Chemistry, Volume 7, Issue 4 (August 2025) – 34 articles

A new Schiff base, (E)-2-(((1,10-phenanthrolin-5-yl)imino)methyl)-4,6-di-tert-butylphenol (Fen-IHB), was designed to incorporate an intramolecular hydrogen bond (IHB) between the phenolic OH and the azomethine nitrogen with the goal of modulating its physicochemical and biological properties. Fen-IHB was synthesized by condensation of 5-amino-1,10-phenanthroline with 3,5-di-tert-butyl-2-hydroxybenzaldehyde and exhaustively characterized by HR-ESI-MS, FTIR, 1D/2D NMR (¹H, ¹³C, DEPT-45, HH-COSY, CH-COSY, D₂O exchange), and UV–Vis spectroscopy. Cyclic voltammetry in anhydrous CH₃CN revealed a single irreversible cathodic peak at −1.43 V (vs. Ag/Ag⁺), which is consistent with the intramolecular reductive coupling of the azomethine moiety. Density functional theory (DFT) calculations, including MEP mapping, Fukui functions, dual descriptor analysis, and Fukui potentials with dual descriptor potential, identified the exocyclic azomethine carbon as the principal nucleophilic site and the phenolic ring (hydroxyl oxygen and adjacent carbons) as the main electrophilic region. Noncovalent interaction (NCI) analysis further confirmed the strength and geometry of the intramolecular hydrogen bond (IHB). In vitro antimicrobial assays indicated that Fen-IHB was inactive against Gram-negative facultative anaerobes (Salmonella enterica serovar Typhimurium and Typhi, Escherichia coli) and strictly anaerobic Gram-positive species (Clostridioides difficile, Roseburia inulinivorans, Blautia coccoides), as any growth inhibition was indistinguishable from the DMSO control. Conversely, Fen-IHB displayed measurable activity against Gram-positive aerobes and aerotolerant anaerobes, including Bacillus subtilis, Streptococcus pyogenes, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus haemolyticus. Overall, these comprehensive characterization results confirm the distinctive chemical and electronic properties of Fen-IHB, underlining the crucial role of the intramolecular hydrogen bond and electronic descriptors in defining its reactivity profile and selective biological activity. Full article

This work presents new results and conclusions on nanomembrane filtration and reverse osmosis of Mavrud red wine, produced in Bulgaria. The experiments were focused on lowering the alcohol content while preserving the valuable substances in the wine. Commercially available nanomembranes were used (Alfa Laval NF99HF, Alfa Laval RO99, NADIR NP030P). Two modes of nanofiltration (concentration mode and diafiltration mode, including constant volume diafiltration and two-step diafiltration) and reverse osmosis were employed for this study. The nanofiltration membranes (Alfa Laval NF99HF, NADIR NP030P) used for wine dealcoholization showed high separation effectiveness. Several wine components were recognized as indicators to be monitored during the process: carboxylic acids (citric, tartaric, malic, succinic, acetic); monosaccharides (glucose, fructose); alcohol (ethanol). The monitoring of the named compounds was performed with an HPLC-RID system on an H-charged ion exclusion analytical column. Based on the analysis of the collected samples, it could be stated that the alcohol content in the wine was lowered from 11.8% to 4.3 vol% of ethanol, when the sequential diafiltration mode of operation is used. Content change depends on the type of molecule; for example, in most cases the citric acid is strongly retained (Rej > 90%) by the membrane, whereas the acetic acid could permeate significantly (Rej < 20%). The obtained results present valuable information about the changes in the composition of the Mavrud wine which will aid in the preservation of the chemical composition and valuable substances in the event of future full or partial dealcoholization of this wine variety. Full article

Nanofluidic memristors are an emerging class of devices that harness ion transport in confined nanoscale environments to achieve tunable resistance states, mimicking biological synaptic functions. The regulation of ion migration, accumulation, and depletion in nanofluidic channels is fundamentally governed by chemical principles, including surface charge modulation, electrostatic interactions, and ion adsorption and desorption processes. This review provides a comprehensive overview of the chemical foundations of nanofluidic memristors, including electric double layer theory, ion transport dynamics, and interfacial chemistry. Additionally, this review further explores how interfacial chemical modifications, such as functionalization with charged species, pH-responsive coatings, and ionic selectivity molecules, influence nanofluidic memristive behaviors. Representative case studies are discussed to illustrate the practical implementation of these principles in applications ranging from neuromorphic computing to biosensing and energy storage. By bridging fundamental chemical theories with real-world applications, this review aims to provide insights into the rational design of next-generation nanofluidic memristive devices. Full article

