Chemistry

To develop new hybrid anticancer agents, 3,5-bis(benzylidene)-4-piperidone scaffolds (compounds 1–6) were functionalized with (1R)-borneoyl chloroacetate (8) or (1S)-camphorsulfonyl chloride (10). Covalent attachment of the camphorsulfonyl moiety via N-sulfonylation yielded hybrid molecules (16–21) that exhibited selective cytotoxic and cytostatic activity against cancer cells, with submicromolar IC₅₀ values. In silico ADME analysis indicated that these camphorsulfonyl-conjugated piperidones have improved drug-like properties (enhanced absorption, metabolism, and bioavailability) compared to curcumin. The most potent analogs were halogen-substituted and trimethoxy-substituted analogs, which showed the strongest tumor cell growth inhibition while sparing normal cells. Overall, this terpene-functionalization strategy addresses curcumin’s pharmacokinetic limitations and improves its anticancer profile. These hybrid molecules hold promise as potential anticancer agents. Full article

To address the greenhouse effect and environmental pollution stemming from fossil fuels, the development of new energy sources is widely regarded as a critical pathway toward achieving carbon neutrality. Microalgae, as a feedstock for third-generation biofuels, have emerged as a research hotspot for producing biojet fuel due to their high photosynthetic efficiency, non-competition with food crops, and potential for carbon reduction. This paper provides a systematic review of technological advancements in the catalytic hydrogenation of microalgal oil for biojet fuel production. It specifically focuses on the reaction mechanisms and catalyst design involved in the hydrogenation–deoxygenation and cracking/isomerization processes within the Oil-to-Jet (OTJ) pathway. Furthermore, the paper compares the performance differences among various catalyst support materials and between precious and non-precious metal catalysts. Finally, it outlines the current landscape of policy support and progress in industrialization projects globally. Full article

Biosensing plays a vital role in medical diagnostics, environmental monitoring, and food safety, enabling highly sensitive and specific detection of diverse biological and chemical targets. However, conventional biosensing platforms still suffer from limited sensitivity, poor nanoscale resolution, and restricted multiplexed or dynamic detection capabilities. DNA origami, as an emerging bottom-up nanofabrication strategy, enables the construction of programmable nanostructures with high spatial precision. This capability allows the rational arrangement of functional molecules at the nanoscale, thereby offering significant advantages for biosensing applications. Specifically, DNA origami can enhance signal amplification, improve spatial resolution, and enable multiplexed detection under complex conditions. In this review, we provide a systematic overview of recent advances in the application of DNA origami across various classes of biosensors, including microscopy-based biosensors, nanopore biosensors, electrochemical biosensors, fluorescent biosensors, SERS biosensors, and other related biosensors. We aim for this review to advance the development of DNA origami-based biosensing and to provide new insights for researchers working in related fields. Full article

Non-perturbative approaches to linear and nonlinear responses (NLR) of atoms, molecules, and molecular aggregates are reviewed in relation to low and high harmonic generations (HG) by laser fields. These response properties are effective for the generation of entangled light pairs for quantum information processing by spontaneous parametric downconversion (SPDC) and stimulated four-wave mixing (SFWM). Quasi-energy derivative (QED) methods, such as QED Møller–Plesset (MP) perturbation, are reviewed as time-dependent variational methods (TDVP), providing analytical expressions of time-dependent linear and nonlinear responses of open-shell atoms, molecules, and molecular aggregates. Numerical Liouville methods for the low HG (LHG) and high HG (HHG) regimes are reviewed to elucidate the NLR of molecules in both LHG and HHG regimes. Three-step models for the generation of HHG in the latter regime are reviewed in relation to developments of attosecond science and spectroscopy. Orbital tomography is also reviewed in relation to the theoretical and experimental studies of the amplitudes and phases of wave functions of open-shell atoms and molecules, such as molecular oxygen, providing the Dyson orbital explanation. Interactions between quantum lights and molecules are theoretically examined in relation to derivations of several distribution functions for quantum information processing, quantum dynamics of molecular aggregates, and future developments of quantum molecular devices such as measurement-based quantum computation (MBQC). Quantum dynamics for energy transfer in dendrimer and related light-harvesting antenna systems are reviewed to examine the classical and quantum dynamics behaviors of photosynthesis. It is shown that quantum coherence plays an important role in the well-organized arrays of chromophores. Finally, applications of quantum optics to molecular quantum information and quantum biology are examined in relation to emerging interdisciplinary frontiers. Full article

