Search Results (956)

1,4-Thiazine S,S-dioxide 1, the cis- and trans-isomers 2 and 3 of its precursor 2,6-diethoxy-1,4-oxathiane S,S-dioxide, and diethyl 2,3-dihydro-1,4-thiazine-3,5-dicarboxylate S,S-dioxide 4 have been fully characterised, both in solution by ¹H and ¹³C NMR and in the solid state by X-ray diffraction. Simulation has been used to model the unexpectedly complex ¹H NMR spectra and arrive at a full assignment of all chemical shifts and coupling constants. The crystal structures of both 1 and 4, which adopt, respectively, boat and half-chair conformations, are dominated by strong NH to O=S hydrogen bonding leading to chains of molecules. In the case of 4, the NMR data point to an equatorial position of the C(2)-ester group in solution, while in the crystal, this adopts an axial orientation. Compounds 2 and 3 adopt chair conformations both in solution and in the solid state with ring inversion on the NMR timescale leading to unexpected simplification of the spectra in the case of 3. Full article

In this study, supramolecular inclusion complexes composed of komecosanol (Ko), a lipophilic compound derived from rice bran, and α-cyclodextrin (αCD) were prepared using a solvent-free three-dimensional (3D) ball milling method. Their physicochemical properties were examined using various techniques. Powder X-ray diffraction analysis of the ground mixture at a Ko/αCD ratio of 1/8 revealed the disappearance of diffraction peaks characteristic of Ko and the emergence of new peaks, indicating the formation of a distinct crystalline phase. Moreover, differential scanning calorimetry analysis showed the disappearance of the endothermic peaks corresponding to Ko, indicating molecular-level interactions with αCD. Near-infrared spectroscopy results suggested the formation of hydrogen bonds between the C–H groups of Ko and the O–H groups of αCD. Solid-state ¹³C CP/MAS NMR and T₁ relaxation time measurements indicated the formation of a pseudopolyrotaxane structure, while scanning electron microscopy images confirmed distinct morphological changes consistent with complex formation. These findings demonstrate that 3D ball milling facilitates the formation of Ko/αCD inclusion complexes with a supramolecular architecture, providing a novel approach to improve the formulation and bioavailability of poorly water-soluble lipophilic compounds. Full article

Solid-state lithium batteries (SSLBs) have emerged as a promising alternative to conventional lithium-ion systems due to their superior safety profile, higher energy density, and potential compatibility with lithium metal anodes. However, a major challenge hindering their widespread deployment is the formation and growth of lithium dendrites, which compromise both performance and safety. This review provides a comprehensive and structured overview of recent advances in dendrite suppression strategies, with special emphasis on the role played by the nature of the solid electrolyte. In particular, we examine suppression mechanisms and material innovations within the three main classes of solid electrolytes: sulfide-based, oxide-based, and polymer-based systems. Each electrolyte class presents distinct advantages and challenges in relation to dendrite behavior. Sulfide electrolytes, known for their high ionic conductivity and good interfacial wettability, suffer from poor mechanical strength and chemical instability. Oxide electrolytes exhibit excellent electrochemical stability and mechanical rigidity but often face high interfacial resistance. Polymer electrolytes, while mechanically flexible and easy to process, generally have lower ionic conductivity and limited thermal stability. This review discusses how these intrinsic properties influence dendrite nucleation and propagation, including the role of interfacial stress, grain boundaries, void formation, and electrochemical heterogeneity. To mitigate dendrite formation, we explore a variety of strategies including interfacial engineering (e.g., the use of artificial interlayers, surface coatings, and chemical additives), mechanical reinforcement (e.g., incorporation of nanostructured or gradient architectures, pressure modulation, and self-healing materials), and modifications of the solid electrolyte and electrode structure. Additionally, we highlight the critical role of advanced characterization techniques—such as in situ electron microscopy, synchrotron-based X-ray diffraction, vibrational spectroscopy, and nuclear magnetic resonance (NMR)—for elucidating dendrite formation mechanisms and evaluating the effectiveness of suppression strategies in real time. By integrating recent experimental and theoretical insights across multiple disciplines, this review identifies key limitations in current approaches and outlines emerging research directions. These include the design of multifunctional interphases, hybrid electrolytes, and real-time diagnostic tools aimed at enabling the development of reliable, scalable, and dendrite-free SSLBs suitable for practical applications in next-generation energy storage. Full article

