group on the complexes changed the redox potentials of the complexes; however, less impact on the hydrolytic stability was observed. We discovered that hydrolytic stability was crucial to the anti-proliferative effects on glioblastoma cells, and most of these compounds had effects similar to vanadates regardless of their different redox properties. Hence, we could not determine the importance of changing the electronic properties and redox potential on the anti-proliferative effects of mono-substituted catecholates. However, the studies did show that the pKa of the substituted catecholate showed a linear correlation with the redox potential of the non-innocent Schiff base vanadium complexes, which will be important in future investigations into this class of complexes. [ABSTRACT FROM AUTHOR]

With the objective of gaining insight into the modulation of the reduction potential of the Ni(II / I) couple, we have synthesized two mononuclear nickel(II) complexes, NiLen (H2Len = N,N′-bis(3-methoxysalicylidene)-1,2-diamino-2-methylpropane) and NiLpn (H2Lpn = N,N′-bis(3-methoxysalicylidene)-1,3-diamino-2,2-dimethylpropane) of two N2O4 donor ligands and recorded their cyclic voltammograms. Both the nickel complexes show reversible reduction processes for the Ni(II / I) couple in acetonitrile solution but the reduction potential of NiLpn (E1/2 = −1.883 V) is 188 mV more positive than that of NiLen (E1/2 = −2.071 V). In the presence of redox inactive metal ions (Li+, Na+, K+, Mg2+, Ca2+ and Ba2+), the reduction potentials are shifted by 49–331 mV and 99–435 mV towards positive values compared to NiLen and NiLpn, respectively. The shift increases with the decrease of the pKa of the respective aqua-complexes of the metal ion but is poorly co-linear; however, better linearity is found when the shift of the mono- and bi-positive metal ion aqua complexes is plotted separately. Spectrophotometric titrations of these two nickel complexes with the guest metal ions in acetonitrile showed a well-anchored isosbestic point in all cases, confirming the adduct formation of NiLen and NiLpn with the metal ions. Structural analysis of single crystals, [(NiLen)Li(H2O)2]·ClO4 (1), [(NiLpn)Li(H2O)]·ClO4 (2), [(NiLpn)2Na]·BF4 (3) and [(NiLpn)2Ba(H2O)(ClO4)]·ClO4 (4), also corroborates the heterometallic adduct formation. The orbital energies of the optimised heterometallic adducts from which electron transfers originated were calculated in order to explain the observed reduction process. A strong linear connection between the calculated orbital energies and the experimental E1/2 values was observed. According to MEP and 2D vector field plots, the largest shift for divalent metal ions is most likely caused by the local electric field that they impose in addition to Lewis acidity. [ABSTRACT FROM AUTHOR]

The electrochemical nitrate reduction for green ammonia production is attracting increasing attention, where the catalysts are widely investigated by controlling the compositions or structures to achieve high performance. However, their reconstructions under reduction potentials are inevitable and uncontrollable, leading to uncertain performance, and a confused understanding of the mechanism. In this work, a strategy is proposed by controlling the pre‐catalyst's reconstruction chemistry toward electrochemical nitrate reduction reaction (e‐NO3RR) with superior activity and stability. To demonstrate the idea, a pre‐catalyst is fabricated with α‐Co(OH)2 and Cu(OH)2 (α‐Co(OH)2/Cu(OH)2), which is in situ reconstructed to a tandem catalyst with Cu and β‐Co(OH)2 (Cu/β‐Co(OH)2) under working potential. Cu/β‐Co(OH)2 achieves an optimal Faraday efficiency for ammonia of 97.7% with a yield rate of 3.9 mmol h−1 cm−2 at −0.5 V, outperforming other reported metal‐hydroxide catalysts. The experimental and theoretical results demonstrate that a tandem catalytic mechanism is responsible for the exceptional performance: 1) Cu functions as the donor of nitrite; and 2) β‐Co(OH)2 serves as active sites for generating active hydrogen and reducing nitrogen‐containing groups. This work highlights that the controllable reconstruction toward improved performance can be realized, and provides an insightful understanding of the mechanism, which is helpful for developing active and stable catalysts for various catalytic applications. [ABSTRACT FROM AUTHOR]

