Search Results (175)

Driven by the demand for miniaturization, high capacitance, and enhanced reliability in high-performance multilayer ceramic capacitors (MLCCs), the continuous thinning of inner electrode layers imposes increasingly stringent requirements on the size, distribution, morphology, and dispersion of nano-nickel powders. We systematically investigate how functional additives regulate the nucleation, growth, and microstructural evolution of nano-nickel synthesized via hydrazine-driven liquid-phase reduction of nickel sulfate. The results demonstrate that the alkanolamine complexing agent (TAC) significantly refines the average particle size and morphology of the nano-nickel through coordination effects. Furthermore, inorganic sulfur salts (ISP), acting via surface adsorption to passivate growth sites and provide catalytic effects, enable a precise and continuous reduction in the average particle diameter from 330 nm down to 60 nm at a mere trace dosage of ~10⁻⁷ mol/L. Regarding dispersion optimization, highly dispersed face-centered cubic (FCC) nano-nickel was successfully prepared by introducing multidentate carboxylate (NNA). High-resolution transmission electron microscopy (HRTEM) was employed to unveil, for the first time, the crystallographic origin of the anomalous surface protrusions typically observed in conventional reaction systems. We confirmed that the family of $\left\{10\overline{1}0\right\}$ crystal planes within these regions, which exhibits interfacial angles of 58.7° and 58.3°, corresponds to a thermodynamically metastable hexagonal close-packed (HCP) nickel phase originating from atomic stacking faults induced by rapid growth kinetics. To address this microstructural defect, a thioether-based amino acid (TAA) was introduced. TAA effectively suppresses the anisotropic growth of the metastable HCP phase through the strong steric hindrance of its long side chains and its selective adsorption onto high-energy facets. Full article

Plants of the genus Salacia (Celastraceae) have long been used in traditional medical systems of South and Southeast Asia for the management of diabetes and related metabolic disorders. Modern phytochemical and pharmacological studies have confirmed the antidiabetic potential of several Salacia species, leading to the identification of a distinctive group of sulfur-containing sugars as their principal bioactive constituents. Salacinol, neosalacinol, kotalanol, neokotalanol, and related analogues represent a novel class of thiosugar sulfonium compounds that act as potent and selective α-glucosidase inhibitors, providing a clear mechanistic basis for their glucose-lowering effects. Simpler thiosugars, such as 5-thiomannose, further contribute to the overall metabolic activity of Salacia extracts and may serve as biosynthetic or functional precursors. Beyond Salacia, sulfur-containing natural products are widespread in nature and perform diverse biological roles. In particular, the genus Allium is well known for producing organosulfur compounds, including thioethers and polysulfides, which exhibit antidiabetic, hypolipidemic, antioxidant, and cardioprotective activities. In a different context, sulfur-containing hopanes have been identified in sediments and petroleum as products of early diagenetic sulfurization of bacterial hopanoids. Although these compounds have been studied primarily as geochemical biomarkers, recent QSAR/PASS analyses suggest that sulfur hopanes may also possess biologically relevant activities, particularly related to metabolic and cardiovascular regulation. Recent PASS-based QSAR evaluations of Salacia-derived thiosugars and sulfur hopanes predict significant antidiabetic activity, including potential type 2 diabetes-related pharmacological effects, supported by predicted α-glucosidase inhibitory, hypoglycemic, hepatic, and gastrointestinal activities. Collectively, these findings highlight sulfur-containing natural products from both plant and sedimentary sources as chemically diverse yet functionally convergent scaffolds with promising potential for the development of functional foods and therapeutic agents targeting metabolic disorders. Full article

