The present study describes a convenient approach to cage-like coppersilsesquioxanes' extended structures using large alkaline metal (K, Rb, Cs) ions as "supramolecular facilitators". Extended family (nine examples) of Cu4-based phenylsilsesquioxane cages feature the same molecular architecture but differ principally in their supramolecular derivatives. The single-crystal X-ray diffraction analysis (SCXRD) revealed the intercage interactions due to both various alkaline metal-involved joints with solvate "linkers" (ethanol, water, acetonitrile, and acetone) and contacts between alkaline metal ions and phenyl rings of cyclic phenylsiloxanes, responsible for the generation of 1D, 2D, and 3D coordination polymers. Compound 1 was assessed as a precatalyst in the tandem oxidation of cyclohexane to ε-caprolactone. Using mCPBA as the oxidant under microwave irradiation at 80 °C for 30 min, the reaction achieved a yield of up to 31.8% of ε-caprolactone, with a high selectivity, evidencing the potential of this complex as a selective precatalyst for this one-pot process from a readily available petrochemical feedstock to a valuable industrial monomer.

Interaction of copper methylsilsesquioxane and dppm (1,1-bis(diphenylphosphino)methane) causes an intriguing redistribution of copper ions between O-and P,P-ligands. This "ligands competition" provides an unprecedented ionic complex 1 with dianionic Si16CuII12-methylsilsesquioxane cage and two external CuI3(dppm)3Cl2-cations. Cage component exhibits an unusual ability to encapsulate two species of different nature (chloride and hydroxyl). Complex 1 catalyses the one-pot peroxidative oxidation of cyclohexane to epsilon-caprolactone using mchloroperoxybenzoic acid (mCPBA) as the oxidant, without the need for an acid promoter and under mild conditions.

Introduction: Nickel oxide nanoparticles (NiO-NPs) are regarded as promising materials; however, the expansion of their applications requires detailed toxicological assessment in relevant experimental systems. In a range of models, nanostructured metal oxides have been shown to induce oxidative and inflammatory responses which, under certain conditions, may be involved in mechanisms of fibrotic remodelling. Macrophages act as early sensors of such exposures; therefore, analysing their functional response enables the characterisation of potential risks associated with NiO-NP exposure and provides a rationale for subsequent stages of safety evaluation. Research methodology: In this study, NiO-NPs were produced by a sol–gel method followed by thermal annealing at different temperatures. For further biological experiments, we selected the sample annealed at 450 °C, which exhibited the most reproducible nanoscale characteristics and was therefore considered optimal. Morphology and size parameters were assessed by electron microscopy, while phase composition and crystallite size were determined by X-ray diffraction, providing a comprehensive physicochemical characterisation of the tested material. Primary murine peritoneal macrophages were used as target cells. Cytotoxicity was evaluated using the MTT assay and morphocytological analysis, and the intensity of the cellular inflammatory response was assessed by measuring nitrite production with the Griess reagent. Results: The optimal NiO-NP sample was characterised by a predominantly nanoscale fraction and structural homogeneity, which supported its use in a cellular model for the assessment of biological effects. Exposure to NiO-NPs caused concentration-dependent impairment of macrophage viability. Marked cellular alterations were observed at high nanoparticle concentrations, whereas lower concentrations induced minimal signs of cellular damage or produced no detectable injury. In parallel, increased nitrite production was recorded, indicating activation of inflammatory mechanisms. Conclusion: Collectively, these data suggest that NiO-NPs may act as inducers of early cellular responses which, under unfavourable exposure conditions, could contribute to the development of a profibrotic tissue phenotype.

Here we present a unique high-nuclear Cu20 complex 1 prepared by a complexation of coppermethylsilsesquioxane and bathophenanthroline (bphen) ligands. X-ray diffraction studies established unprecedented structure of complex, including Cu12-based cage with Si4-cyclic and Si2-acyclic methylsilsesquioxanes. The second component of complex 1 is an unprecedented Cu8-based stairway-like fragment with each copper ion being decorated by bphen ligand. The polynuclear complex 1 catalyzes the one-pot peroxidative oxidation of cyclohexane to epsilon-caprolactone, with m-chloroperoxybenzoic (mCPBA) acid as oxidant without requiring the presence of an acid promoter, under mild conditions.

