Molecular Electrostatic Potential: A New Tool to Predict the Lithiation Process of Organic Battery Materials

Conjugated Nitroxide Radical Polymer with Low Temperature Tolerance Potential for High-Performance Organic Polymer Cathode

Low-temperature operation poses a significant challenge for current commercial rechargeable lithium-ion batteries (LIBs). Organic polymer electrode materials, exhibiting a nonintercalation redox mechanism, offer a viable solution to mitigate the decline in electrochemical performance at low temperatures in LIBs. Herein, a radical polymer P(DATPAPO-TPA) with a conjugated nitrogen-rich triphenylamine derivative as the backbone and high-density nitroxide pendants has been synthesized. Due to the large interstitial spaces between adjacent structural units and polymer chains, resulting from the significant torsion angle between the benzene rings in the P(DATPAPO-TPA) skeleton, ions could effectively transport. This structural feature demonstrated a notable discharge capacity of 143.3 mA h·g-1 and a high charge-discharge plateau at ∼3.75 V vs Li+/Li, outperforming most reported radical polymer cathode materials. In addition, its capacity retention could reach 83.1% after 2000 cycles at an ultrahigh current density of 50 C, showing excellent rate capability and promising cyclability. Also notable was P(DATPAPO-TPA)'s favorable low-temperature performance that maintains a high discharge capacity of 139.2 mA h·g-1 at 0 °C. The synthesized P(DATPAPO-TPA) is a tangible illustration of a viable design strategy for low-temperature electrode materials, thereby contributing to broadening applications for radical polymer electrode materials.

Ferrocene Appended Porphyrin-Based Bipolar Electrode Material for High-Performance Energy Storage

The versatile properties of bipolar organic electrode materials have attracted considerable attention in the field of electrochemical energy storage (EES). However, their practical application is hindered by their inherent limitations including low intrinsic electrical conductivity, low specific capacity, and high solubility. Herein, a bipolar organic molecule combining both porphyrin and ferrocene moieties (CuDEFcP) [5,15-bis(ethynyl)-10,20-di ferrocenyl porphinato]copper(II)) has been developed. It is proposed as a new organic electrode material with multifunctional application for rechargeable organic lithium-based batteries (ROLBs) and dual-ion organic symmetric batteries (SDIBs). Superior performance was delivered as cathode material in lithium based dual-ion batteries (LDIBs), with a high initial discharge capacity of 300 mAh. g-1 at 0.2 A. g-1 and a reversible capacity of 58 mAh. g-1 after 5000 cycles at 1 A. g-1. However, employing it as an anode material in lithium-ion batteries (LIBs), a reversible capacity of 295 mAh. g-1 at 0.2 A. g-1 was delivered. In SDIBs, in which CuDEFcP is used as both anode and cathode, an average discharge voltage of 2.4 V and an energy density of 261 Wh.kg-1 were achieved.

Highly Conductive Imidazolate Covalent Organic Frameworks with Ether Chains as Solid Electrolytes for Lithium Metal Batteries

Poly(ethylene oxide) (PEO)-based electrolytes are often used for Li+ conduction as they can dissociate the Li salts efficiently. However, high entanglement of the chains and lack of pathways for rapid ion diffusion limit their applications in advanced batteries. Recent developments in ionic covalent organic frameworks (iCOFs) showed that their highly ordered structures provide efficient pathways for Li+ transport, solving the limitations of traditional PEO-based electrolytes. Here, we present imidazolate COFs, PI-TMEFB-COFs, having methoxyethoxy chains, synthesized by Debus-Radziszewski multicomponent reactions and their ionized form, Li+@PI-TMEFB-COFs, showing a high Li+ conductivity of 8.81 mS cm-1 and a transference number of 0.974. The mechanism for such excellent electrochemical properties is that methoxyethoxy chains dissociate LiClO4, making free Li+, then those Li+ are transported through the imidazolate COFs' pores. The synthesized Li+@PI-TMEFB-COFs formed a stable interface with Li metal. Thus, employing Li+@PI-TMEFB-COFs as the solid electrolyte to assemble LiFePO4 batteries showed an initial discharge capacity of 119.2 mAh g-1 at 0.5 C, and 82.0 % capacity and 99.9 % Coulombic efficiency were maintained after 400 cycles. These results show that iCOFs with ether chains synthesized via multicomponent reactions can create a new chapter for making solid electrolytes for advanced rechargeable batteries.