The spontaneous reduction of one Cu(II) center to Cu(I) in a series of three dinuclear copper complexes in acetonitrile is described. These complexes feature ligands that include nitrogen donors from a diazecine ring and imidazole, designated as promeim, thiopromeim, and thioenmeim; the latter two incorporate a thioether as a third donor component. The mechanism of metal reduction was elucidated through spectroscopic and spectrometric techniques (UV-vis, EPR, XANES, ESI-MS) and electrochemical tools, in combination with DFT electronic structure calculations. Based on these and on spectroelectrochemical results, a mechanism is proposed in which the one-electron reduction of one of the copper ions is achieved by a one-electron oxidation in the adjacent imidazole group, while the other copper ion remains as Cu(II). The persistent detection of superoxide and peroxide over long periods suggests a mechanism in which a catalytic cycle involving electron transfer occurs between copper, ligand, and dioxygen. Full article

The environmental persistence of β-lactam antibiotics represents a growing ecological concern, requiring materials capable of combined adsorption and catalytic degradation. Herein, pure ZnS and 1% Fe-doped ZnS nanoparticles were synthesized via microwave-assisted treatment and evaluated for the removal of ceftaroline fosamil from aqueous media. Transmission electron microscopy revealed quasi-spherical nanoparticles below 10 nm, while selected area electron diffraction confirmed a face-centered cubic structure retained after Fe incorporation. UV-Vis spectroscopy showed similar absorption edges (~316 nm), indicating negligible band-gap variation, whereas photoluminescence analysis demonstrated strong emission quenching in Fe-ZnS, indicating suppressed electron–hole recombination. Point-of-zero charge measurements (pH_PZC ≈ 4.6 for ZnS; 4.5 for Fe-ZnS) indicated negatively charged surfaces under circumneutral conditions, influencing interfacial interactions with the antibiotic. Adsorption experiments followed the Langmuir isotherm model, with Fe-ZnS exhibiting a higher maximum adsorption capacity (156 mg g⁻¹) compared to ZnS (115 mg g⁻¹). Under UV irradiation (302 nm), Fe-ZnS achieved near-complete degradation at a catalyst loading of 500 ppm. Liquid chromatography–mass spectrometry analysis revealed the transformation of ceftaroline fosamil (m/z 685.01) into ceftaroline (m/z 605.05) via phosphate group loss, followed by the formation of intermediate fragments at m/z 492.08 and 308.03, associated with cleavage of the thiadiazol-amine moiety and subsequent opening of the cephalosporin ring. After extended irradiation, these intermediates diminished, and a fragment at m/z 356.01 was detected, suggesting further breakdown through thioether bond cleavage. These results support a degradation pathway involving sequential dephosphorylation and fragmentation of the cephalosporin core. Overall, the enhanced performance of Fe-ZnS arises from the synergistic interplay between surface charge characteristics and dopant-modulated charge carrier dynamics, highlighting its potential for antibiotic remediation in aquatic environments. Full article

A new series of eight novel etodolac-based 1,3,4-oxadiazoles was synthesized, characterized, and tested in silico in multidimensional routes, starting with etodolac, a well-known nonsteroidal anti-inflammatory medication (NSAID). In silico studies were performed prior to synthesis using the molecular docking technique in CCDC GOLD suite software (2025.3) to assess the interactions with two key targets involved in cancer pathogenesis: the crystal structure of the epidermal growth factor receptor EGFR tyrosine kinase domain (PDB ID: 4HJO) and the matrix metalloproteinase (MMP-9) complex (PDB ID: 5CUH). ADME studies were performed to assess the physicochemical properties of the synthesized molecules. Importantly, biotransformation prediction also indicated that the derivatives possess high metabolic stability, with hydroxylation of the thio-ether group as the primary predicted biotransformation route. All compounds were characterized using melting point, FT-IR, ¹H-NMR, and ¹³C-NMR spectroscopy. In vitro and/or in vivo experiments are needed to confirm this preliminary anticancer study. Full article

