Inorganics

20 pages, 4378 KB

Open AccessArticle

Structural and Magneto-Optical Study on the Tetrahedrally Configured [CoCl₂(1-allylimidazole)₂] and Molecular Docking to Hypoxia-Inducible Factor-1α

by Hela Ferjani, Bruno Poti e Silva, Faizul Azam, Yasmeen G. Abou El-Reash, Tarek Yousef, Nahal Rouzbeh, Leonhard Rochels, Sabrina Disch, Sascha A. Schäfer and Axel Klein

Inorganics 2025, 13(11), 344; https://doi.org/10.3390/inorganics13110344 (registering DOI) - 23 Oct 2025

Abstract

The Co(II) complex [CoCl₂(AImd)₂] (AImd = 1-allylimidazole) was reinvestigated using a combination of experimental and theoretical methods. The previously reported crystal structure was redetermined and Hirshfeld surface analysis and enrichment ratios were added showing that intermolecular H⋯Cl and π⋯π interactions are the primary forces in the crystal structure, while H⋯H interactions dominate the surface of the molecule, making it rather hydrophobic in keeping with a low solubility in water. A Quantum Theory of Atoms in Molecules (QTAIM)/Non-Covalent Interactions (NCI)-Reduced Density Gradient (RDG) analysis on a dimeric model showed that the energies V(r) of the classical H⋯Cl hydrogen bonds range from −3.64 kcal/mol to −0.75 kcal/mol and were augmented by hydrophobic H⋯C interactions of >1 kcal/mol. T-dependent magnetization measurements reveal paramagnetic behavior with an effective magnetic moment of µ_eff = 4.66(2) µ_B. UV-vis absorption spectra in solution showed intense absorptions peaking at 240 nm, corresponding to intraligand π→π* transitions within the 1-allylimidazole moiety and a structured absorption around 600 nm, which is attributed to the spin-allowed d→d transitions of the high-spin Co(II) d⁷ ion in a distorted tetrahedral geometry. Both assignments were confirmed through TD-DFT calculations on the electronic transitions and agree with the DFT-calculated compositions of the frontier molecular orbitals. Molecular docking to hypoxia-inducible factor-1 alpha (HIF-1α) gave a docking score of −5.48 kcal/mol and showed hydrophobic⋯hydrophobic π-stacking interactions with the Ile233, Leu243, Val338, and Leu262 residues. A higher docking score of −6.11 kcal/mol and predominant hydrophobic⋯hydrophobic interactions with Trp296, His279, and Ile281 were found for HIF-1 inhibiting factor (FIH-1). Full article

(This article belongs to the Special Issue Coordination and Organometallic Chemistry for Catalytic and Biomedical Applications)

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11 pages, 2803 KB

Open AccessArticle

Correlation of EPR and Photoluminescence Analysis for Crystalline Defects in Eu³⁺/Yb³⁺-Doped Lutetium Silicate Sol–Gel Powders

by Andrea Danielle Cancino-Moreno, Arturo López-Marure, Stephany Natasha Arellano-Ahumada, Daniel Ramírez-Rosales and Margarita García-Hernández

Inorganics 2025, 13(11), 343; https://doi.org/10.3390/inorganics13110343 - 22 Oct 2025

Abstract

Crystalline defects such as oxygen vacancies have been studied little by electron paramagnetic resonance (EPR) spectroscopy for silicate-based luminescent materials. In this study, lutetium oxyorthosilicate powders were prepared by the sol–gel method, using TEOS (silicon source) and rare earth salts as precursors. The cross-linking agent, Glymo, contributed silicon atoms to the precursor solution in all systems. The addition of Glymo to Lu₂SiO₅, Lu₂SiO₅:Eu and Lu₂SiO₅:Eu/Yb influenced the morphology and chemical structure of the powders, leading to Lu₂Si₂O₇ formation. The crystalline defects in the lutetium silicate systems were investigated by EPR spectroscopy, and several defects related to oxygen were identified, as well as impurities from the precursors. Photoluminescence emission spectra revealed Eu³⁺ transitions between ⁵D₀ → ⁷F₀, ⁵D₀ → ⁷F₁ and ⁵D₀ → ⁷F₂ under 258 nm excitation, in addition to oxygen vacancy emissions between 500 and 550 nm. Oxygen vacancies were identified and confirmed by correlating EPR and photoluminescence studies. Full article

(This article belongs to the Special Issue Phosphors: Synthesis, Properties, and Structures)

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20 pages, 6093 KB

Open AccessArticle

An Integrative Biosynthetic Approach to Silver Nanoparticles: Optimization Modeling, and Antimicrobial Assessment

by Emad Abada, Mukul Sharma, Asmaa A. Alharbi, Shifaa O. Alshammari, Amani Alhejely, Yosra Modafer, Wail Alsolami, Ibrahim Y. Y. Sumaily and Mari Sumayli

Inorganics 2025, 13(11), 342; https://doi.org/10.3390/inorganics13110342 - 22 Oct 2025

Abstract

Silver nanoparticles (AgNPs) are valued for their antimicrobial properties, but conventional synthesis often involves toxic chemicals. Eco-friendly biosynthesis using silver-tolerant microbes from contaminated sites offers a sustainable alternative. This study biosynthesized and characterized AgNPs using a native Bacillus sp. from contaminated soil in the Jazan region, Saudi Arabia, and developed predictive models for optimizing synthesis and antimicrobial activity. AgNPs were synthesized under optimized conditions (1.0 mM AgNO₃, 4.0 mL supernatant, pH 8, 85 °C). Characterization using UV–Vis, SEM, TEM, XRD, and FTIR assessed size, shape, structure, and chemistry. Gaussian and second models evaluated yield and inhibition zones based on AgNP concentration, microorganism type, and MIC. The AgNPs were spherical with diameters of 5–10 nm. The optimal nanoparticle yield occurs when the parameters are at their optimal values; C₀ = 1.0 mM, V₀ = 4.0 mL, pH₀ = 8, T₀ = 85 °C. XRD confirmed their crystalline nature, and FTIR showed biomolecular capping agents for stabilization. The Gaussian model accurately predicted synthesis efficiency, validated by 3D plots matching experimental data. The AgNPs showed strong antimicrobial activity against Gram-positive (Bacillus subtilis) (ATCC6051), Staphylococcus aureus (ATCC12600), Gram-negative bacteria Escherichia coli (ATCC11775) and fungi Candida albicans (ATCC10231); with E. coli having the lowest MIC (1.87 μg/mL). The inhibition zone model closely matched observed data. Biosynthesized AgNPs using silver-tolerant Bacillus sp. demonstrated potent antimicrobial effects and provide a green alternative to chemical synthesis. Integrating modeling optimizes biosynthesis and predicts biological performance, supporting future nanobiotechnology and antimicrobial applications. Full article

(This article belongs to the Special Issue Advances in Metallic Nanoparticles for Antibacterial and Antibiofilm Control)

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Inorganics, Volume 13, Issue 11 (November 2025) – 3 articles

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