Conjugated sulfonamides (CSAs) stand out for their propitious electroactivity and notable stability in ambient conditions, making them suitable candidates for high‐potential cathode materials in lithium‐ion batteries (LIBs). This study employs a combination of machine learning, semi‐empirical quantum mechanics, and density functional theory methods to evaluate a large library of 11 432 CSA molecules, focusing on material properties crucial for application in batteries, such as synthetic complexity, redox potential, gravimetric charge capacity, and energy density. After applying the thresholds for the synthetic complexity score at 2.62 and the redox potential at 3.25 V versus Li/Li+, we identify 50 CSA molecules that are easy to synthesize and suitable for the positive electrode in LIBs. By ranking on the basis of redox potential, 13 CSA molecules having potentials greater than 3.50 V versus Li/Li+ are identified. Through further investigations using molecular dynamics simulations on these reactant molecules and their lithiated products, a molecule is singled out for synthesis and electrochemical evaluation. This molecule, lithium (2,5‐dicyano‐1,4‐phenylene)bis((methylsulfonyl)amide)(Li2‐DCN‐PDSA), demonstrates a redox potential surpassing those previously reported within the class of CSA molecules. Moreover, the study explores the quantitative structure‐property relations of CSAs, yielding insights for the development of CSA‐based LIB cathode materials, informed by the comprehensive data assembled. [ABSTRACT FROM AUTHOR]

Determination of bar spacing of bycatch reduction devices (BRDs) should consider species composition and morphometric characteristics (particularly width) of target species krill and bycatch. This study conducted a scientific investigation of the finfish bycatch in the Antarctic krill (Euphausia superba) trawl fishery by the fishing vessel SHEN LAN in the waters surrounding the South Orkney Islands from December 24, 2022, to February 20, 2023. The results show that scientific observers sampled 676 individuals of finfish bycatch. Of these, 665 were identified to species (17 species from 8 families), while the remaining 11 specimen were juveniles of the Nototheniidae family that could not be identified to the species level. IRI (index of relative importance) calculations showed three dominant (IRI value greater than 1,000) finfish bycatch species (Champsocephalus gunnari, Pseudochaenichthys georgianus, and C. aceratus from the Channichthyidae family) and four important (IRI value between 1,000 and 100) finfish bycatch species (Electrona carlsbergi and Gymnoscopelus nicholsi fromthe Myctophidae family, Gobionotothen gibberifrons from the Nototheniidae family, and Notolepis coatsi from the Paralepididae family). Our study provides morphometric data (particularly body width) that is crucial to model the potential for bycatch reduction by use of bycatch reduction devices (BRDs) and to determine the appropriate candidate bar spacings for BRD sea trials. Predictions suggest that a 10 mm (the maximum body width of krill) bar spacing releases a significant amount of dominant and important bycatch species (93.94% of C. gunnari, 53.99% of P. georgianus, 76.25% of C. aceratus, and 100% of G. gibberifrons). Reduced fishing pressure would reduce the risks to dominant and important bycatch species to make the krill fishery sustainable. We recommend that future BRD sea trials should initially test a 10mmbar spacing. Ifmarked loss of krill is observed, wider spacings (e.g. 15 mm) must be tested. [ABSTRACT FROM AUTHOR]