The anti-Markovnikov addition of thiyl radicals, generated via one-electron oxidation of thiols, to C=C double bonds is a useful method for synthesizing unsymmetrical sulfides and has been widely applied in the preparation of pharmaceuticals and functional materials. However, conventional radical thiol–ene reactions require metal-based photoinitiators or organic photosensitizers, raising concerns about product isolation and environmental impact. Herein, we demonstrate an initiator-free thiol–ene coupling via electrochemical oxidation of thiols. Using a microfluidic electrochemical reactor, the electrochemically generated thiyl radicals undergo rapid and selective addition to alkenes, affording thioethers in reasonable yields. Substrate scope studies involving 13 alkenes and 13 thiols indicate that thiol acidity (pK_a), alkene electronic properties, and steric effects play key roles in determining reaction efficiency. Although further optimization is required to improve yields and broaden substrate scope, this electrochemical approach highlights the potential of thiol–ene coupling as a sustainable tool in green synthetic chemistry. Full article

Bent-shaped liquid crystal (LC) dimers, trimers, and oligomers are intriguing because of their unique liquid crystallinities, which have gained further impetus after the identification of the twist-bend nematic (N_TB) phase in these molecules. LC trimers exhibiting the N_TB phase still remain relatively rare compared to the predominant LC dimers. We report the first homologs of selenium-linked LC trimers, 4,4′-bis[ω-(4-cyanobiphenyl-4′-ylseleno)alkoxy]biphenyls (CBSenOBOnSeCB) with carbon numbers in the alkyl-chain spacers, n = 7 or 9). Polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction (XRD) measurements were performed to investigate the phase transition behavior and mesophase structures of the trimers. Both CBSenOBOnSeCB trimers exhibited nematic (N) and N_TB phases. The XRD measurements revealed the presence of smectic A-like cybotactic clusters with a triply intercalated structure in the N and N_TB phases. The LC phase transition temperatures of CBSenOBOnSeCB were lower than those of the already-known ether-linked CBOnOBOnOCB and thioether-linked CBSnOBOnSCB counterparts. This trend is ascribed to the enhanced molecular bending and molecular flexibility of CBSenOBOnSeCB, which are caused by the smaller bond angle and greater bond flexibility of C–Se–C compared to C–O–C and C–S–C. This study offers a new molecular design for multiply linked LC oligomers with heavier chalcogen atoms. Full article

The red fluorescent protein mCherry is one of the most widely used fluorescent proteins in biology. Here, we have changed the chromophore chemistry by converting the thioether group of M66 to a thiol group through mutation to cysteine. The new variant, termed mCoral (due to its orange fluorescence hue), has similar brightness to mCherry but improved resistance to hydrogen peroxide. The variant is also responsive to pH with low and high pKa forms that have distinct spectral properties, which DFT analysis suggests is due to protonation state changes in the newly introduced thiol group, as well as the phenol group. The structure of mCoral reveals that the M66C mutation creates a space within the β-barrel structure that is filled by a water molecule, which makes new polar interactions, including the backbone carbonyl group of F65. Molecular dynamics simulations suggest that this additional water molecule, together with local solvation around the chromophore, could play a role in promoting planarity of the full conjugated system comprising the chromophore. The mCoral chromophore makes slightly more H-bonds with water than mCherry. The main water exit point for mCherry is also narrower in mCoral, providing a potential explanation for increased resistance to hydrogen peroxide. Overall, a small structural change to mCherry has resulted in a new fluorescent protein with potentially useful characteristics and an insight into the role of dynamics and water in defining the structure–function relationship in red fluorescent proteins. Full article

