Search Results (419)

Organic–inorganic hybrid crystalline materials formed in multicomponent aqueous systems are of interest because their phase behavior and physicochemical properties can be controlled by composition and crystallization conditions. In this study, the phase equilibria and crystallization behavior of the ternary aqueous Ca(ClO₃)₂·2CO(NH₂)₂–CH₂ClCOOH·(C₂H₄OH)₃N–H₂O system were investigated over the temperature range of −24 to 60 °C using the visual-polythermal method. Experimental data obtained for the two boundary binary subsystems and eight internal sections were used to construct the polythermal phase diagram. The diagram revealed distinct crystallization fields corresponding to ice, Ca(ClO₃)₂·2CO(NH₂)₂·2H₂O, CH₂ClCOOH·(C₂H₄OH)₃N, and a separate crystallization region associated with a previously unreported crystalline phase with the proposed composition ClCH₂COOH·Ca(ClO₃)₂·(C₂H₄OH)₃N. The solid phase was isolated from its crystallization region, washed with cold distilled water, dried to constant mass, and characterized by complementary Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), thermogravimetric analysis, derivative thermogravimetry, and differential scanning calorimetry (TG–DTG–DSC), and powder X-ray diffraction (PXRD). The experimentally determined Ca²⁺ and ClO₃⁻ contents were reasonably consistent with the proposed composition, while FT-IR spectroscopy revealed characteristic chlorate vibrations and changes in the vibrational environment of the organic component. SEM showed predominantly prismatic and plate-like crystalline morphologies, and EDS confirmed the presence of Ca, Cl, O, C, and N. Thermal analysis demonstrated multistage decomposition, with comparatively good thermal stability below approximately 150 °C. PXRD revealed a diffraction fingerprint distinct from those of the starting components and the corresponding physical mixture. Preliminary indexing of 19 principal reflections was consistent with a tetragonal candidate lattice with a = b = 7.7411(5) Å, c = 24.7182(10) Å, V = 1481.2(5) ų, and M₂₀ ≈ 23.0. The crystallographic analysis is considered preliminary because the diffraction profile was reconstructed from the available pattern and was not subjected to complete structure refinement. Overall, the combined phase-equilibrium, compositional, spectroscopic, morphological, thermal, and diffraction data support the isolation of a distinct organic–inorganic crystalline phase with the proposed composition. Full article

Three zinc(II) complexes based on 1-phenyl-3-methyl-4-acyl-5-pyrazolone were synthesized and characterized by elemental analysis, by X-ray crystallography and spectroscopy (UV-vis, fluorescence and IR). Crystallographic studies reveal that the complexes have a mononuclear structure in the solid state; however, intermolecular interactions combine the complexes into a 1D polymer chain. The complexes exhibit weak luminescence in the polycrystalline state and moderate emission in solutions and thin amorphous films. Thin films of the studied compounds were deposited on a glass substrate using thermal vacuum spraying, spin coating, and Langmuir-Blodgett technology and were studied using atomic force microscopy (AFM), X-ray spectroscopy, and fluorescence spectroscopy. Full article

Herein, we report an unexpected pseudo-multicomponent transformation discovered during attempts to selectively nitrate the pyridine core of 3-acetyl-2,4,6-trimethylpyridine (3). Despite employing standard nitration conditions, including KNO₃–H₂SO₄ and HNO₃–H₂SO₄ mixtures, electrophilic substitution of the aromatic ring did not occur. Instead, the reaction sequence promoted an in situ nitrozation, dehydration to nitrile oxide intermediates, and subsequent [3+2]-cycloaddition involving two substrate molecules. This process yielded a novel, highly functionalized furoxan derivative, precisely identified as 3,4-bis(2,4,6-trimethylnicotinoyl)-1,2,5-oxadiazole 2-oxide (5). The molecular architecture of compound 5 was established by ¹H and ¹³C NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction (XRD) analysis. To elucidate the stereochemical and electronic features governing compound 5, DFT calculations were performed at the ωB97X-D/6-311++G(d,p) level of theory. The experimental crystallographic disorder of the N-oxide oxygen atom was computationally rationalized by the thermodynamic near-degeneracy (ΔG < 0.63 kcal/mol) of two orientational isomers (5a and 5b). Furthermore, frontier molecular orbital analysis within the framework of perturbation theory accounted for the head-to-tail regioselectivity during cyclization, while wide energy gaps (ΔE = 8.13–8.27 eV) and high chemical hardness (η = 4.07–4.14 eV) underscored the kinetic stability of the heterocycle. Phenotypic and target-specific in silico profiling using PASS Online identified Matrix Metalloproteinase-9 (MMP-9) as a relevant target for potential hemorheological and cardioprotective applications. Validated molecular docking simulations across three human MMP-9 crystallographic domains (PDB: 8K5Y, 6ESM, 4XCT) demonstrated competitive binding affinities and balanced Ligand Efficiency metrics (LE = 0.26–0.29 kcal/mol/heavy atom), anchoring compound 5 within the catalytic pocket via conventional hydrogen bonds and π-mediated interactions. Finally, in vitro evaluations using a blood hyperviscosity model confirmed significant hemorheological efficacy, as compound 5 effectively prevented the rise in blood viscosity, outperforming the reference drug pentoxifylline. The convergence of computational insights and experimental functional activity establishes this novel bis(nicotinoyl)furoxan framework as a promising candidate for further hemorheological and cardioprotective applications. Full article

