Di-aqua-di-isothiocyanato-tin(II)-bis(18-crown-6), Sn(NCS)2·2(18-crown-6)·2H2O – A supramolecular compound of a low-valent main group element with bent sandwich architecture

The crystal structure of the title compound, di-aqua-di-isothiocyanato-tin(II)-bis(18-crown-6), was determined by single crystal X-ray structure analysis. The compound crystallizes in the monoclinic space group C2/c with half a molecule of the point group C2 in the asymmetric unit. The supramolecular arrangement of the three different building blocks, a bent Sn(NCS)2 one, a water molecule, and an 18-crown-6 molecule exhibits a bent sandwich-like structure with an opening angle of 48.1(1)° referring to the least-squares planes through the oxygen atoms of the crown ether molecules. Bond lengths and angles within this aggregate indicate that the isothiocyanate groups bond to the central, bivalent tin atom via covalent 2e-2c-bonds based on two orthogonal p orbitals of the metal atom, and the oxygen atoms of the water molecules via a symmetrical 3c-4e bond by use of the third metal p orbital. The crown ether molecules do not have oxygen-tin contacts but are hydrogen-bonded to the water molecules. Their conformation has similarities with that of an ideal D3d conformation

Click chemistry in tuberculosis research: From drug design to therapeutic delivery - A systematic review

The molecular hybridization of 1,2,3-triazoles with various bioactive scaffolds has become a promising approach to the development of new antitubercular drugs, offering a versatile platform for improving drug efficacy and specificity. This review covers key advancements over the past decade in creating triazole-based hybrids that integrate azoles, coumarin/chromene, isoniazid, quinoline/dihydroquinoline, quinolone, ferrocene, isatin, furan, and other structures. These hybrid molecules generally show improved potency against both drug-sensitive and drug-resistant Mycobacterium tuberculosis strains while maintaining favorable toxicity profiles, making them particularly valuable in the current landscape of rising drug resistance. Structure-activity relationship (SAR) studies highlight that strategic substituent positioning and optimal linker selection are critical in enhancing antimycobacterial efficacy. Furthermore, modifications to the electronic and steric properties of the hybrids have been shown to influence their ability to bypass common resistance mechanisms, underscoring the potential of these compounds to overcome treatment barriers. In particular, several of these hybrids demonstrate promising activity against MDR-TB and XDR-TB strains, suggesting potential applications for immunocompromised patients, such as those with HIV co-infection. Collectively, these findings offer valuable insights for the rational design of next-generation antituberculosis agents that could transform tuberculosis (TB) treatment paradigms in both resistant and sensitive cases of TB

Study of solid residues obtained from the pyrolysis of commercial plastic waste bottles by FTIR and TG methods

The composition of solid residues-products of thermal pyrolysis of plastic waste (polyethylene terephthalate (PET), polypropylene (PP)) at 350-550 °C was studied by Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) methods. On the basis of the transition band (T%) the absorption and Abs parameters were calculated. It was observed that the Abs parameters of the peaks observed in the initial samples appear to change depending on the pyrolysis temperature, with the appearance of new peaks at higher temperatures. It was observed that during the pyrolysis of PET polymer waste, a number of bands with wavenumber 1692, 1670, 1262, 755, 694, and 464 cm-1 occurred at above 450 °C. It would seem that the Abs parameters for the 2923, 1453, and 846 cm-1 peaks observed in the initial samples are equal to zero. It would appear that during the pyrolysis of the PET polymer waste at 550 °C, only three peaks with wavenumbers of 1686, 1062 and 707 cm-1 are observed. Similarly, during the pyrolysis of the PP polymer waste at the same temperature, only one new peak (1092 cm-1) is observed. The solid residues of the pyrolysis processes for the samples taken at 550 °C are calculated and are equal to 13.6 and 0.6%, respectively, for PET and PP. The data shows that solid residues from the pyrolysis of PP wastes have a structure similar to that of charcoal