An Organic Molecular Cathode Composed of Naphthoquinones Bridged by Organodisulfide for Rechargeable Lithium Battery

Organic electrodes that embrace multiple electron transfer and efficient redox reactions are desirable for green energy storage batteries. Here, a novel organic electrode material is synthesized, i.e., 2, 2'-((disulfanediylbis (4, 1-phenylene)) bis(azanediyl)) bis (naphthalene-1, 4-dione) (MNQ), through a simple click reaction between common carbonyl and organosulfur compounds and demonstrate its application potential as a high-performance cathode material in rechargeable lithium batteries. MNQ exhibits the aggregation effect of redox-active functional groups, the advantage of fast reaction kinetics from molecular structure evolution, and the decreased solubility in aprotic electrolytes resulting from intermolecular interactions. As expected, the MNQ electrode exhibits a high initial discharge capacity of 281.2 mA h g-1 at 0.5 C, equivalent to 97.9% of its theoretical capacity, and sustains stable long-term cycling performance of over 1000 cycles at 1 C. This work adds a new member to the family of organic electrode materials, providing performance-efficient organic molecules for the design of rechargeable battery systems, which will undoubtedly spark great interest in their applications.

Spatial Structure Design of Thioether-Linked Naphthoquinone Cathodes for High-Performance Aqueous Zinc-Organic Batteries

Organic electrode materials (OEMs) have gathered extensive attention for aqueous zinc-ion batteries (AZIBs) due to their structural diversity and molecular designability. However, the reported research mainly focuses on the design of the planar configuration of OEMs and does not take into account the important influence of the spatial structure on the electrochemical properties, which seriously hamper the further performance liberation of OEMs. Herein, this work has designed a series of thioether-linked naphthoquinone-derived isomers with tunable spatial structures and applied them as the cathodes in AZIBs. The incomplete conjugated structure of the elaborately engineered isomers can guarantee the independence of the redox reaction of active groups, which contributes to the full utilization of active sites and high redox reversibility. In addition, the position isomerization of naphthoquinones on the benzene rings changes the zincophilic activity and redox kinetics of the isomers, signifying the importance of spatial structure on the electrochemical performance. As a result, the 2,2'-(1,4-phenylenedithio) bis(1,4-naphthoquinone) (p-PNQ) with the smallest steric hindrance and the most independent redox of active sites exhibits a high specific capacity (279 mAh g-1 ), an outstanding rate capability (167 mAh g-1 at 100 A g-1 ), and a long-term cycling lifetime (over 2800 h at 0.05 A g-1 ).

Rational Molecular Design of Redox-Active Carbonyl-Bridged Heterotriangulenes for High-Performance Lithium-Ion Batteries

Carbonyl aromatic compounds are promising cathode candidates for lithium-ion batteries (LIBs) because of their low weight and absence of cobalt and other metals, but they face constraints of limited redox-potential and low stability compared to traditional inorganic cathode materials. Herein, by means of first-principles calculations, a significant improvement of the electrochemical performance for carbonyl-bridged heterotriangulenes (CBHTs) is reported by introducing pyridinic N in their skeletons. Different center atoms (B, N, and P) and different types of functionalization with nitrogen effectively regulate the redox activity, conductivity, and solubility of CBHTs by influencing their electron affinity, energy levels of frontier orbitals and molecular polarity. By incorporating pyridinic N adjacent to the carbonyl groups, the electrochemical performance of N-functionalized CBHTs is significantly improved. Foremost, the estimated energy density reaches 1524 Wh kg-1 for carbonyl-bridged tri (3,5-pyrimidyl) borane, 50% higher than in the inorganic reference material LiCoO2 , rendering N-functionalized CBHTs promising organic cathode materials for LIBs. The investigation reveals the underlying structure-performance relationship of conjugated carbonyl compounds and sheds new lights for the rational design of redox-active organic molecules for high-performance lithium ion batteries (LIBs).

Molecular level investigation of interactions between pharmaceuticals and β-cyclodextrin (β-CD) functionalized adsorption sites for removal of pharmaceutical contaminants from water

This study describes a novel application of the use of molecular modeling tools for investigating the adsorption of organic micropollutants (OMPs) from water by nanocomposites. The partitioning of pharmaceuticals onto β-Cyclodextrin (β-CD) functionalized adsorbents was investigated at the molecular level to explore the atomistic interactions of pharmaceutical contaminants in water systems with β-CD and to provide insight into possible approaches for removal of pharmaceuticals from water. Molecular electrostatic surface potential mapping of β-CD derivatives was employed to examine the impact of substitution degree of β-CD and type of grafting agent on host-guest complexation. The stability of the complexes of selected pharmaceuticals and β-CD derivatives were assessed via molecular dynamics simulations to evaluate competitive adsorption between organic micropollutants (OMPs) and between OMPs and fulvic acid, a representative natural organic material (NOM) component found in water systems. Molecular electrostatic surface potential maps showed that grafting agents with aromatic and amine functional groups were found to provide attractive interactions for negatively charged OMPs. In addition, optimization of substitution degree of β-CD is necessary to enhance adsorption of target OMPs. Furthermore, it was found that aromatic ring bearing grafting agents can provide additional electrostatic attractions by π-π interactions with the aromatic ring of the OMPs. The impact of common water quality characteristics on adsorption was assessed and it was revealed that the effect of pH and calcium on adsorption depends on the ionizable functional groups present on the grafting agent. Molecular dynamics simulations showed that adsorption of target OMPs does not solely depend on hydrophobicity but is affected by electrostatic interactions. The simulations revealed that fulvic acid which is commonly present in environmental waters can be a competitor with ibuprofen for the β-CD cavity. Ultimately, this study showed that molecular level simulation can be effectively employed to investigate adsorption of OMPs by β-CD functionalized adsorbents and could be employed to enhance their design and subsequent environmental applications.