Thiochromen-4-ones are known to possess useful optical properties and rich bioactivities, including antioxidant, antimicrobial, and anticancer properties. They are known to inhibit tumor cell growth, induce apoptosis, and have antiplatelet aggregation effects. Thiochromen-4-ones are also used as synthons and precursors in organic synthesis for bioactive agents. Although many synthetic approaches to oxygen-containing counterparts, chromones, have been reported, research on the synthesis of thiochromen-4-ones is scarce. The synthesis of thiochromen-4-ones can be challenging due to the inherent nature of sulfur, including its multiple oxidation states and tendency to form diverse bonding patterns. Here, we report the one-pot synthesis of thiochromen-4-ones, where two transformations of the starting material, 3-(arylthio)propanoic acid, are performed within a single reaction vessel, eliminating the need for an intermediate purification step. This one-pot reaction worked well with a variety of substrates with both electron-withdrawing and donating groups on the aromatic ring of 3-(arylthio)propanoic acids to give thiochromen-4-ones with good yields (up to 81%). This approach offers advantages like time and cost savings, increased efficiency, and reduced waste. This synthetic approach will allow access to a broader scope of thiochromen-4-ones due to the readily available thiophenols. Full article

Five different 2,4-difluorobenzamide derivatives were synthesized and fully characterized by ¹H/¹³C/¹⁹F/2D NMR spectroscopy using DMSO-d₆ as solvent and MS. All compounds occur as rotation conformers resulting from the partial amide double bond with a solvent-dependent coalescence point. Temperature-dependent ¹H NMR techniques, as well as EXSY, were applied to determine the rate constants of exchange, and the resulting activation energy barriers were calculated. Regarding the N,N-diacylated piperazine, both conformers (syn and anti) were found in solution, whereas only the anti-conformer was found in the crystals. This result was verified by an XRD analysis. Single crystals of N,N-bis(2,4-difluorobenzoyl)piperazine 3b (monoclinic, space group P2₁/c, a = 7.2687(3), b = 17.2658(8), c = 6.9738(3) Å, β = 115.393(2)°, V = 790.65(6) ų, Z = 4, D_obs = 1.530 g/cm³) were obtained from a saturated chloroform solution. Full article

Molecular dynamics simulations were conducted using the attachment energy (AE) model to investigate the growth morphology of lead 2,4,6-trinitrororesorcinate (LTNR, lead styphnate) under vacuum and different solvents. The adsorption energy of LTNR on (001), (110), (011), (020), (111), (200), and (201) crystal planes were calculated. Meanwhile, the crystal morphology in solvents of ethanol, toluene, dichloromethane, acetone, dimethyl sulfoxide (DMSO), and water at 298 K was predicted by calculating the interaction energies between the solvents and crystal planes. The calculated results show that the morphology of LTNR crystals in different solvents is significantly different. In toluene, LTNR crystal morphologies are flat, while in pure solvents of ethanol, acetone, and DMSO, the number of crystal planes increases, and the crystal thickness is larger. In the water, LTNR tends to form tabular crystals, which is similar to the experimental results. Both radial distribution function (RDF) and mean squared displacement (MSD) analyses reveal that hydrogen bonding dominates the interactions between LTNR and solvent molecules. Solvent molecules with higher diffusion coefficients exhibit increased desorption tendencies from crystal surfaces, which may reduce their inhibitory effects on specific crystallographic planes. However, no direct correlation exists between solvent diffusion coefficients and crystal plane growth rates, suggesting that surface attachment kinetics or interfacial energy barriers play a more critical role in crystal growth. Full article

The goal of this study is to estimate the amount of lost data in electron microscopy and to analyze the extent to which experimentally acquired images are utilized in peer-reviewed scientific publications. Analysis of the number of images taken on electron microscopes at a core user facility and the number of images subsequently included in peer-reviewed scientific journals revealed low efficiency of data utilization. Up to around 90% of electron microscopy data generated during routine instrument operation can remain unused. Of the more than 150,000 electron microscopy images evaluated in this study, only approximately 3500 (just over 2%) were made available in publications. For the analyzed dataset, the amount of lost data in electron microscopy can be estimated as >90% (in terms of data being recorded but not being published in peer-reviewed literature). On the one hand, these results highlight a shortcoming in the optimal use of microscopy images; on the other hand, they indicate the existence of a large pool of electron microscopy data that can facilitate research in data science and the development of AI-based projects. The considerations important to unlock the potential of lost data are discussed in the present article. Full article