The COVID-19 pandemic has prompted the scientific community to develop new weapons against the SARS-CoV-2 spike protein. The study of its mutations is important to understand how it interacts with human receptors and how to prevent a future pandemic. In this study, four mutations of the Omega variant, along with those from the SARS-CoV-1 and MERS variants, were analyzed in complex with the angiotensin-converting enzyme 2 (ACE2) receptor. In silico studies were carried out to demonstrate that these mutations affect the interaction with the compounds under investigation. The ligands studied are heterocyclic compounds previously considered as potential inhibitors. Our results show that these compounds interact well with the spike protein and provide insights into how mutations, especially in the RBD region, can lead to perturbations in ligand–protein interactions. Full article

The reaction of thiophenylsulfides with diacetoxyiodobenzene, iodine and light produced corresponding acetoxylated products, allowing the formation of new C-O bonds from starting materials other than carbonyls in high yields. Hence, under these conditions, thiophenylsulfide underwent displacement/substitution by an acetate. ¹H-NMR studies of the reaction carried out with exclusion of each single reactant pointed at two operative pathways and to the involvement of an intermediate that was assigned as an acetoxy sulfonium (IV) species. Full article

Endophytes are important sources of bioactive secondary metabolites with therapeutic and agricultural relevance. This study reports the isolation and characterization of bioactive compounds from endophytic Fusarium solani associated with Solanum surattense. The fungal strain, selected after preliminary screening for its antimicrobial potential, was identified through morphological and molecular methods. A pure compound, 4-hydroxyphenyl 8-chlorooctanoate with a molecular mass of 270, was obtained and structurally characterized using GC–MS, FTIR, and NMR spectroscopy. Its anti-microbial potential was evaluated through molecular docking against key bacterial (Staphylococcus aureus) and fungal (Aspergillus fumigatus) targets, showing notable binding affinities with ClpP protease (−7.1 kcal/mol) and 14α-demethylase (−7.4 kcal/mol), respectively. Molecular dynamics simulations further confirmed the stability of the 5FRB-compound complex, with lower RMSD and RMSF values indicating strong structural integrity. Supporting analyses (B-factor and radius of gyration) confirmed the compactness and rigidity of the complex. These findings highlight the potential of 4-hydroxyphenyl 8-chlorooctanoate as a promising antimicrobial agent and provide a strong basis for further in vitro and in vivo validation of the purified compound as an antimicrobial candidate. Full article

The presence of sulfate anions induces the self-assembly of anion-binding bis(cyclopeptides) in which two cyclopeptide rings are connected via a rigid linker. In this way, 2:2 complexes are formed in which two anions are sandwiched between two bis(cyclopeptide) moieties. Mixed species can be formed if two bis(cyclopeptides) containing different linkers are present and the structural mismatch between the linkers can be compensated for in the self-assembled product. Sulfate complexation seems to proceed with positive cooperativity, leading primarily to the fully formed complexes. As a consequence, these bis(cyclopeptides) represent useful building blocks for the anion-mediated formation of self-assembled products with controllable structural complexity. Full article

Aluminum (Al) and zinc (Zn) are two of the most widely used metals in industry, and their excessive accumulation in the body has been linked to serious diseases like Alzheimer’s, Parkinson’s, and cancer. This highlights the need for effective ways to detect and measure them. In this study, we synthesized the fluorescent chemosensor 1, which contains a Schiff base and a 1,3,4-thiadiazole ring in its structure, and evaluated its fluorescent response in the presence of various metal ions. The chemosensor enabled the selective quantification of Al³⁺ and Zn²⁺ ions through excitations at different wavelengths, yielding differentiated fluorescent emissions. For Al³⁺, excitation at 370 nm generated a strong emission at 480 nm, whereas for Zn²⁺, excitation at 320 nm led to a new small broad emission at 560 nm. We established detection limits of 2.22 × 10⁻⁶ M for Al³⁺ and 1.62 × 10⁻⁵ M for Zn²⁺; their binding stoichiometry was found to be 1:1 for Al³⁺ and 2:1 for Zn²⁺, based on Job’s plot analysis. These results show that chemosensor 1 is a promising tool for detecting Al³⁺ and Zn²⁺. Full article