Benzopyrone-mediated quinolones as potential multitargeting antibacterial agents

A new type of benzopyrone-mediated quinolones (BMQs) was rationally designed and efficiently synthesized as novel potential antibacterial molecules to overcome the global increasingly serious drug resistance. Some synthesized BMQs effectively suppressed the growth of the tested strains, outperforming clinical drugs. Notably, ethylidene-derived BMQ 17a exhibited superior antibacterial potential with low MICs of 0.5-2 μg/mL to clinical drugs norfloxacin, it not only displayed rapid bactericidal performance and inhibited bacterial biofilm formation, but also showed low toxicity toward human red blood cells and normal MDA-kb2 cells. Mechanistic investigation demonstrated that BMQ 17a could effectually induce bacterial metabolic disorders and promote the enhancement of reactive oxygen species to disrupt the bacterial antioxidant defense system. It was found that the active molecule BMQ 17a could not only form supramolecular complex with lactate dehydrogenase, which disturbed the biological functions, but also effectively embed into calf thymus DNA, thus affecting the normal function of DNA and achieving cell death. This work would provide an insight into developing new molecules to reduce drug resistance and expand antibacterial spectrum.

4-Electron redox enabled by a perylene diimide containing side-chain amines for efficient organic cathode development

A perylene diimide containing side-chain amines (PDIN) was studied as an organic cathode for application in lithium batteries, showing a high capacity of 174 mA h g-1. The chemical structures, experimental results, and calculation analyses verify that PDIN performed a 4-electron redox reaction jointly involving its CO and side-chain amine groups. This study promotes the development of organic cathodes with multi-electron redox reactions.

A Redox-Active Covalent Organic Framework with Highly Accessible Aniline-Fused Quinonoid Units Affords Efficient Proton Charge Storage

Owing to their intrinsic safety and sustainability, aqueous proton batteries have emerged as promising energy devices. Nevertheless, the corrosion or dissolution of electrode materials in acidic electrolytes must be addressed before practical applications. In this study, a cathode material based on a redox-active 2D covalent organic framework (TPAD-COF) with aniline-fused quinonoid units featuring inherently regular open porous channels and excellent stability is developed. The TPAD-COF cathode delivers a high capacity of 126 mAh g-1 at 0.2 A g-1 , paired with long-term cycling stability with capacity retention of 84% after 5000 cycles at 2 A g-1 . Comprehensive ex situ spectroscopy studies correlated with density functional theory (DFT) calculations reveal that both the -NH- and C=O groups of the aniline-fused quinonoid units exhibit prominent redox activity of six electrons during the charge/discharge processes. Furthermore, the assembled punch battery consisting of a TPAD-COF//anthraquinone (AQ) all-organic system delivers a discharge capacity of 115 mAh g-1 at 0.5 A g-1 after 130 cycles, implying the potential application of the TPAD-COF cathode in aqueous proton batteries. This study provides a new perspective on the design of electrode materials for aqueous proton batteries with long-term cycling performance and high capacity.

Regulating the Lithium Ions' Local Coordination Environment through Designing a COF with Single Atomic Co Site to Achieve Dendrite-Free Lithium-Metal Batteries

The detrimental growth of lithium dendrites and unstable solid electrolyte interphase (SEI) inhibit the practical application of lithium-metal batteries. Herein, atomically dispersed cobalt coordinate conjugated bipyridine-rich covalent organic framework (sp2 c-COF) is explored as an artificial SEI on the surface of the Li-metal anode to resolve these issues. The single Co atoms confined in the structure of COF enhance the number of active sites and promote electron transfer to the COF. The synergistic effects of the Co─N coordination and strong electron-withdrawing cyano-group can adsorb the electron from the donor (Co) at a maximum and create an electron-rich environment, hence further regulating the Li+ local coordination environment and achieving uniform Li-nucleation behavior. Furthermore, in situ technology and density functional theory calculations reveal the mechanism of the sp2 c-COF-Co inducing Li uniform deposition and promoting Li+ rapid migration. Based on these advantages, the sp2 c-COF-Co modified Li anode exhibits a low Li-nucleation barrier of 8 mV, and excellent cycling stability of 6000 h.