Enhanced photoconversion efficiency in organic polymer solar cells: Synthesis, structural analysis and computational modelling of 4,8-dichlorobenzo[1,2-b]difuran-2,6-dicarboxylic acid-based composite

Improving the photoconversion efficiency (PCE) of organic polymer-based solar cells (SCs) is crucial to their competitiveness with conventional SCs. This study presents a novel approach to improve PCE of an organic composite solar cell incorporating 4,8-dichlorobenzo[1,2-b]difuran-2,6-dicarboxylic acid. The molecular composite was designed based on the photoactive donor-π-acceptor (D-π-A) architecture and computationally modeled to optimize its efficiency. The synthesized material was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectral analysis, confirming the formation of a perovskite lattice. Photovoltaic performance was evaluated using simulated device measurements, which produced a fill factor (FF) of 0.708, a short-circuit current density (JSC) of 12.8 mA/cm2, an open-circuit voltage (VOC) of 1.22 V, and an overall PCE of 12.78%. The active exciton diffusion path length was measured at < 9 Å, with a direct band gap of 2.05 eV. The stabilized Urbach energy of the material ranged from 110 to 220 meV. Furthermore, the active single-layer film was interfaced with both a small work function electrode (SWFE) and a long work function electrode (LWFE). The material exhibited high polarizability (αtot = 483.34×10-33 esu, Δα = 332.68×10-33 esu), indicating a strong potential for efficient photoconversion. This study demonstrates the feasibility of using 4,8-dichlorobenzo [1,2-b] difuran-2,6-dicarboxylic acid-based composite for high-performance organic solar cells, offering a promising alternative to conventional SCs

Preparation and properties of physically plasticized chitosan films

Food packaging prevents conditions that can reduce food quality and shelf life. This leads to environmental pollution because it does not degrade naturally. The food packaging industry is increasingly adopting biodegradable polymer films as an alternative to plastic packaging. They are receiving great attention and are more suitable for food applications because they do not need to be eliminated as solid waste, which is why the industry has recently begun to pay more attention to food packaging films derived from natural chitosan polymers to replace traditional synthetic polymers. Shrimp cortex was used to extract the chitosan using the casting procedure; It was plasticized with different ratios of polyvinyl alcohol (PVC), namely 1:1, 1:2, 1:3, and 1:4 to create plasticized chitosan films from its solution in 2% acetic acid by casting technique. All films prepared were examined by infrared spectroscopy (FT-IR) and were found to be comparable to the original chitosan spectrum, indicating that the basic composition of the basic polymeric chitosan chains was not affected by the addition of various ratios of PVC plasticizer. Unlike unplasticized chitosan films. The results of the mechanical tensile strength measurements of plasticized chitosan films showed an improvement in tensile strength, % elongation at breakage, and a decrease in the Young modulus, which means that less rigid films were obtained, with an enhancement in their optical properties accompanying this by decreasing the opacity from 85 for unplasticized chitosan to about 3 for plasticized chitosan films. The addition of plasticizer to chitosan was also found to increase the solubility of prepared plasticized chitosan films in water and reached 100% for 1:3 chitosan:PVA in contrast to the unplasticized chitosan polymer, which is insoluble in water

Exploring the miRNA-148b and the caspase-3/Bcl-2/Bax axis as a potential predictive marker in breast cancer