Layered double hydroxides (LDHs) are promising anion sorbents, but conventional Mg-Fe LDH synthesis requires prolonged aging. The effects of ultrasound application stage on Mg-Fe LDH microstructure and chromate uptake remain insufficiently clarified. This study compared ultrasonic treatment during and after coprecipitation and related XRD-derived microstructural descriptors to Cr(VI) sorption. Mg-Fe LDHs were synthesized using 28 or 40 kHz ultrasound during or after coprecipitation and 1.7 MHz ultrasound after coprecipitation; 24 h thermal aging was used as a reference. The products were characterized by ICP-MS, FTIR, TGA/DSC, SEM, and XRD and tested for chromate adsorption, kinetics, recyclability, multicomponent-solution performance, and soil Cr(VI) immobilization. Fifteen minutes of ultrasonication yielded Mg/Fe ≈ 2 LDHs and shortened synthesis compared with 24 h aging. Ultrasound during coprecipitation at 28 kHz gave the best sorbent, increasing experimental adsorption capacity to 80.35 mg/g versus 53.70 mg/g for the reference LDH. Sorption followed pseudo-second-order kinetics and was best described by the Freundlich model. In a multicomponent solution, this sample removed 68% Cr(VI) at 1.0 g/L and reduced water-soluble Cr(VI) in soil from 14.31 to 0.26 mg. Ultrasound application during coprecipitation improves Mg-Fe LDH structure-related characteristics and chromate sorption.

A one-pot strategy was developed for preparing a chitosan/Mg–Fe layered double hydroxide (LDH) composite by alkaline coprecipitation from an acidic chitosan solution containing Mg(II) and Fe(III) precursors, avoiding separate LDH synthesis and subsequent incorporation into chitosan. X-ray diffraction confirmed LDH formation within the chitosan matrix, and ICP analysis indicated an LDH-equivalent content of approximately 4.1 wt.% on an anhydrous basis. The composite exhibited enhanced chromate adsorption compared with both starting components. The experimental plateau adsorption capacity reached 137.4 mg/g, exceeding those of chitosan (92.2 mg/g) and Mg–Fe LDH (53.5 mg/g). Nonlinear isotherm fitting showed that Mg–Fe LDH was better described by the Freundlich model, whereas chitosan and the composite were better described by the Langmuir model. The kinetic behavior followed the pseudo-second-order equation, while Weber–Morris analysis indicated multistep uptake involving surface interaction and diffusion-related processes. In simulated groundwater containing chloride, bicarbonate, and sulfate, the composite removed 82% of Cr(VI) at 1.0 g/L. It also retained complete chromate uptake over five sorption/desorption cycles, although desorption efficiency decreased from 97.3% to 90.3%. A limitation of this study is that performance was evaluated mainly in batch systems and simplified simulated groundwater; validation with real contaminated waters and dynamic flow conditions is still required.

In this study, Rhodamine B-containing chitosan-based films were prepared and characterized using their mechanical, photophysical, and antibacterial properties. The films were synthesized using the casting method and their mechanical properties, such as tensile strength and elongation at break, were found to be dependent on the chemical composition and drying process. Infrared spectroscopy and X-ray diffraction analysis were used to examine the chemical structure and degree of structural perfection of the films. The photophysical properties of the films, including absorption spectra, fluorescence detection, emission quantum yields, and lifetimes of excited states, were studied in detail. Rhodamine B-containing films exhibited higher temperature sensitivity and showed potential as fluorescent temperature sensors in the physiological range. The antibacterial activity of the films was tested against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli, with Rhodamine B-containing films demonstrating more pronounced antibacterial activity compared to blank films. The findings suggest that the elaborated chitosan-based films, particularly those containing Rhodamine B can be of interest for further research regarding their application in various fields such as clinical practice, the food industry, and agriculture due to their mechanical, photophysical, and antibacterial properties.