Exploring the mechanism of solubilization and release of isoliquiritigenin in deep eutectic solvents

Isoliquiritigenin (ISL) is a natural medicinal product with extensive pharmacological activities. However, its low solubility limits its application. Therefore, this study aimed to explore the solubilization and release mechanism of the ISL using deep eutectic solvents (DESs). The choline chloride (ChCl) and oxalic acid (OA)/malic acid (MA)/gallic acid (GA) were used to synthesize ChCl-OA/MA/GA DESs, and the solubility of ISL in these DESs was studied to explore the solubilization mechanism of ISL. The thermodynamic properties of DESs were characterized using differential scanning calorimetry (DSC). The molecular interactions in DESs were studied using spectroscopy and molecular dynamics (MD) simulations. The relative density of DESs was measured using a pycnometric method, its accuracy was validated by comparing it with the MD simulation. The release of ISL from ChCl-OA/MA/GA eutectogels was studied using Carbomer 940 as the thickener, and the release mechanism of ISL in the eutectogels was explored by the drug release kinetic model. The solubility study found that the solubility of ISL in ChCl-OA/MA/GA DESs is 30073, 5055, and 68,103 times higher than that in an aqueous solution. In addition, further studies using MD simulations revealed that enhancing the interactions between ISL and solvent molecules can improve the solubility of ISL in DESs. In vitro release studies showed that the release of ISL in ChCl-OA/MA/GA eutectogels followed a first-order release model, with correlation coefficients of 0.9812, 0.9916, and 0.9961, respectively. In conclusion, the study of the solubilization and release mechanism of ISL in DESs provides new ideas and methods for the study of poorly soluble drugs, which is expected to improve the efficacy and clinical application value of drugs.

Ni2+ and Cu2+ complexes of N-(2,6-dichlorophenyl)-N-mesityl formamidine dithiocarbamate structural and functional properties as CYP3A4 potential substrates

Metal compounds continued to attract diverse applications due to their malleability in several capacities. In this study, we present our findings on the crystal structures and functional properties of Ni2+ and Cu2+ complexes of N'-(2,6-dichlorophenyl)-N-mesitylformamidine dithiocarbamate (L) comprising [Ni-(L)2] (1) and [Cu-(L)2] (2) with a four-coordinate metal center. We established the two complex structures through 1H and 13C nuclear magnetic resonance (NMR), elemental, and single-crystal X-ray analysis. The analyses showed that the two complexes are isomorphous, having P21/c as a space group and a unit-cell similarity index (π) of 0.002. The two complexes conform to a distorted square planar geometry around the metal centers. The calculated and experimental data, including bond lengths, angles, and NMR values, are similar. Hirshfeld surface analysis revealed the variational contribution of the different types of intermolecular contacts driven by the crystal lattice of the two solvated complexes. Our knowledge of the potential biological implication of these structures enabled us to probe the compounds as prospective CYP3A4 inhibitors. This approach mimics current trends in pharmaceutical design and biomedicine by incorporating potentially active molecules into various media to predict their biological efficacies. The simulations show appreciable binding of compounds 1 and 2 to CYP3A4 with average interaction energies of -97 and -87 kcal/mol, respectively. The protein attains at least five conformational states in the three studied models using a Gaussian Mixture Model-based clustering and free energy prediction. Electric field analysis shows the crucial residues to substrate binding at the active site, enabling CYP3A4 structure to function prediction. The predicted inhibition with these Ni2+ and Cu2+ complexes indicates that CYP3A4 overexpression in a diseased state like cancer would reduce, thereby increasing the chemotherapeutic compounds' shelf-lives for adsorption. This multidimensional study addresses various aspects of molecular metal electronics, including their application as substrate-mimicking inhibitors. The outcome would enable further research on bio-metal compounds of critical potential.

A Sulfur Heterocyclic Quinone Cathode Towards High-Rate and Long-Cycle Aqueous Zn-Organic Batteries

Organic materials have attracted much attention in aqueous zinc-ion batteries (AZIBs) due to their sustainability and structure-designable, but their further development is hindered by the high solubility, poor conductivity, and low utilization of active groups, resulting in poor cycling stability, terrible rate capability, and low capacity. In order to solve these three major obstacles, a novel organic host, benzo[b]naphtho[2',3':5,6][1,4]dithiino[2,3-i]thianthrene-5,7,9,14,16,18-hexone (BNDTH), with abundant electroactive groups and stable extended π-conjugated structure is synthesized and composited with reduced graphene oxide (RGO) through a solvent exchange composition method to act as the cathode material for AZIBs. The well-designed BNDTH/RGO composite exhibits a high capacity of 296 mAh g^-1 (nearly a full utilization of the active groups), superior rate capability of 120 mAh g^-1 , and a long lifetime of 58 000 cycles with a capacity retention of 65% at 10 A g^-1 . Such excellent performance can be attributed to the ingenious structural design of the active molecule, as well as the unique solvent exchange composition strategy that enables effective dispersion of excess charge on the active molecule during discharge/charge process. This work provides important insights for the rational design of organic cathode materials and has significant guidance for realizing ideal high performance in AZIBs.