This study aims to evaluate eco-innovative solutions in the fertilizer industry that allow for waste valorization in the context of a resource-efficient circular economy. A comprehensive reuse strategy was developed for low-rank peat and post-cultivation horticultural mineral wool, involving the extraction of valuable humic substances from peat and residual nutrients from used mineral wool, followed by the use of both post-extraction residues to produce organic–mineral substrates. The resulting products/semifinished products were characterized in terms of their composition and properties, which met the requirements necessary to obtain the admission of this type of product to the market in accordance with the Regulation of the Minister for Agriculture and Rural Development of 18 June 2008 on the implementation of certain provisions of the Act on fertilizers and fertilization (Journal of Laws No 119, item 765). Elemental analysis, FTIR spectroscopy, and solid-state CP-MAS ¹³C NMR spectroscopy suggest that post-extraction peat has a relatively condensed structure with a high C content (47.4%) and a reduced O/C atomic ratio and is rich in alkyl-like matter (63.2%) but devoid of some functional groups in favor of extracted fulvic acids. Therefore, it remains a valuable organic biowaste, which, in combination with post-extraction waste mineral wool in a ratio of 60:40 and possibly the addition of mineral nutrients, allows us to obtain a completely new substrate with a bulk density of 264 g/m³, a salinity of 7.8 g/dm³ and a pH of 5.3, with an appropriate content of heavy metals and with no impurities, meeting the requirements of this type of product. A liquid fertilizer based on an extract containing previously recovered nutrients also meets the criteria in terms of quality and content of impurities and can potentially be used as a fertilizing product suitable for agricultural crops. This study demonstrates a feasible pathway for transforming specific waste streams into valuable agricultural inputs, contributing to environmental protection and sustainable production. The production of a new liquid fertilizer using nutrients recovered from post-cultivation mineral wool and the preparation of an organic–mineral substrate using post-extraction solid residue is a rational strategy for recycling hard-to-biodegrade end-of-life products. Full article

The reaction of 2-(3-chloro-5-phenyl-4H-1,2,6-thiadiazin-4-ylidene)malononitrile with ammonia in anhydrous THF, at ca. 20 °C, for 24 h, gave 6-amino-4-phenylpyrrolo[2,3-c][1,2,6]thiadiazine-5-carbonitrile in 95% yield. The product was characterized by ¹H and ¹³C NMR, SC-XRD, MALDI-TOF mass spectrometry, FTIR, and UV-vis spectroscopy. Intermolecular hydrogen bonding interactions were observed in the solid state between the C≡N and N-H groups of adjacent molecules. 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

A triphenylphosphine-functionalized silica gel material, optimized for lead adsorption, was synthesized via a one-pot sol–gel reaction and characterized using FTIR and solid-state ¹³C and ²⁹Si NMR and XPS spectroscopy. The interaction between lead cations and phosphine groups was evaluated using the ³¹P NMR chemical shift tensor as a sensor. Two distinct types of phosphine groups, exhibiting different rotational mobility behaviors, were identified, with their ratio influenced by the presence of lead cations. These results suggest that the adsorption behavior of lead on this functionalized silica gel adsorbent can be directly evaluated by its lead–phosphorus interaction. This association was corroborated by the shifting of the binding energies of phosphorus functional groups after lead uptake in the XPS analysis. Full article