Aromaticity and antiaromaticity are concepts that are often used to explain and predict the physical and chemical properties of cyclic conjugated compounds. They are associated with 4n + 2 and 4n cyclically arranged electrons that are delocalized and mostly localized, respectively. The large number of papers devoted to these concepts, together with two recent conferences on aromaticity (Aromaticity 2018 and 2025, Mexico) that brought together experts from all over the world to discuss aromaticity and antiaromaticity and their applications testify to their importance, but also to the lack of a simple and easily understandable definition. This review highlights the most important manifestations of (anti)aromaticity by considering selected examples from the literature, chosen to provide us with a clearer picture of these two concepts. Full article

This study investigates the influence of vacancy engineering and nitrogen doping on the structural, electronic, and optical properties of T-graphene fragments (TFs) using density functional theory (DFT) and time-dependent DFT (TD-DFT). A central vacancy and five pyridinic nitrogen doping configurations are explored to modulate the optoelectronic behavior. All systems are thermodynamically stable, exhibiting tunable HOMO–LUMO gaps, orbital distributions, and charge transfer characteristics. Optical absorption spectra show redshifts and enhanced oscillator strengths in doped variants, notably v-NTF2 and v-NTF4. Nonlinear optical (NLO) analysis reveals significant enhancement in both static and frequency-dependent responses. v-NTF2 displays an exceptionally high first-order hyperpolarizability (⟨β⟩ = 1228.05 au), along with a strong electro-optic Pockels effect (β (−ω; ω, 0)) and second harmonic generation (β (−2ω; ω, ω)). Its third-order response, γ (−2ω; ω, ω, 0), also exceeds 1.2 × 10⁵ au under visible excitation. Conceptual DFT descriptors and energy decomposition analysis further supports the observed trends in reactivity, charge delocalization, and stability. These findings demonstrate that strategic nitrogen doping in vacancy-engineered TFs is a powerful route to tailor electronic excitation, optical absorption, and nonlinear susceptibility. The results offer valuable insight into the rational design of next-generation carbon-based materials for optoelectronic, photonic, and NLO device applications. Full article

The difluoromethoxy (OCF₂H) and trifluoromethoxy (OCF₃) fluorinated structural motifs are frequently seen as privileged functional groups in the field of medicinal chemistry and are regularly taken into account during the design and development processes of successful drugs. This paper presents the synthesis of four new fluorinated etheric derivatives of cannabinol (CBN) using fluorine chemistry. These reactions are straightforward in terms of operation and make use of easily obtainable reagents, making them suitable for the synthesis of various fluorinated CBN ethers with yields ranging from moderate to excellent. We successfully isolated all the products and characterized them in detail using spectroscopic methods. It is anticipated that they will increase the efficacy of drug candidates due to their ability to alter biological activities such as cellular membrane permeability and metabolic stability and improve their pharmacokinetic properties. Full article

To address the low selectivity in the electrocatalytic conversion of furfural (FFR) to furfuryl alcohol (FFA) under alkaline conditions, a Zn-based metal–organic framework (MBON-2) featuring a 3D hierarchical flower-like architecture self-assembled from nanosheets was synthesized via a simple hydrothermal method. Under optimal conditions, MBON-2 exhibited an extremely high selectivity of FFA (100%) and a high Faradaic efficiency (FE) of 93.19% at −0.2 V vs. RHE. Electrochemical impedance spectroscopy (EIS) revealed the excellent electron transfer and mass transport properties of MBON-2. In addition, in situ Fourier transform infrared (FTIR) spectroscopy studies confirmed the adsorption of FFR molecules onto the Zn and B sites of MBON-2 during the ECH of FFR, providing key insights into the hydrogenation mechanism. The numerous exposed B and Zn sites of the MBON-2, as well as its robust structural stability contributed to its outstanding catalytic performance in the electrochemical hydrogenation (ECH) of FFR. This work provides valuable guidelines for developing efficient Zn-based catalysts for the ECH of FFR. Full article