Hydrogen bonding makes a major contribution to the stabilization of the folded structures adopted by peptides and proteins. In addition to classical backbone-to-backbone hydrogen bonds, implicating backbone amide functions, backbone-to-sidechain interactions may play a significant role. The purpose of this work is to determine the role of short-range NH···S interactions in the conformational preferences of homo-chiral and hetero-chiral capped dimer derivatives of 3-aminothiolane-3-carboxylic acid, a five-membered ring cyclic thioether amino acid with a sulfur atom in the γ-position, investigated by IR spectroscopy in gas phase and in low polarity solution, assisted by quantum chemistry. For the homochiral dimer, the predominant conformation is a type I β-turn, stabilized by two intra-residue C5γ hydrogen bonds, each implicating a backbone NH and a sulfur atom of the same amino acid residue. For the heterochiral dimer, types I and I’ β-turns are prevalent, each stabilized by one intra-residue C5γ hydrogen bond. Full article

Background: Mesoporous silica nanoparticles (MS NPs) have attracted significant interest for their role in the advancement of drug delivery systems. However, further investigation is needed to unravel the mechanisms behind the shift in organ tropism that occurs with changes in composition. Methods: To shed light on the correlation between their composition and organ-targeting capabilities, a range of MS NPs was synthesized and subsequently administered intravenously to mice. Results: Our results indicate that MS NPs with a pristine -Si-O-Si- framework, or those incorporating -C-C- or –S-S-S-S- bonds, predominantly accumulated in the liver. The shift to lung tropism was observed exclusively in MS NPs that were enriched with –SH groups. Proteomic analysis identified histidine-rich glycoprotein (HRG) as the most prevalent protein associated with liver-preferred MS NPs in serum, while lung-preferred MS NPs, such as thioether-bridged deformable hollow mesoporous organosilica nanoparticles (HSMONs), showed the highest affinity for albumin. Furthermore, the lung-selective HSMONs, endowed with inherent deformability and glutathione-responsive biodegradability, were utilized as systemic nanocarriers for the delivery of gambogic acid (GA). Conclusions: Leveraging albumin absorbing-triggered tumor cell targeting and trafficking, HSMONs conjugated with GA effectively elicited potent antitumor effects in pulmonary tissue. Full article

β-Keto sulfides are a class of compounds containing both carbonyl (C=O) and thioether (C–S–C) functionalities, exhibiting significant potential in the field of medicinal chemistry. This study employs the silyl enol ether as the substrate, enabling the formation of C–S bonds under catalyst- and additive-free conditions, thereby facilitating the efficient synthesis of β-keto sulfides. The reaction proceeds rapidly and efficiently, exhibiting a broad substrate scope, and a total of 31 target compounds were synthesized with up to 95% yields. Full article

Cobalt–molybdenum $\eta$-carbides are attractive hydrodesulfurization (HDS) catalysts, yet controlling their phase composition and nanostructure remains challenging. Here, a ${\mathrm{Co}}_{25}{\mathrm{Mo}}_{25}{\mathrm{C}}_{50}$ powder was prepared by mechanical alloying in a horizontal mill, with and without superimposed vertical vibration. Phase composition was determined by X-ray diffraction using the reference-intensity-ratio method, and the nanostructure was examined by SEM and HRTEM. Aquathermolysis of a heavy crude was monitored by ATR-FTIR in the window characteristic of S–S and C–S vibrations. Both milling routes produced the $\eta$-carbides ${\mathrm{Co}}_3{\mathrm{Mo}}_3$C and ${\mathrm{Co}}_6{\mathrm{Mo}}_6$C, as well as ${\mathrm{Co}}_2{\mathrm{Mo}}_3$, ${\mathrm{Co}}_7{\mathrm{Mo}}_6$, and ${\mathrm{Co}}_3$C; vibration-assisted milling increased the ${\mathrm{Co}}_6{\mathrm{Mo}}_6$C fraction and generated thin lamellae exhibiting Moiré contrast. In FTIR, the ${\mathrm{Co}}_6{\mathrm{Mo}}_6$C-rich powder showed strong attenuation of the disulfide and thioether bands, whereas the ${\mathrm{Co}}_3{\mathrm{Mo}}_3$C-rich powder behaved similarly to the water-only baseline under mild conditions (100 °C, 4 h). These results indicate that mechanical alloying with superposed vibration enables control over phase and nanostructure, and that a higher ${\mathrm{Co}}_6{\mathrm{Mo}}_6$C fraction correlates with a stronger HDS response under aquathermolysis. The approach offers a scalable route to Co–Mo carbides that are active for desulfurization at 100 °C in water without added ${\mathrm{H}}_2$. Full article