A nanoparticle formulation was generated from distiller dried grains with solubles (DDGS), and its effect on the production of anthraquinones (AQs) was evaluated on Rubia tinctorum hairy roots. The DDGS material was washed with water and ethyl acetate to remove mainly the soluble organic/inorganic molecules and reduce the fat content, respectively, followed by an alkaline treatment to remove the polysaccharides. The resulting alkaline solutions were then lyophilized and redispersed in deionized water to generate a monodispersed nanoparticulate formulation (DDGS-NP) with a hydrodynamic diameter and zeta potential of 227 ± 42 nm and −53 ± 7 mV, respectively. The formulation demonstrated good colloidal stability over time, and sterilized DDGS-NPs maintained comparable physicochemical properties. The nanoparticles were enriched in protein fractions, unsaturated fatty acids, and orthophosphate anion components from DDGS, as determined by solid-state Nuclear Magnetic Resonance (NMR), X-ray photoelectron spectroscopy (XPS), organic elemental analysis (OEA), and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. The DDGS-NPs were tested at different concentrations on Rubia tinctorum hairy roots, in comparison to or in combination with methyl jasmonate (MeJ), for their capacity to induce the production of AQs. All DDGS-NP concentrations increased the production of specific AQs to 7.7 (100 mg L⁻¹), 7.8 (200 mg L⁻¹), and 9.3 µmol/gFW (500 mg L⁻¹), with an extracellular AQ accumulation of 18 µM for the highest DDGS-NP concentration, in comparison with the control hairy roots (~2 µM AQ). The plant growth was not affected at any of the tested nanoparticle concentrations. Interestingly, the combination of DDGS-NPs and MeJ resulted in the highest extracellular AQ accumulation in R. tinctorum root cultures. Full article

The structures of hexaammine solvated indium(III) and thallium(III) ions in liquid ammonia solution are determined by EXAFS. Both complexes have regular octahedral coordination geometry with mean In-N and Tl-N bond distances of 2.23(1) and 2.29(2) Å, respectively. Ammine solvated thallium(III) in liquid ammonia is characterized with ²⁰⁵Tl NMR measurements. Solvents such as liquid ammonia, N,N-dimethylthioformamide (DMTF), trialkyl and triphenyl phosphite and phosphine are strong electron pair donors and thereby able to form bonds with a large covalent contribution with strong electron pair acceptors. A survey of reported structures of ammine, DMTF, trialkyl and triphenyl phosphite and phosphine solvated metal ions in the solid state and solution is presented. The M-N and M-S bond distances in ammine and DMTF solvated metal ions are compared with the M-O bond distance in the corresponding metal ion hydrates, expected to form mainly electrostatic interactions with metal ions. The d¹⁰ metal ions have high ability to form bonds with a high degree of covalency with increasing ability down the group and with decreasing charge of the metal ion. The difference in M-N and M-O bond distances between ammine solvated and hydrated metal ions with the same coordination geometry decreases significantly with the increasing ability of the metal ion to form bonds with a large covalent contribution. This difference correlates well with the covalent bonding index, γ_M²*r. Full article

The interest in macromolecular alkoxysilyl-functionalized hybrids (self-assembling or nanostructured), which could be used as precursors in biomimetic silica precipitation and for the synthesis of hollow spherical silica particles, is growing. Nevertheless, reports on all-organosilicon systems for bioinspired silica precipitation are scarce. Therefore, a new kind of polyalkoxysilane macromonomer–linear polysilsesquioxane (LPSQ) of ladder-like backbone, functionalized in side chains with trimethoxysilyl groups (LPSQ-R-Si(OMe)₃), was designed following this approach. It was obtained by photoinitiated thiol-ene addition of 3-mercaptopropyltrimethoxysilane to the vinyl-functionalized polysilsesquioxane precursor, carried out in situ in tetraethoxysilane (TEOS). The mixture of LPSQ-R-Si(OMe)₃ and TEOS (co-monomers) was used in a sol–gel process conducted under acidic conditions (0.5 M HCl/NaCl) in the presence of Pluronic^® F-127 triblock copolymer as a template. LPSQ-R-Si(OMe)₃ played a key role for the formation of microparticles of a spherical shape that were formed under the applied conditions, while their size (as low as 3–4 µm) was controlled by the stirring rate. The hybrid materials were hydrophobic and showed good thermal and oxidative stability. Introduction of zinc acetate (Zn(OAc)₂) as an additive in the sol–gel process influenced the pH of the reaction medium, which resulted in structural reinforcement of the hybrid microparticles owing to more effective condensation of silanol groups and a relative increase of the content of SiO₂. The proposed method shows directions in designing the properties of hybrid materials and can be translated to other silicon–organic polymers and oligomers that could be used to produce hollow silica particles. The established role of various factors (macromonomer structure, pH, and stirring rate) allows for the modulation of particle morphology. Full article