Threat mapping is a necessary tool for identifying and abating direct threats to species in the ongoing extinction crisis. There are known gaps in the threat mapping literature for particular threats and geographic locations, and it remains unclear if the distribution of research effort is appropriately targeted relative to conservation need. We aimed to determine the drivers of threat mapping research effort and to quantify gaps that, if filled, could inform actions with the highest potential to reduce species' extinction risk. We used a negative binomial generalized linear model to analyze research effort as a function of threat abatement potential (quantified as the potential reduction in species extinction risk from abating threats), species richness, land area, and human pressure. The model showed that threat mapping research effort increased by 1.1 to 1.2 times per standardized unit change in threat abatement potential. However, species richness and land area were stronger predictors of research effort overall. The greatest areas of mismatch between research effort and threat abatement potential, receiving disproportionately low research effort, were related to the threats to species of agriculture, aquaculture, and biological resource use across the tropical regions of the Americas, Asia, and Madagascar. Conversely, the threat of linear infrastructure (e.g., roads and rails) across regions, the threat of biological resource use (e.g., hunting or collection) in sub‐Saharan Africa, and overall threats in North America and Europe all received disproportionately high research effort. We discuss the range of methodological and sociopolitical factors that may be behind the overall trends and specific areas of mismatch we found. We urge a stronger emphasis on targeting research effort toward those threats and geographic locations where threat abatement activities could make the greatest contribution to reducing global species extinction risk. [ABSTRACT FROM AUTHOR]

This paper addresses the growing challenges and developments in frequency control within power systems influenced by the increasing penetration of renewable energy sources. It evaluates the advancements and limitations of renewable-based control technologies and explores the critical role of diverse energy storage technologies in providing fast frequency response ancillary services. Through a comprehensive analysis of the global literature, this paper categorises energy storage solutions according to their efficacy in meeting fast frequency response demands and potential for revenue generation. It reveals significant gaps in the current research, which predominantly focuses on battery energy storage systems and microgrid applications, with insufficient attention to grid-scale storage solutions and innovative energy storage technologies. This analysis identifies a lack of detailed technical simulations and hybrid storage models for frequency control, as well as a minimal exploration of the environmental benefits, particularly in terms of carbon dioxide emission reductions, associated with deploying new energy storage technologies in ancillary service markets. The paper concludes by emphasising the urgent need for further research incorporating detailed techno-economic evaluations and the carbon dioxide reduction potential of modular, scalable energy storage technologies, which should be facilitated by advanced network simulation models and comprehensive market analysis to drive future advancements in the field. [ABSTRACT FROM AUTHOR]

Fe(III) has been proved to be a more effective oxidant than dissolved oxygen at ambient temperature, however, the role of Fe(III) in pyrite acidic pressure oxidation was rarely discussed so far. In this paper, in-situ electrochemical investigation was performed using a flow-through autoclave system in acidic pressure oxidation environment. The results illustrated that increasing Fe(III) concentrations led to raising in redox potential of the solution, and decreased passivation of pyrite caused by deposition of elemental sulfur. Reduction of Fe(III) at pyrite surface was a fast reaction with low activation energy, it was only slightly promoted by rising temperatures. While, the oxidation rate of pyrite at all investigated Fe(III) concentrations increased obviously with rising temperatures, the anodic reaction was the rate-limiting step in the overall reaction. Activation energy of pyrite oxidation decreased from 47.74 to 28.79 kJ/mol when Fe(III) concentration was increased from 0.05 to 0.50 g/L, showing that the reaction kinetics were limited by the rate of electrochemical reaction at low Fe(III) concentrations, while, it gradually turned to be diffusion control with increasing Fe(III) concentrations. [ABSTRACT FROM AUTHOR]