Powder X-ray diffraction (XRD) was used to determine the crystal structure of sodium chloride (NaCl) powder and to evaluate the accuracy with which a simple laboratory diffraction dataset can recover the crystallographic parameters of a well-known ionic solid. The diffraction profile collected over the angular interval 20° ≤ 2θ ≤ 90° contains nine indexed reflections at approximately 27.4°, 31.7°, 45.5°, 53.9°, 56.5°, 66.3°, 73.1°, 75.4°, and 84.1°. The sequence of squared-sine ratios, when referenced to the first reflection, is consistent with the allowed reflections of a face-centered cubic lattice. The observed indexing sequence is assigned to the (111), (200), (220), (311), (222), (400), (331), (420), and (422) reflections of the rock-salt structure. From Bragg analysis and the cubic interplanar-spacing relation, the average lattice parameter was determined as a = 5.642 ± 0.004 Å, in excellent agreement with the accepted value of approximately 5.640 Å for NaCl at ambient conditions. Peak broadening was further used to estimate an apparent Scherrer crystallite size of about 41.6 nm. This value should be interpreted as an XRD coherence length rather than as a direct particle size, because instrumental broadening and microstrain were not independently deconvoluted. A structure-factor and Lorentz–polarization analysis was used to rationalize the intensity hierarchy of the diffraction peaks and to explain why odd allowed reflections are weak but observable in NaCl owing to the difference between the Na⁺ and Cl⁻ scattering factors. The contribution of this work is methodological and educational: it reconstructs a transparent workflow connecting peak fitting, indexing, lattice-constant evaluation, crystallite-size estimation, and intensity interpretation within one coherent analysis. The incorporation of data-driven whole-pattern analysis significantly enhances structural validation, providing improved accuracy in lattice-parameter determination and a more reliable interpretation of crystallite size and microstrain effects. Full article

In the present work, graphene-modified zinc oxide (ZnO-rGO) and fluorine-doped tin oxide (FTO) thin films were successfully fabricated using a simple, low-cost pulsed spray pyrolysis technique. The structural, morphological, optical, electrical, and surface electronic properties of the deposited films were systematically characterized. X-ray diffraction (XRD) analysis confirmed the formation of polycrystalline ZnO- and SnO₂-based phases with crystallite sizes in the nanometer range. The crystallographic parameters, microstrain, and dislocation density of the deposited films were found to be influenced by the incorporation of reduced graphene oxide (rGO) and fluorine dopants. Scanning electron microscopy (SEM) revealed compact and homogeneous surface morphologies with good film coverage and well-defined nanocrystalline features. Optical characterization demonstrated the wide-bandgap semiconducting behavior of the deposited films, with optical bandgap energies ranging from 3.262 to 3.312 eV for the ZnO-rGO films and from 3.91 to 4.01 eV for the FTO films. Kelvin probe measurements yielded work-function values in the range of approximately 5.0–5.2 eV, indicating favorable surface electronic characteristics suitable for optoelectronic applications. Furthermore, fluorine incorporation enhanced the dielectric response of the SnO₂ films, particularly in the low-frequency region owing to increased interfacial polarization effects. The obtained results demonstrate that pulsed spray pyrolysis provides a simple, cost-effective, and efficient route for fabricating ZnO-rGO and FTO thin films with desirable structural, optical, electrical, and surface electronic properties. These findings highlight the considerable potential of the developed materials for transparent electrodes and a wide range of optoelectronic applications. Full article