Perovskite oxides (ABO3) due to their high thermal stability and the ability to control the physico-chemical properties are considered as an alternative to traditional catalysts containing noble and transition metals. Herein, the recent research breakthroughs of GdCoO3 catalysts in experimental studies are summarized in detail. First, the perovskite-type GdCoO3 complex oxides were obtained by co-precipitation method with the various precipitators and were characterized by X-ray diffraction (XRD), low temperature nitrogen adsorption and IR spectroscopy. Physical and chemical analysis showed that the choice of precipitant doesn’t significantly affect the phase composition of the perovskites. The catalytic performance of gadolinium cobaltites was discussed. It was found that the use of cobaltites obtained by co-precipitation leads to the inhibition of the side reaction of the reverse steam reforming of carbon monoxide. Finally, the investigation of the used catalysts demonstrated the formation of Gd2O2CO3 and metallic cobalt, which indicates the nature of active centres: gadolinium is the centre of CO adsorption, while hydrogen chemisorption occurs on cobalt-sites.

The first metallasilsesquioxane bearing pyrazolylpyridine ligands, the Cu8-based complex 1, adopts a cage-like structure with two zigzag-type copper tetramers sandwiched by two cyclic Si5 silsesquioxane ligands. The four 3-phenyl-5-(2-pyridyl)pyrazolate ligands in 1 exhibit dual (chelating and bridging) modes of ligation. Compound 1 is very active in the oxidation of alkanes and alcohols.

An extended (i.e., 19 distinct species) family of cage-like Cu4-phenylsilsesquioxanes allowed us to accentuate the general regularities behind their structural organization. Influencing factors, namely the (i) size of external alkali metal ions (from Li to Cs) and (ii) nature of bridging linkers (including the smallest possible ones, like a water molecule) on the self-assembly/supramolecular assembly of such Cu4-building blocks have been thoroughly explored. A Cu4K4-based complex has been evaluated as a precatalyst in the oxidation of alkanes (cyclohexane, n-heptane, methylcyclohexane) and alcohols. The experimental evidence that radical species participate in the oxidation of alkanes is provided.

We report a high nuclear (Cu14) complex synthesized via the self-assembly of copper-methylsilsesquioxane induced by the complexation with 1,2-bis(diphenylphosphino)ethane (dppe). The structure includes two cationic CuI(dppe)2 moieties and an anionic silsesquioxane cage of an unprecedented CuII12 structural type. The Cu12 cage fragment exhibits a unique (i) combination of Si4-cyclic/Si2-acyclic silsesquioxane ligands and (ii) encapsulation of two different chloride and carbonate species. This complex acts as a promising precatalyst in the mild oxidation and carboxylation of light alkanes to produce alkyl hydroperoxides, alcohols, ketones, or carboxylic acids. The present study widens the family of copper-methylsilsesquioxane clusters with prospective use in oxidation catalysis.

Unprecedented iron-based silsesquioxane/acetylacetonate complexes were synthesized. The intriguing cage-like structure of compounds is alkaline metal-dependent: the Fe2Li2 complex includes condensed Si-6-silsesquioxane and four acetylacetonate ligands; the Fe4Na4 complex exhibits two cyclic Si-4-silsesquioxane and eight acetylacetonate ligands, while the Fe3K3 complex features two cyclic Si-3-silsesquioxane and six acetylacetonate ligands. The latter case is the very first observation of small trimeric silsesquioxane ligands in the composition of cage-like metallasilsesquioxanes. The Fe4Na4-based complex exhibits a record high activity in the oxidation of inert alkanes with peroxides (55% yield of oxygenates in cyclohexane oxidation). It also acts as a catalyst in the cycloaddition of CO2 with epoxides, leading to cyclic carbonates in good yields (58-96%).