This paper serves as a comprehensive and practical resource to guide researchers in selecting suitable metals for use as photocathodes in radio-frequency (RF) and superconducting radio-frequency (SRF) electron guns. It offers an in-depth review of bulk and thin-film metals commonly employed in many applications. The investigation includes the photoemission, optical, chemical, mechanical, and physical properties of metallic materials used in photocathodes, with a particular focus on key performance parameters such as quantum efficiency, operational lifetime, chemical inertness, thermal emittance, response time, dark current, and work function. In addition to these primary attributes, this study examines essential parameters such as surface roughness, morphology, injector compatibility, manufacturing techniques, and the impact of chemical environmental factors on overall performance. The aim is to provide researchers with detailed insights to make well-informed decisions on materials and device selection. The holistic approach of this work associates, in tabular format, all photo-emissive, optical, mechanical, physical, and chemical properties of bulk and thin-film metallic photocathodes with experimental data, aspiring to provide unique tools for maximizing the effectiveness of laser cleaning treatment. Full article

A thermochromic cholesteric liquid crystal (CLC) mixture was prepared using epoxies. The structural color of the CLCN film was tuned by changing the concentration of a chiral dopant and the polymerization temperature. It was found the yellow CLCN film can be used as a sensor for the discrimination of methanol and ethanol which was proposed to be driven by the difference between the solubility parameters. Moreover, a colorful pattern was prepared based on the thermochromic property of the CLC mixture, which could be applied for decoration and as a sensor for chloroform. Full article

In this work, we report a novel mechanochemical synthesis method for the synthesis of quinoxaline derivatives—a spiral gas–solid two-phase flow approach, which enables the efficient preparation of quinoxaline compounds. Compared to conventional synthetic methods, this approach eliminates the need for heating or solvents while significantly reducing reaction time. The structures of the synthesized compounds were characterized using nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV–Vis) absorption spectroscopy, powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and high-performance liquid chromatography (HPLC). Using the synthesis of 2,3-diphenylquinoxaline (1) as a model reaction, the synthetic process was investigated with UV–Vis spectroscopy. The results demonstrate that when the total feed amount was 2 g with a carrier gas pressure of 0.8 MPa, the reaction completed within 2 min, achieving a yield of 93%. Furthermore, kinetic analysis of the reaction mechanism was performed by monitoring the UV–Vis spectra of the products at different time intervals. The results indicate that the synthesis of 1 follows the A4 kinetic model, which describes a two-dimensional diffusion-controlled product growth process following decelerated nucleation. Full article

Two pyrene derivatives, substituted at position 1 with isoxazole or NH-pyrazole, were synthesized in 85–87% yield starting from 1-acetylpyrene and via the cyclocondensation reaction of a β-enaminone intermediate with hydroxylamine or hydrazine. The photophysics of the two 5-(1-pyrenyl)-1,2-azoles were explored, revealing that only the isoxazole derivative exhibits good emission properties (ϕ_F ≥ 74%) but without solvatofluorochromism behavior. However, both probes exhibited noticeable photophysics in the aggregated state (in the presence of H₂O and/or in the solid state) and through acid–base interactions (using TFA and TBACN), leveraging the basic and acidic character of the analyzed 1,2-azoles, which was also investigated by ¹H NMR spectroscopy. Therefore, the selective incorporation of N-heteroaromatic units into the pyrene scaffold effectively modulates the photophysics and environmental sensitivity of the corresponding probes. Full article