Gold nanoparticles (AuNPs) are attracting more and more attention in life sciences, especially due to their versatile physicochemical properties whereby their colloidal stability in water and organic solvents is crucial. In this study, a systematic comparison of different polymers, synthesis methods and solvents was carried out. The AuNPs were synthesized using the ligand exchange reaction/postsynthetic addition reaction (PAR) and the one-pot synthesis with the polymers poly(vinyl alcohol) (PVA), poly(ethylene glycol) (PEG), poly(vinylpyrrolidone) (PVP) and poly(acrylic acid) (PAA), each with different molar weight averages. Analysis of the AuNP@Polymer conjugates by transmission electron microscopy (TEM) finds essentially unchanged gold nanoparticle core sizes of 11–18 or 11–19 nm in water and ethanol, respectively. The hydrodynamic diameter from dynamic light scattering (DLS) lies largely in the range from 20 to 70 nm and ultraviolet-visible spectroscopy (UV-Vis) showed gold plasmon resonance band maxima between 517 and 531 nm over both synthesis methods and solvents for most samples. The polymer PVA showed the best colloidal stability in both synthesis methods, both in water and after transfer to ethanol. An increased instability in ethanol could only be noted for the PEG coated samples. For the polymers PVP and PAA, the stability depended more specifically on the combination of synthesis method, polymer molecular weight and solvent. Full article

A straightforward synthetic method is advanced to produce hard-to-reach polycyclic compounds belonging to the [1,2,5]oxadiazolo[3,4-b]quinoxaline ring system. This approach draws on a combination of the nucleophilic aromatic substitution of hydrogen (S_N^H) and Scholl cross-coupling reactions, followed by reduction of the 1,2,5-oxadiazole fragment under mild reaction conditions. All compounds were obtained for the first time with moderate to excellent yields. Electrochemical and photophysical measurements show that the synthesized compounds may serve as narrow-band n-type organic semiconductors, with energy levels ranging from 2.00 to 2.28 eV, comparable to those of the best commercially available electronic semiconductors. Full article

The reaction of 4,4′-bipyridine (C₁₀H₈N₂) with the alkali metal pentacyanocyclopentadienides [Na{C₅(CN)₅}(MeOH)] and [KC₅(CN)₅] gives the coordination polymers [Na{C₅(CN)₅}(EtOH)(H₂O)(C₁₀H₈N₂)] (1) and [K{C₅(CN)₅}(H₂O)₂] • 2 (C₁₀H₈N₂) (2) after recrystallization from EtOH. Both compounds show octahedral coordination around the metal ion with a NaN₄O₂ and KN₂O₄ environment. The [C₅(CN)₅] acts as a 1,1-bridging ligand in 1 and a 1,2-bridging ligand in 2. The 4,4′-bipyridine acts as a N,N′-bridging ligand between dimeric [Na₂(EtOH)₂(H₂O)₂(µ-{C₅(CN)₅}₂] units, while it acts only as a guest molecule in the voids between polymeric [K(µ-H₂O)_4/2{µ-C₅(CN)₅}_2/2]_∞ chains. Both compounds employ multiple hydrogen bonds and π stacking to stabilize the crystalline structures. Full article

An increase in the production of cationic dyes is expected over the next decade, which will have an impact on health and the environment. This work reports an adsorbent hydrogel composed of poly(acrylic acid) [poly(AA)] and Fe₃O₄ particles, prepared by radical polymerization and in situ co-precipitation of Fe³⁺ and Fe²⁺. This Fe₃O₄/poly(AA) composite hydrogel was used to evaluate its potential for removing the cationic dyes methylene blue (MB) and crystal violet (CV) from aqueous solutions. Instrumental characterization of the hydrogel was performed by FTIR, XRD, TGA, VSM, and physicochemical analysis (swelling and response to changes in pH). The results show that the incorporation of Fe₃O₄ particles improves the adsorption capacity of MB and CV dyes to a maximum adsorption of 571 and 321 mg/g, respectively, under the best conditions (pH 6.8, dose 1 g/L, time 24 h). The adsorption data best fit the pseudo-first order (PFO) kinetic model and the Freundlich isothermal model, indicating mass transfer via internal and/or external diffusion and active sites with different adsorption potentials. Moreover, the thermodynamic analysis confirmed that the adsorption process was spontaneous and exothermic, with physisorption as the dominant mechanism. In addition, the Fe₃O₄/poly(AA) hydrogel is capable of removing 95% of the dyes after ten consecutive adsorption–desorption cycles, demonstrating the potential of hydrogels loaded with Fe₃O₄ particles for the treatment of wastewater contaminated with dyes. Full article