After reviewing the state of the art of the fluorination of inorganic solid electrolytes, an application of gas/solid fluorination is given and how it can be processed. Garnet-type oxide has been chosen. These oxides with an ideal structure of chemical formula A₃B₂(XO₄)₃ are mainly known for their magnetic and dielectric properties. Certain garnets may have a high enough Li⁺ ionic conductivity to be used as solid electrolyte of lithium ion battery. The surface of LLZO may be changed in contact with the moisture and CO₂ present in the atmosphere that results in a change of the conductivity at the interface of the solid. LiOH and/or lithium carbonate are formed at the surface of the garnet particles. In order to allow for handling and storage under normal conditions of this solid electrolyte, surface fluorination was performed using elemental fluorine. When controlled using mild conditions (temperature lower or equal to 200 °C, either in static or dynamic mode), the addition of fluorine atoms to LLZO with Li_6,4Al_0,2La₃Zr₂O₁₂ composition is limited to the surface, forming a covering layer of lithium fluoride LiF. The effect of the fluorination was evidenced by IR, Raman, and NMR spectroscopies. If present in the pristine LLZO powder, then the carbonate groups disappear. More interestingly, contrary to the pristine LLZO, the contents of these groups are drastically reduced even after storage in air up to 45 days when the powder is covered with the LiF layer. Surface fluorination could be applied to other solid electrolytes that are air sensitive. Full article

Glass curators often question how their treatments affect the long-term stability of historical glass. While damp cotton swabs are commonly used to remove surface salts and dust, the use of water remains controversial, particularly for heavily altered glass, due to concerns about worsening hydration. This study investigates the effect of water rinsing on an unstable soda-lime glass altered for six months (monoliths) and fifteen months (powders) at 35 °C and 85% relative humidity. Samples were then rinsed with Milli-Q water at 20 °C or 50 °C, and the monolithic glass was subsequently subjected to an additional 15 months of alteration under the same conditions. The glass surface was characterized by optical and scanning electron microscopy (SEM) as well as Raman spectroscopy to identify the nature of the salts. The evolution of the hydrated layer was assessed using transmission FTIR, Raman and solid-state NMR spectroscopies, ToF-SIMS, and thermogravimetric analysis (TGA). The results show that rinsing effectively removes surface salts—primarily sodium carbonate—and induces structural changes in the hydrated layer, promoting silicate network polymerization. Upon resuming alteration, rinsed monolithic samples exhibit no further degradation after the additional 15 months of alteration. These findings offer promising insights for conservation practices and may help curators refining their treatment strategies for altered glass. Full article