In this study, we report the synthesis of a new type of chiral crystalline organic porous salt CF2 derived from the ionic reaction between tetrakis(4-sulfophenyl)methane (TSPM) and the tetra-(S)-prolylamide of tetrakis(4-aminophenyl)methane, (S)-TPPM, and its ability to stabilize 2 nm palladium nanoparticles to give a novel, nonpyrophoric, chiral, catalytic material Pd@CF2. The preparation of the catalyst was very simple and conducted in water. The heterogeneous catalytic performance of Pd@CF2 was tested in hydrogen reductions of olefins and substituted nitroaromatic compounds using Pd/C as a comparison to determine the specific features of the novel catalyst. Although both types of catalysts exhibited similar catalytic activity in case of reductions of diphenylacetylene and nitrobenzene, Pd@CF2 predominantly promoted the reduction of p-nitrobenzaldehyde to p-aminobenzyl alcohol whereas Pd/C gave p-toluidine. The reduction of p-dinitrobenzene led to predominant formation of p-nitrophenylhydroxylamine if promoted by the novel catalyst and to a mixture of products if promoted by Pd/C. In addition, the introduction of p-alkoxy groups onto nitrobenzenes slowed down the reduction with Pd@CF2 but had no influence on Pd/C activity. A hypothesis ascribing these observations to dissimilar equilibrium distributions of nitro and polar groups within the organic framework and the palladium metal surface is proposed to rationalize the selectivity of the novel catalytic material.

The synthesis of a high nuclear (Cu9Na4) complex 1via the self-assembly of copper(ii) phenylsilsesquioxane induced by complexation with bis(triphenylphosphine)iminium chloride (PPNCl) was successfully achieved. This complex, which includes two bis(triphenylphosphine)iminium PPN+ cations, represents the first example of a metallasilsesquioxane/phosphazene compound. The Cu9Na4-silsesquioxane cage demonstrates a nontrivial combination of two pairs of Si-6-cyclic/Si-4-acyclic silsesquioxane ligands and a fusion of two Si10Cu4Na2 fragments, combined via the central ninth copper ion. The catalytic efficacy of the copper(ii) compound (1) was evaluated through the peroxidative oxidation of toluene using tert-butyl hydroperoxide (t-BuOOH) as the oxidant. The primary oxidation products were benzaldehyde (BAL), benzyl alcohol (BOL), and benzoic acid (BAC), with BAC being the predominant product, especially in acetonitrile (NCMe). The formation of cresols, indicating oxidation at the aromatic ring, was observed only in water and under microwave irradiation (MW) in NCMe. Remarkably, the highest total yield of 40.3% was achieved in water with an acidic additive at 80 degrees C, highlighting the crucial role of the acid additive in enhancing reaction efficiency and selectivity. This study underscores our copper(ii) complex as a highly effective catalyst for toluene oxidation, demonstrating its significant potential for fine-tuning reaction parameters to optimize yields and selectivity. The unprecedented structure of the complex and its promising catalytic performance pave the way for further advancements in the fields of metallasilsesquioxane chemistry and catalysis.

Self-assembly synthesis of mixed-ligand (silsesquioxane/acetate) complex allows to isolate record high nuclear copper(II) Cu13-cage (1). In the presence of two additional sodium ions, a unique molecular architecture, with triple combination of ligands (cyclic and acyclic silsesquioxanes as well as acetates), has been formed. The structure was established by single-crystal X-ray diffraction based on the use of synchrotron radiation. Complex 1 was evaluated as precatalyst in the Baeyer-Villiger oxidation of cyclohexanone towards ϵ-caprolactone, employing hydrogen peroxide, tert-butyl hydroperoxide (TBHP) or m-chloroperoxybenzoic acid (mCPBA) as oxidants, in an aqueous acidic acetonitrile medium. The direct formation of the lactone from cyclohexane via a tandem peroxidative oxidation/Baeyer-Villiger oxidation was also studied. For both substrates, the best results (ϵ-caprolactone yields up to 100 % or 26 %, from cyclohexanone or cyclohexane, respectively) were achieved with mCPBA under considerably mild conditions, i. e., conventional heating at 50 °C for 4 h or microwave (MW) irradiation at 80 °C for only 30 minutes.