Fe Powder Catalytically Synthesized C3N3 toward High-Performance Anode Materials of Lithium-Ion Batteries

Recently, carbon nitrides and their carbon-based derivatives have been widely studied as anode materials of lithium-ion batteries due to their graphite-like structure and abundant nitrogen active sites. In this paper, a layered carbon nitride material C₃N₃ consisting of triazine rings with an ultrahigh theoretical specific capacity was designed and synthesized by an innovative method based on Fe powder-catalyzed carbon-carbon coupling polymerization of cyanuric chloride at 260 °C, with reference to the Ullmann reaction. The structural characterizations indicated that the as-synthesized material had a C/N ratio close to 1:1 and a layered structure and only contained one type of nitrogen, suggesting the successful synthesis of C₃N₃. When used as a lithium-ion battery anode, the C₃N₃ material showed a high reversible specific capacity up to 842.39 mAh g^-1 at 0.1 A g^-1, good rate capability, and excellent cycling stability attributed to abundant pyridine nitrogen active sites, large specific surface area, and good structure stability. Ex situ XPS results indicated that Li⁺ storage relies on the reversible transformation of -C=N- and -C-N- groups as well as the formation of bridge-connected -C=C- bonds. To further optimize the performance, the reaction temperature was further increased to synthesize a series of C₃N₃ derivatives for the enhanced specific surface area and conductivity. The resulting derivative prepared at 550 °C showed the best electrochemical performance, with an initial specific capacity close to 900 mAh g^-1 at 0.1 A g^-1 and good cycling stability (94.3% capacity retention after 500 cycles at 1 A g^-1). This work will undoubtedly inspire the further study of high-capacity carbon nitride-based electrode materials for energy storage.

Computational Approaches for Organic Semiconductors: From Chemical and Physical Understanding to Predicting New Materials

While a complete understanding of organic semiconductor (OSC) design principles remains elusive, computational methods─ranging from techniques based in classical and quantum mechanics to more recent data-enabled models─can complement experimental observations and provide deep physicochemical insights into OSC structure-processing-property relationships, offering new capabilities for in silico OSC discovery and design. In this Review, we trace the evolution of these computational methods and their application to OSCs, beginning with early quantum-chemical methods to investigate resonance in benzene and building to recent machine-learning (ML) techniques and their application to ever more sophisticated OSC scientific and engineering challenges. Along the way, we highlight the limitations of the methods and how sophisticated physical and mathematical frameworks have been created to overcome those limitations. We illustrate applications of these methods to a range of specific challenges in OSCs derived from π-conjugated polymers and molecules, including predicting charge-carrier transport, modeling chain conformations and bulk morphology, estimating thermomechanical properties, and describing phonons and thermal transport, to name a few. Through these examples, we demonstrate how advances in computational methods accelerate the deployment of OSCsin wide-ranging technologies, such as organic photovoltaics (OPVs), organic light-emitting diodes (OLEDs), organic thermoelectrics, organic batteries, and organic (bio)sensors. We conclude by providing an outlook for the future development of computational techniques to discover and assess the properties of high-performing OSCs with greater accuracy.

Charge-Shifted Weak Noncovalent Interactions in the Atmospherically Important OCS Microhydrates

Stratospheric aerosol, mainly comprising microhydrated carbonyl sulfide (OCS), is among the primary drivers of climate change. In this study, we investigate the effect of microhydration on the structure, energetics, and vibrational properties of the neutral OCS molecule using ab initio calculation, molecular electrostatic potential (MESP), topological analyses of electron density, and natural bond orbital (NBO) analyses. The complexation energy increases with the cluster size, and the first solvation shell of OCS consists of four water molecules that interact with the OCS moiety preferentially through S_OCS···O_W, O_OCS···O_W, and C_OCS···O_W type of weak noncovalent interaction instead of the typical O_OCS···H-O_W and S_OCS···H-O_W H-bonds. These noncovalent interactions originate due to the electron shift from the water oxygen lone pair to the antibonding orbital of C═S [BD*(C═S)], sometimes via BD*(C═O), which substantially perturbs the bending mode of surrounding water molecules. The present study thus unravels the underlying relationship between the OCS atmospheric hydrolysis and the charge-shifted noncovalent interactions.