Pyrochlore Bi_1.8Mn_0.5Ni_0.5Ta₂O_9-Δ (sp.gr. Fd-3m, a = 10.5038(9) Å) was synthesized by the solid-phase reaction method and characterized by vibrational and X-ray spectroscopy. According to scanning electron microscopy, the ceramics are characterized by a porous microstructure formed by randomly oriented oblong grains. The average crystallite size determined by X-ray diffraction is 65 nm. The charge state of transition element cations in the pyrochlore was analyzed by soft X-ray spectroscopy using synchrotron radiation. For mixed pyrochlore, a characteristic shift of Bi4f and Ta4f and Ta5p spectra to the region of lower energies by 0.25 and 0.90 eV is observed compared to the binding energy in Bi₂O₃ and Ta₂O₅ oxides. XPS Mn2p spectrum of pyrochlore has an intermediate energy position compared to the binding energy in MnO and Mn₂O₃, which indicates a mixed charge state of manganese (II, III) cations. Judging by the nature of the Ni2p spectrum of the complex oxide, nickel ions are in the charge state of +(2+ζ). The relative permittivity of the sample in a wide temperature (up to 350 °C) and frequency range (25–10⁶ Hz) does not depend on the frequency and exhibits a constant low value of 25. The minimum value of 4 × 10⁻³ dielectric loss tangent is exhibited by the sample at a frequency of 10⁶ Hz. The activation energy of conductivity is 0.7 eV. The electrical behavior of the sample is modeled by an equivalent circuit containing a Warburg diffusion element. Full article

Benzothiazole derivatives have emerged as being highly significant in drug discovery due to their versatile biological activities and structural adaptability. Incorporating nitrogen and sulfur, this fused heterocyclic scaffold exhibits wide-ranging pharmacological properties, including anticancer, antimicrobial, anti-inflammatory, antidiabetic, neuroprotective, and diagnostic applications. A diverse set of clinically approved and investigational compounds, such as flutemetamol for Alzheimer’s diagnosis, riluzole for ALS, and quizartinib for AML, illustrates the scaffold’s therapeutic potential in varied applications. These agents act via mechanisms such as enzyme inhibition, receptor modulation, and amyloid imaging, demonstrating the scaffold’s high binding affinity and target specificity. Advances in synthetic strategies and our understanding of structure–activity relationships (SARs) continue to drive the development of novel benzothiazole-based therapeutics with improved potency, selectivity, and safety profiles. We also emphasize recent in vitro and in vivo studies, including drug candidates in clinical trials, to provide a comprehensive perspective on the therapeutic potential of benzothiazole-based compounds in modern drug discovery. This review brings together recent progress to help guide the development of new benzothiazole-based compounds for future therapeutic applications. Full article

Type 2 diabetes mellitus (T2DM) demands safer and more effective therapies to control postprandial hyperglycemia. Here, we report the synthesis and in vitro evaluation of ten salicylic acid-derived Schiff base derivatives (4a–4j) as α-glucosidase inhibitors. Compounds 4e, 4g, 4i, and 4j exhibited potent enzyme inhibition, with IC₅₀ values ranging from 14.86 to 18.05 µM—substantially better than acarbose (IC₅₀ = 45.78 µM). Molecular docking and 500 ns molecular dynamics simulations revealed stable enzyme–ligand complexes driven by π–π stacking, halogen bonding, and hydrophobic interactions. Density Functional Theory (DFT) calculations and molecular electrostatic potential (MEP) maps highlighted key electronic factors, while ADMET analysis confirmed favorable drug-like properties and reduced nephrotoxicity. Structure–activity relationship (SAR) analysis emphasized the importance of halogenation and aromaticity in enhancing bioactivity. Full article

Hydrogen sulfide (H₂S), once regarded solely as a highly toxic gas, is now recognized as a crucial signaling molecule in plants, bacteria, and mammals. In humans, H₂S signaling plays a role in numerous physiological and pathological processes, including vasodilation, neuromodulation, and cytoprotection. To exploit its biological functions and therapeutic potential, a wide range of H₂S-releasing compounds, known as H₂S donors, have been developed. These donors are designed to release H₂S under physiological conditions in a controlled manner. Among them, self-reporting H₂S donors are seen as a particularly innovative class, combining therapeutic delivery with real-time fluorescence-based detection. This dual functionality enables spatiotemporal monitoring of H₂S release in biological environments, eliminating the need for additional sensors or probes that could disrupt cellular homeostasis. This review summarizes recent advancements in self-reporting H₂S donor systems, organizing them based on their activation triggers, such as specific bioanalytes, enzymes, or external stimuli like light. The discussion covers their design strategies, performance in biological applications, and therapeutic potential. Key challenges are also highlighted, including the need for precise control of H₂S release kinetics, accurate signal quantification, and improved biocompatibility. With continued refinement, self-reporting H₂S donors offer great promise for creating multifunctional platforms that seamlessly integrate diagnostic imaging with therapeutic H₂S delivery. Full article