Breast cancers (BCs) are the second leading cause of cancer-related deaths among women due to a lack of prediction, diagnosis, and follow-up. MicroRNAs (miRNAs) in liquid biopsies (LBs) are promising tools for the prediction and follow-up of cancer. This study aims to investigate and compare serum miRNA-148b, caspase-3, Bax, Bcl-2, and total antioxidant capacity (TAC) of BC patients with healthy controls. In this study, 300 women were included and divided into four groups of 75 each: Group 1 consisted of healthy controls, Group 2 of early-stage BC patients, Group 3 of chemotherapy-treated BC patients, and Group 4 of mastectomy-treated BC patients. Blood samples were collected for a complete blood count and serum samples were tested for miRNA-148b Bax, caspase-3, Bcl-2, and TAC. RT/PCR, ELISA and spectrophotometric methods were used to determine these parameters. In addition, histopathological examinations were performed on breast tissue samples. The present results indicated that BC patients exhibited elevated miRNA-148b, Bax, and Bcl-2 expressions compared to healthy controls. Importantly, advanced BC stages showed significantly higher miRNA-148b levels than early stages. However, levels of caspase-3 and TAC were reduced in BC patients compared to healthy controls. Histopathological analysis revealed various alterations in breast tissues, including nuclear changes, the presence of giant cells, and inflammation. The present study concluded that miRNA-148b and Bcl-2 are markedly elevated in the serum of BC patients compared to healthy subjects; however, Bax and caspase-3 levels were reduced. These findings underscore that blood miRNA-148b and caspase-3 are promising avenues for the prediction and follow-up of BC patients

An efficient synthesis, anticancer and antimycobacterial activities of new substituted pyridine based azomethine derivatives

Pyridine, a fundamental heterocyclic scaffold, is a key structural component in numerous biologically active molecules, including alkaloids, vitamins B3 and B6, coenzymes, and other natural products. Its significance in medicinal chemistry arises from its versatile physicochemical properties, such as its capacity to form hydrogen bonds, its high water solubility, and its chemical stability. In this study, a series of substituted pyridine-based analogues (3a-h) were synthesized and their structural elucidation was performed using various spectroscopic techniques. These derivatives incorporate an azomethine functionality within the pyridine core. The structural characterization of the newly synthesized compounds was achieved through spectroscopic analyses, including mass spectrometry, 1H NMR, 13C NMR, infrared (IR) spectroscopy, and complementary analytical methods such as solubility and melting point determination. The biological evaluation of the derivatives 3a-h was carried out to assess their in vitro cytotoxic activity against the human colon cancer cell line HCT-15 and the breast cancer cell line MCF-7 using the sulforhodamine B (SRB) assay. The results indicated that the synthesized compounds exhibited an anticancer activity ranging from moderate to promising. Furthermore, the compounds were subjected to preliminary antituberculosis (anti-TB) screening against Mycobacterium bovis, a representative strain of Mycobacterium tuberculosis, at varying concentrations

Synthesis of an eight-membered 2,2,4,6,6,8-hexaphenyl-1,3,5,7,2,6,4,8-tetraoxadisiladiborocane and its reaction with 4,4-azo-pyridine leading to ring contraction to give a dimer and hydrogen bonded macrocyclic siloxane-azo-pyridine

We hereby report the syntheses and characterization of a new dimer of azopyridine connected through the six-membered B-N dative-bonded-adduct Ph8B4Si2O6·L (4) and a hydrogen-bond-induced macrocyclic product 4(Ph2Si(OH)2)·3(C10H8N4) (5). The products were obtained after an eight-membered 2,2,4,6,6,8-hexaphenyl-1,3,5,7,2,6,4,8-tetraoxa disiladiborocane (Ph6B2Si2O4) (3), which is abundant in the literature, was successfully synthesized and characterized by standard analytical and spectroscopic methods such as single-crystal XRD, melting point, nuclear magnetic resonance and Fourier transform infrared spectroscopy. Subsequently, compound 3 and 4,4-azopyridine (L) were reacted in a mixture of diethyl ether and petroleum ether solvents at reflux. This reaction caused a contraction of the eight-membered compound 3 to give two products - a dimer compound 4 (Ph8B4Si2O6·L), and a macrocyclic product 4(Ph2Si(OH)2)·3(C10H8N4) (5). These two products have been characterized by single-crystal XRD, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and melting point. Single crystal X-ray diffraction studies reveal that the dimer compound 4 compound crystalized in the monoclinic crystal system with a centrosymmetric space group of P21/c, a = 11.0879(4) Å, b = 14.3707(4) Å, c = 16.2697(5) Å, β = 98.759(3)°, V = 2562.20(13) Å3, Z = 2. On the other hand, the macrocyclic product 4(Ph2Si(OH)2)·3(C10H8N4) (5) is orange blocky needles that crystallized in the triclinic crystal system with a centrosymmetric space group of P-1, a = 12.2352(3) Å, b = 15.3274(6) Å, c = 20.0271(6) Å, α = 89.879(3)°, β = 89.988(2)° γ = 78.298(3)°, V = 3677.7(2) Å3, Z = 2. Furthermore, compounds 4 and 5 exhibit various noncovalent interactions in crystal packing, such as intermolecular and intramolecular π-π as well as hydrogen bonding. This study demonstrates the potential for making novel materials via the combination of cyclodiboradisiloxane (a Lewis acid) and nitrogen-containing ligand (a Lewis base)