Searching for new and efficient transfer hydrogenation catalysts, a series of new organometallic ruthenium(II)-arene complexes of the formulae [Ru(η⁶-p-cymene)(L)Cl][PF₆] (1–8) and [Ru(η⁶-p-cymene)(L)Cl][Ru(η⁶-p-cymene)Cl₃] (9–11) were synthesized and fully characterized. These were prepared from the reaction of pyridine–quinoline and biquinoline-based ligands (L) with [Ru(η⁶-p-cymene)(μ-Cl)Cl]₂, in 1:2 and 1:1, metal (M) to ligand (L) molar ratios. Characterization includes a combination of spectroscopic methods (FT-IR, UV-Vis, multi nuclear NMR), elemental analysis and single-crystal X-ray crystallography. The pyridine–quinoline organic entities encountered, were prepared in high yield either via the thermal decarboxylation of the carboxylic acid congeners, namely 2,2′-pyridyl-quinoline-4-carboxylic acid (pqca), 8-methyl-2,2′-pyridyl-quinoline-4-carboxylic acid (8-Mepqca), 6′-methyl-2,2′-pyridyl-quinoline-4-carboxylic acid (6′-Mepqca) and 8,6′-dimethyl-2,2′-pyridyl-quinoline-4-carboxylic acid (8,6′-Me₂pqca), affording the desired ligands pq, 8-Mepq, 6′-Mepq and 8,6′-Me₂pq, or by the classical Friedländer condensation, to yield 4,6′-dimethyl-2,2′-pyridyl-quinoline (4,6′-Me₂pq) and 4-methyl-2,2′-pyridyl-quinoline (4-Mepq), respectively. The solid-state structures of complexes 1–4, 6, 8 and 9 were determined showing a distorted octahedral coordination geometry. The unit cell of 3 contains two independent molecules (Ru-3), (Ru′-3) in a 1:1 ratio, due to a slight rotation of the arene ring. All complexes catalyze the transfer hydrogenation of acetophenone, using 2-propanol as a hydrogen donor in the presence of KOiPr. Among them, complexes 1 and 5 bearing methyl groups at the 8 and 4 position of the quinoline moiety, convert acetophenone to 1-phenylethanol quantitatively, within approximately 10 min with final TOFs of 1600 h⁻¹. The catalytic performance of complexes 1–11, towards the transfer hydrogenation of p-substituted acetophenone derivatives and benzophenone, ranges from moderate to excellent. An inner-sphere mechanism has been suggested based on the detection of ruthenium(II) hydride species. Full article

The misfolding and aggregation of proteins into amyloidogenic assemblies are key features of several metabolic and neurodegenerative diseases. Human insulin has long been known to form amyloid fibrils under various conditions, which affects its bioavailability and function. Clinically, insulin aggregation at recurrent injection sites poses a challenge for diabetic patients who rely on insulin therapy. Furthermore, decreased responsiveness to insulin in type 2 diabetic (T2D) patients may lead to its overproduction and accumulation as aggregates. Earlier reports have reported that various factors such as pH, temperature, agitation, and the presence of lipids or other proteins influence insulin aggregation. Our present study aims to elucidate the effects of non–micellar anionic DMPG (1,2–dimyristoyl–sn–glycero–3–phosphoglycerol) lipids on insulin aggregation. Distinct pathways of insulin aggregation and intermediate formation were observed in the presence of DMPG using a ThT fluorescence assay. The formation of soluble intermediates alongside large insulin fibrils was observed in insulin incubated with DMPG via TEM, DLS, and NMR as opposed to insulin aggregates generated without lipids. ¹³C magic angle spinning solid–state NMR and FTIR experiments indicated that lipids do not alter the conformation of insulin fibrils but do alter the time scale of motion of aromatic and aliphatic side chains. Furthermore, the soluble intermediates were found to be more cytotoxic than fibrils generated with or without lipids. Overall, our study elucidates the importance of anionic lipids in dictating the pathways and intermediates associated with insulin aggregation. These findings could be useful in determining various approaches to avoid toxicity and enhance the effectiveness of insulin in therapeutic applications. Full article

[1,4,7,10-Tetraazacyclododecano-κ⁴N^1,4,7,10(3-)]silicon(IV) chloride was synthesized from 1,4,7,10-tetraazacyclododecane (cyclen), n-butyl lithium, and silicon tetrachloride. The crystal structure analysis reveals that this cationic compound is a dimer in the solid state with pentacoordinate silicon atoms. The compound was characterized by melting point, IR, and NMR spectroscopy. The quantum chemical analysis shows that this compound might be an interesting precursor to generate a mononuclear silicon (IV) complex with unusual reactivity due to nearly planar tetracoordinate coordination geometry at the silicon atom. Full article