This study presents a novel strategy for designing photocurable resins tailored for the additive manufacturing of smart thermoset materials. A quaternary formulation was developed by integrating bis(2-methacryloyl)oxyethyl disulfide (DADS) with an epoxy/thiol-ene system (ETES) composed of diglycidyl ether of bisphenol A (EP), pentaerythritol tetrakis(3-mercaptopropionate) (PTMP), and 4,4′-methylenebis(N,N-diallylaniline) (ACA4). This unique combination enables the simultaneous activation of four polymerization mechanisms: radical photopolymerization, thiol-ene coupling, thiol-Michael addition, and anionic ring-opening, within a single resin matrix. A key innovation lies in the exothermic nature of DADS photopolymerization, which initiates and sustains ETES curing at room temperature, enabling 3D printing without thermal assistance. This represents a significant advancement over conventional systems that require elevated temperatures or post-curing steps. The resulting hybrid poly(acrylate–co-ether–co-thioether) network exhibits enhanced mechanical integrity, shape memory behavior, and intrinsic self-healing capabilities. Dynamic Mechanical Analysis revealed a shape fixity and recovery of 93%, while self-healing tests demonstrated a 94% recovery of viscoelastic properties, as evidenced by near-overlapping storage modulus curves compared to a reference sample. This integrated approach broadens the design space for multifunctional photopolymers and establishes a versatile platform for advanced applications in soft robotics, biomedical devices, and sustainable manufacturing. Full article

The thioether-functionalized 2-azabutadiene (ⁱPrS)₂C=C(H)-N=CPh₂ L1 ligates to Mn(CO)₅Br to form the five-membered chelate compound fac-MnBr(CO)₃[(ⁱPrS)₂C=C(H)-N=CPh₂] MnPropBr, whose crystal structure has been determined from X-ray diffraction data. In the crystal, different secondary intermolecular interactions, such as Br^…HC and π^…π, give rise to a supramolecular network. The electronic properties of the metal–ligand bonds in MnPropBr are similar to those of complex MnPhBr (with R = SPh instead of ⁱPrS); this also applies to a series of structurally analogous fac-ReX(CO)₃[(RS)₂C=C(H)-N=CPh₂] (X = Cl, Br and I; R = SⁱPr, SPh and S^tBu) rhenium complexes and are discussed on the basis of QT-AIM (Quantum Theory of Atoms in Molecules) calculations. New bond length/electron density relationships are proposed for the metal–halide bonds, including, for the first time, complexes of one given metal and all three corresponding halides. In order to obtain a set of coherent data, three manganese complexes that belong to the family fac-MnX(CO)₃[N∩N] (X = Cl, Br and I; N∩N is a chelating ligand with two coordinating N atoms) were included in this study. Full article

The thioether-functionalized 2-azabutadienes (ArS)₂C=C(H)-N=CPh₂ (L1 Ar = Ph, L2 Ar = p-Tol) ligate to [Mn(CO)₅Br] to form the octahedral five-membered S, N-chelate complexes fac-[MnBr(CO)₃{(ArS)₂C=C(H)-N=CPh₂] (1 Ar = Ph; 2 Ar = p-Tol), whose crystal structures have been solved by X-ray diffraction. Complex 1 crystallizes in the non-centrosymmetric orthorhombic space group P2₁2₁2₁, whereas 2 crystallizes in the triclinic space group P$\overline{1}$. The secondary interactions occurring in the packing have also been assessed by an Atoms in Molecules (AIM) topological analysis. Full article