Theoretical insights into the structural, spectroscopic, solvent effect, reactivity, NCI, and NLO analyses of 5,7-dichloro-8-hydroxyquinoline-2-carbaldehyde

In this study, the characterization of the 5,7-dichloro-8-hydroxyquinoline-2-carbaldehyde molecule was carried out by nuclear magnetic resonance (1H and 13C NMR), Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis) spectroscopy and theoretical calculations in density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The integral equation formalism polarizable continuum (IEFPCM) solvation model was used for ethanol, dimethylsulfoxide (DMSO), and water solvents. The conformation of the molecule was analyzed, and the most stable structure was optimized, and the geometry and electronic structure of the optimized structure were examined. The chemical stability and charge transport inside the molecule were validated by the computed HOMO-LUMO band gap energies. Characteristics such as non-linear optic properties (NLO), charge analysis, and molecular electrostatic potential (MEP) aid in determining the electrophilic/nucleophilic nature. Compound intermolecular interactions were investigated by topological studies, including noncovalent interaction (NCI), reduced density gradient (RDG), electron localization function (ELF), and localized orbital locator (LOL). The natural bond order (NBO) analysis was used to examine the changes between the hyperconjugative interaction energy E(2) and the electron densities of the donor (i) and acceptor (j) bonds. The interaction energy, the NCI study, and the NBO analysis revealed that the ligand becomes stronger in the presence of a pyridine ring

Zinc oxide-catalyzed UV-photodegradation of cyhalothrin: A kinetic analysis

In this study, we present kinetic studies of the photodegradation of cyhalothrin (CyH) under ultraviolet (UV) irradiation and the photocatalytic activity of zinc oxide (ZnO) in UV-assisted photodegradation. CyH in an acetone solvent was periodically exposed to UV254 nm radiation light with a surface power density of 48 W/cm2. The photodegradation experiments were conducted by acquiring periodic wavelength-scan spectroscopic data using a double beam ultraviolet-visible (UV-vis) spectrophotometer and plotting the real-time absorbance data to monitor the reaction coordinate. Under our optimized conditions at room temperature of 26.5 °C, atmospheric pressure of 76.6 mmHg, CyH (5.0 ppm) in the 70% acetone solvent with pH = 6.8 and dose of ZnO (25 ppm) exhibited typical photodegradation efficiencies between 81.9 and 90.3 % within the first 1,200 seconds of UV irradiation. Spectroscopic data showed that the ZnO solution significantly elevated the UV-assisted photodegradation rate of CyH by about 7.03 - 7.18 times more than that of UV-only-mediated CyH photodegradation. The result confirmed and characterized the photocatalytic activity of ZnO. Under the optimized measurement conditions, the rate of the ZnO-catalyzed photodegradation of CyH was found to follow the first-order rate law (RSq. = 0.999)