Density functional theory calculations are performed to examine the reactivity of the coordinatively unsaturated (NH₃)₄RhO²⁺, (NH₃)₄CoO²⁺, and (NH₃)₄FeO⁺ species with methane and methanol. The ground low-spin state of rhodium oxide provides ideal energetics for the efficient and selective conversion of methane to methanol. The small activation energy barriers for all three steps (H₃C-H activation, CH₃-OH recombination, oxygen reload) promise fast conversion, while the larger activation barrier for the C-H activation of methanol provides the means to kinetically hinder further oxidation to the thermodynamically more favorable formaldehyde. The key finding was that rhodium prefers the 2 + 2 (as opposed to radical) activation mechanism of methane. To maintain the “ideal” electronic structure observed for (NH₃)₄RhO²⁺, we first replaced rhodium with its first-row lower cost counterpart cobalt. The cobalt complex favors a quartet state, which prefers a radical mechanism leading to the formation of methyl radical. This undesired effect vanishes, switching from Co⁴⁺ to Fe³⁺. Possible explanations for the observed trends are provided in terms of electronic structure features of the three metals. The production of methanol from methane has been a topic of intense interest over the past decades and we believe that this work offers new insights for tackling this challenging problem. Full article

Advancing catalysts for low-temperature NH₃-SCR enhances their viability as a terminal flue gas denitration solution across diverse operating regimes. A high-performance, hydrothermally stable catalyst for low-temperature SCR was synthesized by depositing MnO_x onto MgAlO_x composite oxide supports. These supports, featuring varied Mg/Al ratios, originated from layered double hydroxide (LDH) precursors. The obtained catalyst with the Mg/Al ratio of 2 (Mn/Mg₂AlO_x) possesses relatively high concentrations of active oxygen species (O_α) and Mn⁴⁺ and exhibits remarkable catalytic performance. The Mn/Mg₂AlO_x catalyst exhibits a wide operating temperature range (100–300 °C) for denitration, achieving over 80% NO_x conversion, along with robust water resistance. The temperature-programed surface reactions and NO oxidation reactions are performed to elucidate the promoting effect of water on N₂ selectivity, which is not only due to inhibition of catalyst oxidation capacity at high temperature but also is related to the competing adsorption of water and NH₃. In situ DRIFTS analysis confirmed that the NH₃-SCR mechanism over Mn/Mg₂AlO_x adheres to the Eley–Rideal (E–R) pathway. These findings highlight the significant promise of Mn/MgAlO_x catalysts for deployment as downstream denitration units within exhaust treatment systems. Full article

With the rapid industrialization, excessive reliance on fossil fuels has resulted in energy crises and environmental pollution, driving the search for sustainable alternatives. Biomass-derived resources have emerged as promising candidates to replace fossil-based feedstocks. Among these, furfural (FF) serves as a key platform molecule that can be catalytically hydrogenated to various high-value chemicals, with furfuryl alcohol (FA) representing one of the most valuable products. Currently, Cr-based catalysts remain predominant for the selective hydrogenation of FF to FA. However, the severe environmental toxicity of Cr necessitates urgent development of alternative Cr-free catalytic systems. This study systematically reviews recent advances in FF hydrogenation to FA, providing an in-depth discussion of reaction mechanisms, including adsorption configurations, solvent effects, and side reactions, as well as a comprehensive analysis of structure–activity relationships, involving active metal, support, promoter, and preparation methods. Furthermore, we evaluate the application of the advanced characterization techniques for monitoring the reaction processes. Finally, we propose the future research directions: (1) designing efficient and stable non-noble metal catalysts and (2) elucidating reaction mechanisms via the combined in situ characterization and theoretical calculations. These efforts would facilitate the academic understanding and industrial implementation of the FF-to-FA conversion process. Full article

The activation of carbon dioxide by transition metal complexes is a fundamental process in catalysis and carbon capture. In this study, density functional theory (DFT) calculations, combined with Quantum Theory of Atoms in Molecules (QTAIM) and Natural Orbitals for Chemical Valency (NOCV) analyses, were employed to investigate the bonding characteristics and electronic structure of Fe(0)–, Pd(0)–, and Pt(0)–phosphine complexes with CO₂. The Fe(0) complexes exhibited the strongest CO₂ activation, characterized by substantial C=O bond elongation, significant charge transfer, and strong $\pi$-backdonation. In contrast, Pd(0) complexes showed minimal CO₂ activation, while Pt(0) complexes displayed intermediate behavior. The electronic effects of phosphine ligands were also analyzed, revealing that electron-donating phosphines enhance CO₂ activation, whereas electron-withdrawing phosphines weaken metal–CO₂ interactions. These findings provide key insights into the design of transition-metal-based catalysts for CO₂ conversion and utilization. Full article