The condensation reaction of pyromellitic dianhydride and (aminomethyl)phosphonic acid in imidazole yielded N,N′-bis(phosphonomethyl)pyromellitimide ([(H₂O₃P)CH₂-(C₁₀H₂N₂O₄)-CH₂(PO₃H₂)]∙2H₂O). Recrystallization of this compound from deionized water, by placing the solution in a desiccator to allow slow diffusion of HCl, afforded suitable single crystals for X-ray crystallographic studies. The compound crystallizes in the monoclinic space group P2₁/n. The flexible methylene phosphonic acid groups appended to both nitrogen termini adopt a trans configuration. The phosphonate and carbonyl groups (acceptors: P=O and C=O), together with water molecules [donor: O(6)—H∙∙∙O], participate in an extensive network of hydrogen-bonding interactions. Two of the phosphonate groups are protonated as P—OH (donors) and interact with oxygen atoms of neighboring phosphonate groups and water molecules. Hirshfeld surface analysis and associated two-dimensional fingerprint plots indicate that O∙∙∙H/H∙∙∙O (56.1%) contacts are the primary contributors to the crystal packing, followed by H∙∙∙H (16.3%) and C∙∙∙O/O∙∙∙C (13.4%) interactions. No significant π–π interactions were observed. The direct optical bandgap value, estimated from the Tauc plot, is 3.24 eV, indicating semiconducting behavior. The compound also exhibits thermal stability up to ~270 °C. These properties suggest that this compound may be a promising candidate for future investigation in organic electronic and optoelectronic materials. Full article

Powder X-ray diffraction was used to validate the crystal structure of iron metal powder and to demonstrate a transparent workflow for extracting crystallographic and microstructural information from a simple laboratory dataset. The diffraction profile collected over the angular range of approximately 36° to 95° contains three dominant reflections located at 2θ = 44.850°, 65.218°, and 82.540°. Conversion of the peak positions into d-spacings using Bragg’s law gives values of approximately 2.020 Å, 1.430 Å, and 1.170 Å. The squared-sine ratios, when referenced to the first reflection, follow the sequence of 1:2:3, which is characteristic of the allowed reflections of a body-centered cubic lattice when multiplied by the first allowed value of N = h² + k² + l² = 2. Therefore, the peaks are assigned to the (110), (200), and (211) reflections of α-Fe. The extracted lattice constants are 2.853, 2.860, and 2.865 Å, yielding an average value of 2.859 Å, which is close to the accepted room-temperature value of approximately 2.866 Å for α-Fe. Peak-width calculations based on the observed, instrument-uncorrected FWHM values are included only as illustrative apparent line-broadening indicators. Because an external instrumental standard was not measured under identical conditions, no quantitative coherent-domain size or microstrain is claimed. The Williamson–Hall treatment is therefore used only to demonstrate the sensitivity of size-strain interpretation to peak breadth, profile selection, and the limited number of available reflections. The intensity hierarchy was analyzed using the body-centered cubic-structure factor, reflection multiplicity, Fe atomic form factor, and Lorentz polarization correction. The comparison between calculated and experimental intensities shows stronger disagreement than the lattice-parameter analysis, illustrating the greater sensitivity of intensity analysis to preferred orientation, specimen preparation, peak-profile selection, and background treatment. The work provides a publication-style reconstruction of an iron powder XRD experiment, connecting peak fitting, indexing, lattice-parameter determination, crystallite size estimation, size-strain analysis, and intensity interpretation in a single critical framework. Full article

The increasing generation of agricultural and industrial waste has created a growing need for sustainable materials that can reduce environmental burdens while maintaining desirable performance. This study explores the development of hybrid composites using pinecone waste and cottonseed waste generated during spinning operations as reinforcement materials in epoxy and PCL (polycaprolactone) matrices. Four composite formulations were produced and evaluated in terms of their physical, mechanical, thermal, morphological, and crystallographic characteristics. Density, water absorption, tensile, compressive, flexural, and thermal conductivity properties were measured using standard testing procedures. Surface morphology and fiber–matrix interactions were examined through scanning electron microscopy (SEM), while X-ray diffraction (XRD) was used to investigate the crystalline structure of the composites. The epoxy-based formulations exhibited superior tensile and flexural performance, reduced moisture uptake, and lower thermal conductivity, indicating their suitability for interior and semi-structural applications. In comparison, the PCL-based composites demonstrated higher compressive load resistance and greater deformation capability, suggesting potential use in biodegradable packaging and cushioning materials. SEM analysis revealed noticeable differences in filler distribution and interfacial characteristics among the formulations, whereas XRD confirmed the crystalline features associated with both the polymer matrices and lignocellulosic reinforcements. Overall, the results demonstrate a practical route for converting forestry residues and spinning-industry waste into functional composite materials, supporting waste valorization and resource-efficient material development. Full article