Molecular structure design of planar zwitterionic polymer electrode materials for all-organic symmetric batteries

All-organic symmetric lithium-ion batteries (LIBs) show promising prospects in sustainable energy storage systems, due to their environmental friendliness, structural diversity and low cost. Nevertheless, it remains a great challenge to explore suitable electrode materials and achieve excellent battery performance for all-organic symmetric LIBs. Herein, a squaraine-anthraquinone polymer (PSQ) electrode material was designed through rational molecular engineering. The well-designed extended π-conjugated system, donor-acceptor structure, abundant redox-active sites and rational manipulation of weak inter-/intramolecular interactions endow the PSQ electrode with outstanding electrochemical performance. The capacity of the PSQ cathode can be optimized to 311.5 mA h g-1 by in situ carbon-template polymerization. Impressively, PSQ-based all-organic symmetric LIBs displayed high reversible capacity (170.8 mA h g-1 at 50 mA g-1), excellent rate performance (64.9% capacity retention at 4000 mA g-1 vs. 50 mA g-1), ultralong cycle life up to 30 000 cycles at 2000 mA g-1 and 97% capacity retention after 2500 cycles at 500 mA g-1, which is one of the best comprehensive battery performances among the all-organic LIBs reported thus far.

Combined experimental and TD-DFT/DMOl3 investigations, optical properties, and photoluminescence behavior of a thiazolopyrimidine derivative

We present here the FT-IR, DFT computation, XRD, optical, and photophysical characterization of a heterocyclic compound with thienopyrimidine and pyran moieties. TD-DFT/DMOl³ and TD-DFT/CASTEP computations were used to study the geometry of isolated and dimer molecules and their optical behavior. The indirect (3.93 eV) and direct (3.29 eV) optical energy bandgaps, HOMO-LUMO energy gap (3.02 eV), and wavelength of maximum absorption (353 nm) were determined in the gas phase with M062X/6-31+G (d, p). A thin film of the studied molecule was studied using XRD, FT-IR, and UV-Vis spectroscopy. The average crystallite size was found as 74.95 nm. Also, the photoluminescence spectroscopy revealed that the compound exhibited different emission bands at the visible range with different intensities depending on the degree of molecular aggregation. For instance, solutions with different concentrations emitted blue, cyan, and green light. On the other hand, the solid-state material produced a dual emission with comparable intensities at λ_max = 455, 505, and 621 nm to cover the entire visible range and produce white emission from a single material with CIE coordinates of (0.34, 0.32) that are very similar to the ideal pure white light. Consequently, these findings could lead to the development of more attractive new luminous materials.

Discovery of Natural Rosin Derivatives Containing Oxime Ester Moieties as Potential Antifungal Agents to Control Tomato Gray Mold Caused by Botrytis cinerea

Inspired by the application of natural products against pathogenic fungi, two series of dehydroabietyl oxime ester derivatives were synthesized using rosin as a raw material. Based on the evaluation and screening of in vitro antifungal activities against Botrytis cinerea (B. cinerea), Sclerotinia sclerotiorum, Valsa mali, Rhizoctonia solani, Fusarium oxysporum, and Alternaria alternata, compound 4f exhibited the best antifungal activity against B. cinerea, and its EC₅₀ was 0.798 mg/L, which was lower than that of the positive control trifloxystrobin (1.112 mg/L). The in vivo antifungal activity results showed that 4f had satisfactory protective and curative effects on tomato. Physiological and biochemical studies showed that the action mechanism of compound 4f against B. cinerea is to change the morphology and the ultrastructure of the mycelium, increase the permeability of the cell membrane, and cause nucleus and mitochondrial dysfunction, thus leading to apoptosis. In addition, qualitative and quantitative structure-activity relationship studies showed that the inductive and conjugative interactions between compound 4f and the target receptor form an electron transfer process, thereby achieving an antifungal effect. These results indicated that compound 4f, which was derived from the natural product rosin, is a novel potential fungicidal candidate against B. cinerea.

Removal of oxytetracycline promoted by manganese-doped biochar based on density functional theory calculations: Comprehensive evaluation of the effect of transition metal doping

The regulation of surface electrons by non-metal doping of biochar (BC) is environmentally and ecologically significant. However, systematic studies on the regulation of surface electrons by transition metal doping are lacking. The present study is based on the observation that the removal efficiency of oxytetracycline (OTC) by Mn-doped BC is eight times higher than that of undoped BC in 20 min. The effects of Mn doping on the crystal phase formation, persistent free radicals (PFRs), electron density, molecular orbitals, and nucleophilic active sites of BC are investigated, and the intermediate products of OTC are evaluated. Mn doping enhances the signal for sp²-hybridised carbon-carbon double bond, forms more delocalised π-bonds, and promotes the formation of free radicals centred on the carbon atoms. The specific surface area of BC increases, and manganese oxide is formed on the its surface. Density functional theory calculations show that Mn doping accelerates the electron transfer of BC, provides additional electrons for the BC system, and makes this system more ionised. OTC molecules preferentially attack the nucleophilic reaction sites near Mn atoms based on molecular electrostatic potential measurements. Therefore, this study provides new insights into the surface electronic structures regulated by transition metal elements.

Quantitative analysis of molecular surface: systematic application in the sodiation mechanism of a benzoquinone-based pillared compound as a cathode

Quantitative analysis of molecular surface as a novel method for DFT studies of P5Q cathodes, which can simulate reasonable sodiation processes and predict accurate theoretical redox voltages.