In this study, new Cu(II)/chitosan-based systems were designed via (i) the treatment of chitosan with sodium sulfate (1a) or sodium acetate (1b); (ii) the coating of 1a or 2a with a sodium hyaluronate layer (2a and 2b, correspondingly); (iii) the treatment of a cholesterol–chitosan conjugate with sodium sulfate (3a) or sodium acetate (3b); and (iv) the succination of 1a and 1b to afford 4a and 4b or the succination of 2a and 2b to yield 5a and 5b. The catalytic properties of the elaborated systems in various organic transformations were evaluated. The use of copper sulfate as the source of Cu2+ ions results in the formation of nanoparticles, while the use of copper acetate leads to the generation of conventional coarse-grained powder. Cholesterol-containing systems have proven to be highly efficient catalysts for the cross-coupling reactions of different types (e.g., Sonogashira, Buchwald–Hartwig, and Chan–Lam types); succinated systems coated with a layer of hyaluronic acid are promising catalysts for the aldol reaction; systems containing inorganic copper(II) salt nanoparticles are capable of catalyzing the nitrile-oxide-to-nitrile 1,3-dipolar cycloaddition. The elaborated catalytic systems efficiently catalyze the aforementioned reactions in the greenest solvent available, i.e., water, and the processes could be conducted in air. The studied catalytic reactions proceed selectively, and the isolation of the product does not require column chromatography. The product is separated from the catalyst by simple filtration or centrifugation.

In this study, we prepared chitosan/Fe(III)/deferoxamine nanoparticles with unimodal size distribution (hydrodynamic diameter ca. 250 nm, zeta potential ca. 32 mV). The elaborated nanoparticles are characterized by outstanding in vitro and in vivo antibacterial activity, which exceeds even that of commercial antibiotics ampicillin and gentamicin. Moreover, the nanoparticles are non-toxic. We found that the introduction of iron ions into the chitosan matrix increases the ability of the resulting nanoparticles to disrupt the integrity of the membranes of microorganisms in comparison with pure chitosan. The introduction of deferoxamine into the obtained nanoparticles sharply expands their effect of destruction the bacterial membrane. The obtained antibacterial nanoparticles are promising for further preclinical studies.

In this study, we elaborated new chitosan-based films reinforced by iron(III)-containing chitosan nanoparticles Fe(III)-CS-NPs at different concentrations. We found that the optimum concentration of Fe(III)-CS-NPs for the improvement of antibacterial and mechanical properties of the films was 10% (σb = ca. 8.8 N/mm2, εb = ca. 41%, inhibition zone for S. aureus = ca. 16.8 mm and for E. coli = ca. 11.2 mm). Also, using the click-chemistry approach (thiol–ene reaction), we have synthesized a novel water-soluble cationic derivative of chitin. The addition of this derivative of chitin to the chitosan polymer matrix of the elaborated film significantly improved its mechanical (σb = ca. 11.6 N/mm2, εb = ca. 75%) and antimicrobial (inhibition zone for S. aureus = ca. 19.6 mm and for E. coli = ca. 14.2 mm) properties. The key mechanism of the antibacterial action of the obtained films is the disruption of the membranes of bacterial cells. The elaborated antibacterial films are of interest for potential biomedical and food applications.

Mild and ‘green’ ultrasound-assisted reaction of chitin with 3-(chloromethyl)[1,2,4]selenadiazolo[4,5- a ]pyridin-4-ium bromide in water affords novel selenium-containing cationic chitin derivatives. The thus obtained chitin derivatives are water soluble and are characterized by high in vitro antifungal activity comparable with conventional antifungal drug Amphotericin B.

Ciprofloxacin is one of the most effective antibiotics, but it is characterized by a range of side effects. Elaboration of drug-releasing systems which allow to diminish toxicity of ciprofloxacin is a challenging task in medicinal chemistry. The current study is focused on development of new ciprofloxacin releasing systems (CRS). We found that ultrasound efficiently promotes N,N′-dicyclohexyl carbodiimide-mediated coupling between COOH and NH2 functionalities in water. This was used for conjugation of ciprofloxacin to chitosan. The obtained ciprofloxacin/chitosan conjugates are capable of forming their self-assembled nanoparticles (SANPs) in aqueous medium. The SANPs can be additionally loaded by ciprofloxacin to form new CRS. The CRS demonstrated high loading and encapsulation efficiency and they are characterized by extended release profile (20 h). The elaborated CRS were tested in vivo in rats. The in vivo antibacterial effect of the CRS exceeded that of the starting ciprofloxacin. Moreover, the in vivo acute and subacute toxicity of the nanoparticles was almost identical to that of the chitosan, which is considered as the non-toxic biopolymer.