Soluble solids content (SSC) in fruits, as one of the key indicators of fruit quality, plays a critical role in postharvest quality assessment and grading. While traditional destructive methods can provide precise measurements of sugar content, they have limitations such as damaging the fruit’s integrity and the inability to perform rapid detection. In contrast, non-destructive detection technologies offer the advantage of preserving the fruit’s integrity while enabling fast and efficient sugar content measurements, making them highly promising for applications in fruit quality detection. This review summarizes recent advances in non-destructive detection technologies for fruit sugar content measurement. It focuses on elucidating the principles, advantages, and limitations of mainstream technologies, including near-infrared spectroscopy (NIR), X-ray technology, computer vision (CV), electronic nose (EN) technology and so on. Critically, our analysis identifies key challenges hindering the broader implementation of these technologies, namely: the integration and optimization of multi-technology approaches, the development of robust intelligent and automated detection systems, and issues related to high equipment costs and barriers to widespread adoption. Based on this assessment, we conclude by proposing targeted future research directions. These focus on overcoming the identified challenges to advance the development and practical application of non-destructive SSC detection technologies, ultimately contributing to the modernization and intelligentization of the fruit industry. Full article

As the crucial current collector for lithium-ion batteries (LIBs), electrolytic copper foils are generally manufactured by electrodeposition in acidic copper sulfate solution. However, there are many disadvantages for traditional electrolytic copper foils, such as coarse grains, insufficient mechanical properties, and high energy consumption. In order to improve the performances of electrolytic copper foil, a novel cuprous electrodeposition system was developed in this study. A soluble cuprous coordination compound was synthesized. In addition, XPS, FT-IR spectrum, as well as single-crystal X-ray diffraction illustrated that thiourea coordinated with Cu(I) through S atom and therefore stabilized Cu(I) by the formation of CuCl·3TU. Importantly, the corresponding electrochemical behaviors were investigated. In aqueous solution, two distinct reduction processes were demonstrated by linear sweep voltammetry (LSV) at rather negative potentials, including the reduction of adsorbed state and non-adsorbed state. Moreover, the observed inductive loops in electrochemical impedance spectroscopy further confirmed the adsorption phenomenon. More significantly, the designed cuprous electrodeposition system could contribute to low energy consumptions during electrolysis. and produce ultrathin nanocrystalline copper foils with appropriate roughness. Consequently, the electrolysis method based on CuCl·3TU could provide an improved approach for copper foils manufacturing in advanced LIBs fabrication. Full article

The effects of octenyl succinic anhydride-modified hydrophobic starch (OSA starch) on the properties of myofibrillar protein (MP) emulsions were investigated. The results show that the stability of protein emulsions was significantly enhanced with the addition of OSA starch (0.25–1.0%), with the most pronounced effect observed at a 1% concentration. Concomitantly, increasing OSA starch concentrations led to a reduction in the fat globule size. Electrostatic interactions between anionic groups in the modified starch and myofibrillar proteins were observed, which effectively decreased the zeta potential of the emulsion to a minimum of −52.3 mV. However, in the composite emulsion system, a competitive relationship between OSA starch and myofibrillar proteins was evident, as reflected by the decrease in interfacial protein content from 1.16 mg/mL in the control (CK) group to 0.78 mg/mL in the OSA starch-treated group. Despite this competition, the overall emulsion stability was improved due to the synergistic effects of the modified starch and proteins. These findings suggest that OSA-modified starch holds promise as a stabilizer for enhancing the stability of myofibrillar protein emulsions. Full article