A Symmetric All-Organic Proton Battery in Mild Electrolyte

All-organic proton batteries are attracting extensive attention due to their sustainability merits and excellent rate capability. Generally, strong acids (e.g. H₂ SO₄ ) have to be employed as the electrolytes to provide H⁺ for all-organic proton batteries due to the high H⁺ intercalation energy barrier. Until now, the design of all-organic proton batteries in mild electrolytes is still a challenge. Herein, a poly(2,9-dihydroquinoxalino[2,3-b]phenazine) (PO) molecule was designed and synthesized, where the adjacent C=N groups show two different chemical environments, resulting in two-step redox reactions. Moreover, the two reactions possess considerable voltage difference because of the large LUMO energy gap between PO and its reduction product. More impressively, the C=N groups endow the π-conjugated PO molecule with H⁺ uptake/removal in the ZnSO₄ electrolyte. As a result, a symmetric all-organic proton battery is achieved in a mild electrolyte for the first time, which exhibits enhanced electrochemical performance and also broadens the chemistry of proton-based batteries.

The Molecular Mechanism of the Formation of Four-Membered Cyclic Nitronates and Their Retro (3 + 2) Cycloaddition: A DFT Mechanistic Study

In the present work, the formation of the four-membered cyclic nitronates and the retro (3 + 2) cycloaddition (retro-32CA) reaction of the 4H-[1,2]oxazete 2-oxide were studied using the density functional theory method at the MPWB1K/6-311G(d,p) theoretical level. The electronic structure of 3-tert-butyl-4,4-dimethyl-1,2-dinitro-pent-2-ene was known through electron localization function analysis, natural population analysis, and molecular electrostatic potential analysis. The formation of 4,4-di-tert-butyl-3-nitromethyl-4H-[1,2]oxazete 2-oxide proceeds through a one-step mechanism. The mechanism of the retro-32CA leading to di-tert-butyl ketone and nitrile oxide derivative should be described as an asynchronous two-stage one-step process. The bonding evolution theory study was carried out to clarify the mechanisms of the formation of 4H-[1,2]oxazete 2-oxide and their retro-32CA.

Molecularly Compensated Pre-Metallation Strategy for Metal-Ion Batteries and Capacitors

The use of a sacrificial cathode additive as a pre-metallation method could ensure adequate metal sources for advanced energy storage devices. However, this pre-metallation technique suffers from the precise regulation of decomposition potential of additive. Herein, a molecularly compensated pre-metallation (Li/Na/K) strategy has been achieved through Kolbe electrolysis, in which the electrochemical oxidation potential of a metal carboxylate is manipulated by the bonding energy of the oxygen-metal (O-M) moiety. The electron-donating effect of the substituent and the low charge density of the cation can dramatically weaken the O-M bond strength, further bringing out the reduced potential. Thus, sodium acetate exhibits a superior pre-sodiation feature for sodium-ion battery accompanied with a large irreversible specific capacity of 301.8 mAh g^-1 , remarkably delivering 70.6 % enhanced capacity retention in comparison to the additive-free system after 100 cycles. This methodology has been extended to construct a high-performance lithium-ion battery and a lithium/sodium/potassium-ion capacitor.

An Ultralow Temperature Aqueous Battery with Proton Chemistry

Conventional aqueous batteries usually suffer from serious capacity loss under subzero conditions owing to the freeze of electrolytes. To realize the utilization of aqueous batteries in extremely cold climates, low-temperature aqueous battery systems have to be developed. Herein, an aqueous Pb-quinone battery based on p-chloranil/reduced graphene oxide (PCHL-rGO) in H₂ SO₄ electrolyte is developed. Such aqueous Pb/PCHL-rGO batteries display H⁺ insertion chemistry, which endows the batteries with fast reaction kinetics and high rate capability. In addition, the hydrogen bonds between water molecules can be significantly damaged in electrolyte by modulating the interaction between SO₄ ^2- and water molecules, lowering the freezing point of electrolyte. As a result, the Pb/PCHL-rGO batteries deliver extraordinary electrochemical performance even at -70 °C. This work will broaden the horizons of aqueous batteries and open up new opportunities to construct low-temperature aqueous batteries.

Tuning the donating strength of dye sensitizers using molecular electrostatic potential analysis

The significance of electron releasing groups at the donors of D–π–A systems for improving the donating strength and power conversion efficiency of photosensitizers.