Chile, the world's leading copper producer, generates significant volumes of mining waters, some of which cannot be recirculated into the production process. These mining waters are characterized by elevated sulfate ( SO 4 2 − ) concentrations, requiring sustainable management strategies for potential reuse. This study aims to evaluate the rhizofiltration technique using Carpobrotus chilensis for treating mining waters with a high SO 4 2 − concentration. Initially, the mining waters exhibited a pH of 7.97 ± 0.16 and a SO 4 2 − concentration of 2,743 ± 137 mg L−1, while the control water had a pH of 7.88 ± 0.08 and a SO 4 2 − concentration of 775 ± 19.0 mg L−1. The plants were hydroponically cultivated in 40 L containers with mining waters and drinking water as a control. Over an 8-week period, the pH of the mining water decreased to 3.12 ± 0.01, and the SO 4 2 − concentration declined to 2,200 ± 110 mg L−1. Notably, the fresh weight of roots was significantly higher in plants grown in mining water (22.2 ± 6.66 g) compared to those in the control treatment (14.3 ± 4.28 g). However, an undesirable increase in the acidity was observed in the mining waters after rhizofiltration, which was attributed to hydrogen sulfate (HSO4-) and/or root exudates. Despite the unexpected increase in acidity, C. chilensis effectively reduced the concentration of SO 4 2 − in mining waters by 20%. Additionally, the C. chilensis roots accumulated 4.84 ± 1.40% of sulfur (S), a level comparable to thiophore plants. This study provides evidence that this non-aquatic plant can be used in sulfate rhizofiltration. Caprobrotus chilensis is a good candidate for sulfate rhizolfiltration in mining waters. The accumulation of sulfur by the roots of Carpobrotus chilensis reached 4.84% Mining waters with a high concentration of sulfates require control of the redox potential [ABSTRACT FROM AUTHOR]

Widespread marine microbiomes exhibit compositional and functional differentiation as a result of adaptation driven by environmental characteristics. We investigated the microbial communities in both seawater and sediments on the slope (7–9 km) and the bottom (9–11 km) of the Challenger Deep of the Mariana Trench to explore community differentiation. Both metagenome‐assembled genomes (MAGs) and 16S rRNA amplicon sequence variants (ASVs) showed that the microbial composition in the seawater was similar to that of sediment on the slope, while distinct from that of sediment in the bottom. This scenario suggested a potentially stronger community interaction between seawater and sediment on the slope, which was further confirmed by community assembly and population movement analyses. The metagenomic analysis also indicates a specific stronger potential of nitrate reduction and sulphate assimilation in the bottom seawater, while more versatile nitrogen and sulphur cycling pathways occur on the slope, reflecting functional differentiations among communities in conjunction with environmental features. This work implies that microbial community differentiation occurred in the different hadal niches, and was likely an outcome of microbial adaptation to the extreme hadal trench environment, especially the associated hydrological and geological conditions, which should be considered and measured in situ in future studies. [ABSTRACT FROM AUTHOR]

The replacement of pyridyl by pyrazinyl in ligands of polypyridyl‐based cobalt water reducing catalysts (WRC) shifts reduction potentials anodically. Together with a new, trinuclear ReI photosensitizer, these WRCs show strongly improved photocatalytic performances in turnover numbers (TONs) and maximal H2 evolution rate. Depending on the catalyst structure, up to 65 kTONs at 1 μM WRC concentration were reached. Under electrocatalytic conditions in both DMF and H2O, one of the reported WRCs displays remarkable stability, producing H2 steadily over 21 and 14 d, respectively. [ABSTRACT FROM AUTHOR]

Porphyrins were identified some years ago as a promising, easily accessible, and tunable class of organic photoredox catalysts, but a systematic study on the effect of the electronic nature and of the position of the substituents on both the ground-state and the excited-state redox potentials of these compounds is still lacking. We prepared a set of known functionalized porphyrin derivatives containing different substituents either in one of the meso positions or at a β-pyrrole carbon, and we determined their ground- and (singlet) excited-state redox potentials. We found that while the estimated singlet excited-state energies are essentially unaffected by the introduction of substituents, the redox potentials (both in the ground- and in the singlet excited-state) depend on the electron-withdrawing or electron-donating nature of the substituents. Thus, the presence of groups with electron-withdrawing resonance effects results in an enhancement of the reduction facility of the photocatalyst, both in the ground and in the excited state. We next prepared a second set of four previously unknown meso-substituted porphyrins, having a benzoyl group at different positions. The reduction facility of the porphyrin increases with the proximity of the substituent to the porphine core, reaching a maximum when the benzoyl substituent is introduced at a meso position. [ABSTRACT FROM AUTHOR]