Resol phenol–formaldehyde (PF) resin was modified with 2.5 and 5.0 wt% polymethylhydrosiloxane (PMHS). This study characterizes the modified resin and its subsequently fabricated glass fiber (GF)-reinforced composites (30–60 wt% GF). Formation of an organic–inorganic hybrid network, via reaction between Si-H groups of PMHS and hydroxyl (-OH) groups of the resol resin, was confirmed by FTIR and ¹H NMR. DSC and TGA/DTG revealed enhanced thermal stability for PMHS-modified resin: the decomposition temperature of Resol–PMHS 5.0% increased to 483 °C (neat resin: 438 °C), and char yield at 800 °C rose to 57% (neat resin: 38%). The 60 wt% GF-reinforced Resol–PMHS 5.0% composite exhibited tensile, flexural, and impact strengths of 145 ± 7 MPa, 160 ± 7 MPa, and 71 ± 5 kJ/m², respectively, superior to the unmodified resin composite (136 ± 6 MPa, 112 ± 6 MPa, and 51 ± 5 kJ/m²). SEM observations indicated improved fiber–matrix interfacial adhesion and reduced delamination. These results demonstrate that PMHS modification effectively enhances the thermo-mechanical properties of the PF resin and its composites, highlighting potential for industrial applications. Full article

Heat-stable enterotoxin (STa) is a peptide toxin that induces acute diarrhea by binding to guanylyl cyclase C (GC-C) in intestinal epithelial cells. Interestingly, GC-C is highly expressed not only in intestinal cells but also in certain colorectal cancer cells, such as T84 and Caco-2 cells. This unique expression pattern provides STa as an effective candidate for therapeutic applications in cancer suppression or as a probe for detecting cancer cells. Recently, we developed attenuated forms of several STa analogs, including STa topological isomers, and evaluated their efficacy in detecting GC-C on Caco-2 cells, which enables the use of STa in human applications. Therefore, in this study, we investigated the potential application of a ¹⁰B-labeled STa derivative, [Mpr⁵,D-Lys¹⁶(BSH)]-STp(5–17) topological isomer, in boron neutron capture therapy (BNCT), for establishing a novel therapeutic strategy for colorectal cancer. The ¹⁰B-labeled STa peptide clearly exhibited Caco-2 cell killing activity upon neutron irradiation in a concentration-dependent manner, indicating that STa is an effective candidate drug for BNCT. To our knowledge, this is the first report of using STa in boron neutron capture therapy (BNCT). Full article

Complex antimony pyrochlores Bi_2.7M_0.46Ni_0.70Sb₂O_10+Δ (M = Zn, Mg) were synthesized from oxide precursors, using the solid-state reaction method. For each composition variant, the pyrochlore phase formation process was studied during solid-state synthesis in the range of 500–1050 °C. The influence of zinc and magnesium on the phase formation process was established. The interaction of oxide precursors occurs at a temperature of 600 °C and higher, resulting in the formation of bismuth stibate (Bi₃SbO₇) as a binary impurity phase. Oxide precursors, including bismuth(III) and antimony(III,V) oxides, are fixed in the samples up to 750 °C, at which point the intermediate cubic phase Bi₃M_2/3Sb_7/3O₁₁ (sp. gr. Pn-3, M = Zn, Ni) is formed in the zinc system. Interacting with transition element oxides, it is transformed into pyrochlore. An intermediate phase with the Bi_4.66Ca_1.09VO_10.5 structure (sp. gr. Pnnm) was found in the magnesium system. The unit cell parameter of pyrochlore for two samples has a minimum value at 800 °C, which is associated with the onset of high-temperature synthesis of pyrochlore. The synthesis of phase-pure pyrochlores is confirmed by high-resolution Raman spectroscopy. The data interpretation showed that the cations in Ni/Zn pyrochlore are more likely to be incorporated into bismuth positions than in Ni/Mg pyrochlore. The nickel–magnesium pyrochlore is characterized by a low-porosity microstructure, with grain sizes of up to 3 μm, according to SEM data. Zinc oxide has a sintering effect on ceramics. Therefore, the grain size in ceramics is large and varies from 2 to 7 μm. Full article