Revealing practical specific capacity and carbonyl utilization of multi-carbonyl compounds for organic cathode materials

Organic carbonyl compounds are regarded as promising candidates for next-generation rechargeable batteries due to their low cost, environmentally benign nature, and high capacity. The carbonyl utilization is a key issue that limits the practical specific capacity of multi-carbonyl compounds. In this work, a combination of thermodynamic computation and electronic structure analysis is carried out to study the influence of carbonyl type and carbonyl number on the electrochemical performance of a series of multi-carbonyl compounds by using density functional theory (DFT) calculations. By comparing discharge profiles of six tetraone compounds with different carbonyl sites, it is demonstrated that pentacene-5,7,12,14-tetraone (PT) with para-dicarbonyl and pyrene-4,5,9,10-tetraone (PTO) with ortho-dicarbonyl undergo four-lithium transfer while the other four compounds with meta-dicarbonyl fragments show only two-lithium transfer during the discharge process. By further increasing the carbonyl number, the electrochemical performance of molecules with similar para-dicarbonyl sites to PT can not be strongly improved. Among all the studied multi-carbonyl compounds, triphenylene-2,3,6,7,10,11-hexaone (TPHA) and tribenzo[f,k,m]tetraphen-2,3,6,7,11,12,15,16-octaone (TTOA) with similar ortho-dicarbonyl sites to PTO exhibit the best electrochemical performance due to simultaneous high specific capacity and high discharge voltage. Our results offer evidence that conjugated multiple-carbonyl molecules with ortho-dicarbonyl sites are promising in developing high energy-density organic rechargeable batteries.

A boron-exposed TiB3 monolayer with a lower electrostatic-potential surface as a higher-performance anode material for Li-ion and Na-ion batteries

The lack of high-performance anode materials has become a major obstacle to the development of Li- and Na-ion batteries. Recently, 2D transition metal borides (e.g. MBenes) have attracted much attention due to their excellent stability and electrical conductivity. Unfortunately, most of the reported MBene phases typically have an intrinsic metal-rich structure with metal atoms exposed on the surface, which harmfully affect the adsorption of Li/Na atoms. Here, through crystal structure prediction combined with the first-principles density functional theory, a novel TiB3 MBene has been determined by altering the proportion of non-metallic element boron to wrap metal atoms and weaken nearest-neighbor electrostatic repulsion. Electrostatic potential analysis visually shows a surface with low potential on the TiB3 monolayer implying high adsorption capacity, and also can be used to quickly screen out the Li/Na adsorption sites. Accurate half-cell battery simulation confirmably shows that the TiB3 monolayer possesses a theoretical specific capacity of 1335.04 and 667.52 mA h g-1 for Li and Na, respectively. The TiB3 monolayer can remain metallic after adsorbing Li/Na atoms, which ensures good conductivity during battery cycling. The ultra-low barrier energy (only 38 meV for Li) and suitable open-circuit voltage indicate excellent charging and discharging capabilities. These results suggest that the TiB3 monolayer could be a promising anode material for Li- and Na-ion batteries, and provide a simple design principle for exposing non-metallic atoms on the surface.

A Self-Polymerized Nitro-Substituted Conjugated Carbonyl Compound as High-Performance Cathode for Lithium-Organic Batteries

Conjugated carbonyl compounds have received much attention as cathode materials for developing green lithium-ion batteries (LIBs). However, their high dissolution and poor electronic conductivity in organic electrolyte restrict their further application. Herein, a self-polymerized nitro-substituted conjugated carbonyl compound (2,7-dinitropyrene-4,5,9,10-tetraone, PT-2 NO₂ ) is applied as a high-performance cathode material for LIBs. PT-2 NO₂ exhibits a high reversible capacity of 153.9 mAh g^-1 at 50 mA g^-1 after 120 cycles, which is higher than that of other substituted compounds. Detailed characterization and theoretical calculations have testified that PT-2 NO₂ is transformed into an azo polymer through an irreversible reductive coupling reaction in the first discharge process, and then carbonyl and azo groups reversibly react with Li ions in subsequent cycles. In addition, this azo polymer is also synthesized and applied as the electrode material, which shows similar electrochemical performance to PT-2 NO₂ but with higher initial coulombic efficiency. Thus, this work provides a simple but effectively way to construct organic cathode materials with multiple redox sites for green and high-performance LIBs.

Carbonyl Bridge-Based p-π Conjugated Polymers as High-Performance Electrodes of Organic Lithium-Ion Batteries

Organic redox compounds have shown promising potential as electrode materials for lithium-ion batteries. Polymerization is an effective and feasible method to prevent rapid capacity decay. However, present conjugated polymers and nonconjugated polymers have their own limitations to constructing stable and high-performance electrodes. Herein, we report a novel polyimide NDI-O, which is connected by carbonyl bridges. The NDI-O is a p-π conjugated polymer that exhibits a high gravimetric energy density of 542 W h kg^-1 and an ultrahigh power density of 14,000 W kg^-1 due to its intriguing electronic properties. The combination of molecular electrostatic potential calculations and ex situ technologies reveals the lithium-ion storage mechanism during the charge and discharge processes. The orbital distribution calculations and electrochemical impedance spectroscopy tests have been shown to verify the excellent kinetic properties of NDI-O. This work expands the scope of polymers applied for LIBs and provides new methods to construct high-performance electrode materials for sustainable batteries.