The calcareous tubes of the annelid worm Ditrupa are known from the Eocene to present-day marine settings. It has a distinctive and unique outer layer comprising regularly ridged prismatic fabric (RRP), and a more chaotic inner layer of semi-oriented, needle-to-thread-like calcite, simple preferentially orientated prismatic (SPOP) fabric. We use electron backscattered diffraction (EBSD) analysis in conjunction with scanning electron microscopy (SEM) backscattered (BSE) imaging and energy dispersive X-ray (EDX) mapping in the study of the tube structure of (?)Eocene Ditrupa sp. The fabric of both layers can often be observed even within the older fossil materials. EBSD Inverse Pole Figures and pole figure plots show that the crystallographic c-axis is orientated parallel to both of the elongate calcite crystals of the two fabric layers, although orientation between the two layers is perpendicular to each other. The crystals and c-axis of the RRP fabric is approximately perpendicular to the outer tube margin, while those in the SPOP fabric are more distributed with an orientation parallel to the tube circumference. The current work confirms the single crystal origin of RRP fabric crystals and indicates that these grew incrementally and were likely controlled by an organic framework. The inner layer fabric is also shown to be unique to Ditrupa, and although it has elements similar to lamello-fibrillar (LF) and irregular orientated prismatic (IOP) fabrics, should be assigned to simple preferentially orientated prismatic (SPOP) fabric previously noted from Ditrupa bartonensis. Given the range of unusual features associated with the latter fabric, it may also at least in part be controlled through an in situ organic framework. Therefore, both layers of the tube of Ditrupa may be unique amongst the annelids, as well as being organic framework controlled or influenced. Full article

Allobetulin 3-benzoate was obtained as an unexpected byproduct during the acid-mediated protection–deprotection of betulin. Single-crystal X-ray diffraction analysis shows that it crystallizes in the triclinic space group P1 with Z = 2 and contains two crystallographically independent molecules in the asymmetric unit. Compared with allobetulin (P2₁, Z = 4) and allobetulin 3-acetate (C2, Z = 4), the benzoyl substitution at C-3 induces distinct molecular packing and intermolecular interaction patterns, highlighting the influence of steric and electronic effects on crystal architecture. Full article

This study investigates potassium-L zeolite (K-L) as an adsorbent for the removal of thallium (Tl⁺) from aqueous solutions, focusing on the relationship between cation exchange and framework structural response. X-ray powder diffraction (XRPD), thermal analysis, and Rietveld refinements were employed to monitor structural modifications upon Tl⁺ uptake, combined with batch adsorption experiments to evaluate the removal performance. At low Tl⁺ uptake, only minor structural perturbations occur, mainly involving slight shifts in extra-framework cation positions and limited rearrangement of channel water molecules. At higher Tl⁺ concentrations, a measurable anisotropic expansion of the zeolite framework is observed, consistent with partial substitution of K⁺ by Tl⁺ and progressive modification of the hydration environment within the pores. Moreover, the crystallographic distribution of Tl⁺ differs from that of the original K⁺ cations, suggesting a specific site preference during the uptake process. Batch experiments reveal rapid uptake kinetics, with equilibrium reached within minutes, and high removal efficiency up to 99.5%. The adsorption behaviour is well described by the Langmuir model, with a maximum adsorption capacity of 631 mg g⁻¹. These findings highlight the coupling between ion exchange and structural flexibility in K-L zeolite and support its potential application for efficient thallium removal from contaminated water. Full article