Cocktail-type catalysis represents a significant shift in the understanding of catalytic processes, recognizing that multiple interconverting species—such as metal complexes, clusters, and nanoparticles—can coexist and cooperate within a single reaction environment. Originating from mechanistic studies on palladium-catalyzed systems, this concept challenges the classical division between homogeneous and heterogeneous catalysis. Instead, it introduces a dynamic framework where catalysts adapt and evolve under reaction conditions, often enhancing efficiency, selectivity, and durability. Using advanced spectroscopic, microscopic, and computational techniques, researchers have visualized the formation and transformation of catalytic species in real time. The cocktail-type approach has since been extended to platinum, nickel, copper, and other transition metals, revealing a general principle in catalysis. This approach not only resolves long-standing mechanistic inconsistencies, but also opens new directions for catalyst design, green chemistry, and sustainable industrial applications. Embracing the complexity of catalytic systems may redefine future strategies in both fundamental research and applied catalysis. Full article

The design of suitable chemosensors for environmental pollutants and toxins detection at trace levels remains a critical area of research. Among various chemosensors, Zn(II) coordination polymers have garnered special interest as fluorescent probes for environmental applications. In this article, we report the synthesis of a nitrogen-rich luminescent Zn(II) coordination polymer, TDPAT-Zn-CP, designed for differential fluorescent sensing of antibiotics in an aqueous medium. TDPAT-Zn-CP was synthesized using a star-shaped 2,4,6-tris(di-2-pyridylamino)-1,3,5-triazine (TDPAT) fluorophore, a promising blue-emitting compound. The morphological and structural properties of TDPAT-Zn-CP were thoroughly analyzed using conventional spectroscopic and analytical techniques. The fluorescence titration studies in aqueous medium demonstrated that TDPAT-Zn-CP exhibits remarkable selectivity, sensitivity, and differential fluorescence sensing responses towards various antibiotics. Among the antibiotics tested, TDPAT-Zn-CP displayed a significant fluorescence quenching and high selectivity for sulfamethazine (SMZ), with a Stern–Volmer quenching constant of K_SV = 1.68 × 10⁴ M⁻¹ and an impressive sensitivity of 4.95 ppb. These results highlight the potential of TDPAT-Zn-CP as a practically useful, highly effective polymeric sensor for the differential fluorescence-based detection of antibiotics in water, offering a promising approach for environmental monitoring and contamination control. Full article

Pharmaceuticals such as diclofenac (DCF), a widely used anti-inflammatory drug, are frequently detected in water bodies and pose serious environmental and health risks due to their persistence and low biodegradability. Although ozonation is an effective method for pollutant removal, its efficiency is often limited by low ozone utilization and incomplete mineralization. In this work, CuO/Al₂O₃- and MnO₂/Al₂O₃-supported catalysts were prepared via an impregnation method and evaluated for their performance in catalytic ozonation of diclofenac (DCF) in an aqueous solution. The catalysts were characterized by TEM, N₂ adsorption–desorption, FTIR, and XPS analyses. The effects of catalyst type, dosage, initial pH, and ozone flow rate on degradation efficiency were systematically investigated. Under optimal conditions, the DCF removal efficiencies reached 73.99% and 76.33% using CuO/Al₂O₃ and MnO₂/Al₂O₃, respectively, while COD removal efficiencies were 77.6% and 89.3%. Quenching experiments indicated that hydroxyl radicals (•OH) were the predominant reactive species involved in the catalytic ozonation process. The results demonstrate that supported CuO and MnO₂ catalysts can effectively enhance diclofenac degradation by ozone, offering potential for advanced water treatment applications. Full article

Pyrazolopyridines and pyrazolopyrimidines are 5:6 aza-fused N-heteroaromatic compounds (NHACs) comprising a pyrazole ring fused to a pyridine or pyrimidine ring. They exhibit dipolar behavior due to their π-excessive and π-deficient characteristics conferred by their five- and six-membered rings. These features favor their stability, reactivity, and structural diversity, offering numerous modular and functional derivatives (e.g., pyrazolo[1,2-a]pyridines, pyrazolo[1,5-a]pyrimidines, etc.). They have been utilized to obtain relevant chemicals in pharmaceuticals, photophysics, industry, and materials science; thus, their synthesis is highly desirable for discovering novel or improved applications. Therefore, this review focuses on recent advances in the synthesis and applications of these compounds, considering reports from the last decade (2015–2024), with particular emphasis on photophysics, as they contain dipolar 5:6 aza-fused rings as essential scaffolds for this purpose. Full article