A series of twenty-five salicylic acid derivatives was synthesized and structurally characterized by ¹H and ¹³C-APT NMR and IR spectroscopic techniques, and HRMS analysis. The derivatives were subjected to biological evaluation against species of the genus Candida (C. albicans ATCC 90028, C. albicans CBS 5602, C. tropicalis CBS 94, and C. krusei CBS 573). In assays were used the broth microdilution method to determine the minimum inhibitory concentration (MIC) and verify the probable mechanism of action for antifungal activity. In the antifungal evaluation, compounds N-isobutyl-2-hidroxybenzamide (14), N-cyclohexyl-2-hydroxybenzamide (15), N-benzyl-2-hydroxybenzamide (16), N-4-methylbenzyl-2-hydroxybenzamide (17), N-4-methoxybenzyl-2-hydroxybenzamide (18), N-2,4-dimethoxybenzyl-2-hydroxybenzamide (19), N-4-fluorbenzyl-2-hiydroxybenzamide (22), and N-4-chlorobenzyl-2-hydroxybenzamide (23) were bioactive against at least one fungal strain. The compound with the best antifungal profile was N-cyclohexyl-2-hydroxybenzamide (15), which presented a MIC of 570.05 μM against most of the strains tested. The tests using ergosterol and sorbitol demonstrated that the compound does not act by altering cell wall functions or the plasmatic membrane in Candida species. The in silico analysis of 15 for antifungal activity in various biological targets suggested a probable multitarget mechanism. Therefore, the synthesis of salicylic acid derivatives resulted in compounds with a good antifungal profile. Full article

Lead-free perovskite variants have emerged as promising candidates due to their self-trapped exciton emission. However, in ASnX₃ systems, facile oxidation of Sn(II) to Sn(IV) yields A₂SnCl₆ vacancy-ordered derivatives. Paradoxically, despite possessing a direct bandgap, these variants exhibit diminished photoluminescence (PL). Doping engineering thus becomes essential for precise optical tailoring of A₂SnX₆ materials. Herein, through integrated first-principles calculations and spectroscopic analysis, we elucidate the luminescence mechanism in Te⁴⁺-doped (NH₄)₂SnCl₆ lead-free perovskites. Density functional theory, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) confirm Te⁴⁺ substitution at Sn sites via favorable chemical potentials. Spectral interrogations, including absorption and emission profiles, reveal that the intense emission originates from the triplet STE recombination (³P₁ → ¹S₀) of Te centers. Temperature-dependent PL spectra further demonstrate strong electron–phonon coupling that induces symmetry-breaking distortions to stabilize STEs. Complementary electronic band structure and molecular orbital calculations unveil the underlying photophysical pathway. Leveraging these distinct thermal responses of PL intensity and peak position, 0.5%Te:(NH₄)₂SnCl₆ emerges as a highly promising candidate for non-contact, dual-parameter optical thermometry over an ultra-broad range (100–400 K). This work provides fundamental insights into the exciton dynamics and thermal engineering of optical properties in this material system, establishing its significant potential for advanced temperature-sensing applications. Full article

The chemical composition of Rosa alba L. aromatic products extracted with liquified 1,1,1,2-tetrafluoroethane (freon R134a) has been evaluated in static and dynamic modes of extraction. The yield varies in the range 0.039–0.048% for the different variants. In order to reveal the chemical composition and aroma profile of the extracts, they were analyzed by means of gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). As a result of the analysis, more than 80 compounds with concentrations higher than 0.01% were identified and quantified in the extracts, representing 92.7, 88.4, and 88.0% of the total content. The study indicated that 2-phenyl ethanol (12.57–14.97%), geraniol (12.09–14.82%), nerol (5.90–6.39%), benzyl alcohol (3.63–5.34%), and citronellol (3.21–4.04%) were the main components of the aroma-bearing fraction. The solid phase consists mainly of nonadecane+nonadecene (15.21–16.85%), heneicosane (11.81–13.78%), and tricosane (2.46–2.96%). In addition, olfactory evaluation of the extracts was performed. The comprehensive assessment of the quantitative and qualitative characteristics of the extracts indicates that the static, one-stage mode is the most appropriate for the subcritical extraction of R. alba blossoms with freon R134a. Full article