New lacunary Keggin-type polyoxometalate salts with the formula Cs₅PMMo₁₁(H₂O)O₃₉ (M = Cu, Zn) were synthesized via the inorganic solution condensation method. X-ray diffraction and FT-IR spectroscopy confirmed the preservation of the Keggin structure. The surface morphology and elemental composition were characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. Thermal analysis, performed by differential scanning calorimetry coupled with thermogravimetry, demonstrated a significant enhancement in thermal stability upon the incorporation of the transition metals into the heteropolyacid framework. Specifically, the substitution of protons by cesium and of molybdenum by copper or zinc positively influenced the crystallographic configuration of the salts, raising their thermal resistance (up to 526 °C). Furthermore, optical and dielectric measurements revealed promising electronic properties in the synthesized lacunary salts. Notably, the compound Cs₅PZnMo₁₁(H₂O)O₃₉ exhibited a substantially increased dielectric constant at low frequency, underscoring the synergistic effect of zinc addition on its dielectric performance. Full article

4-Methyl-N-(4-methylbenzyl)-N’-(4-methylbenzylidene)benzenesulfonohydrazide was synthesized via N-alkylation. The compound was characterized by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Its molecular structure was unambiguously established by single-crystal X-ray diffraction analysis. The comprehensive spectral and crystallographic data conclusively verify the successful synthesis and structural integrity of this newly prepared compound. Full article

The Al-bearing scorodite from the Hemerdon Ball Mine (HBM) was studied using electron microscopy and microprobe analysis, single-crystal X-ray diffraction, infrared, and Raman spectroscopy. The crystal chemistry formula of Al-bearing scorodite is expressed as Fe³⁺_0.87Al³⁺_0.16(As_0.97O₄)·H₂O. The calculated d-spacings and unit-cell parameters of Al-bearing scorodite are slightly affected by the substitution of Al for Fe in the octahedral sites. The Al-bearing scorodite HBM crystalizes in the Pbca space group with the following unit-cell lattice parameters: a = 8.92882(14) Å; b = 10.02217(14) Å; c = 10.30525(15) Å; V(Å) = 922.18(2) and Z = 8. The lattice structure becomes slightly distorted by the formation of the Fe,Al-OH octahedron, which leads to a compression of the newly formed octahedron along the a* ^ b* direction and an expansion of the Fe-OH octahedron along the c* direction. The incorporation of Al³⁺ has a strong effect on the tilting angle of the Fe,Al-OH octahedron in the b* ^ c* crystallographic direction. The refined structure suggests that Al³⁺ occupies the octahedral sites alongside Fe³⁺, leading to a distortion of the Fe,Al-OH octahedron. Infrared and Raman spectroscopy exhibit a doublet at 820 and 800 cm⁻¹, and at 810 and 800 cm⁻¹ ascribed to the Fe,Al-O-OAsO₃ group. The 799–800 cm⁻¹ Raman region is assigned to the Fe–O–As group (at 798 and 803 cm⁻¹), whereas the 810–814 cm⁻¹ region is ascribed to a band resulting from the AsO₄³⁻ [υ₁ (A₁) symmetric stretching vibrational modes], indicative of the Fe,Al–OH–As group in both Al-bearing scorodite and mansfieldite. Full article

Research on oxazolones, particularly 4-alkynyloxazolones, has garnered increasing interest due to the presence of an alkynyl group, which facilitates molecular conjugation and enables diverse chemical modifications. In this study, three representative 4-alkynyloxazolone derivatives (L1–L3) were synthesized and structurally characterized through single-crystal X-ray diffraction and computational analysis to obtain a reliable structure of L1–L3 to subsequently predict in silico interactions with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein. The crystallographic results revealed high molecular planarity and multifurcated hydrogen bonding. Considering the obtained crystallographic structure, theoretical descriptors such as HOMO–LUMO energy gaps and electrostatic potential maps indicated that these compounds exhibit favorable electronic reactivity, particularly for L3, with favorable drug-like predictions. The lack of methoxy groups in L2 and L3 makes these compounds have lower predicted toxicity parameters than L1. Molecular docking calculations targeting SARS-CoV-2 spike glycoprotein in three different feasible conformations in a biological matrix, i.e., three receptor-binding domains (RBD) in down conformation, two RBD in down and one in up conformation, as well as RBD bound to the human receptor angiotensin-converting enzyme 2 (ACE2), suggested strong binding affinities and specific interactions with the RBD moiety, mainly in the up conformation. Overall, this work integrates crystallographic and computational approaches to establish the structural and in silico evaluation of spike-binding properties of early substituted 4-alkynyloxazolones, suggesting L3 as a candidate for future in vitro antiviral assays. Full article