Inorganics

11 pages, 1102 KB

Open AccessArticle

Pulsed EPR Study of the Interaction Between ²³Na⁺ and Flavin in the Sodium-Pumping NADH:Ubiquinone Oxidoreductase (NQR) from Vibrio cholerae

by Sergei A. Dikanov and Robert B. Gennis

Inorganics 2026, 14(1), 31; https://doi.org/10.3390/inorganics14010031 - 20 Jan 2026

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Abstract

Sodium-pumping NADH: ubiquinone oxidoreductase (Na⁺-NQR) is an important component of the aerobic respiratory chain of Vibrio cholerae. It oxidizes NADH, reduces ubiquinone, and uses the free energy of this redox reaction to move sodium across the cell membrane. The enzyme [...] Read more.

Sodium-pumping NADH: ubiquinone oxidoreductase (Na⁺-NQR) is an important component of the aerobic respiratory chain of Vibrio cholerae. It oxidizes NADH, reduces ubiquinone, and uses the free energy of this redox reaction to move sodium across the cell membrane. The enzyme is a membrane complex of six subunits, two 2Fe−2S centers, and four flavins. Both the oxidized and reduced forms of Na⁺-NQR exhibit EPR signals due to flavin semiquinone radicals. It has been shown that in the oxidized form of the enzyme, the radical is a neutral flavin, while in the NADH-reduced form, the radical is an anionic flavin. Electron Spin Echo Envelope Modulation Spectroscopy (ESEEM) was used to probe the presence of the magnetic nucleus ²³Na in the immediate vicinity of the paramagnetic centers. The contribution of the ²³Na nucleus was observed only in the ESEEM spectra of the anionic flavin semiquinone previously assigned to FMN_NqrB. Analysis shows that the Na⁺ ion is within ~3–4 Å of the flavin radical. This distance is consistent with two models: (i) complexation of the Na⁺ ion with the carbonyl group of CO4; or alternatively, (ii) a “cation-π interaction,” between Na⁺ and the electron-rich π-system of the flavin aromatic rings. Full article

(This article belongs to the Special Issue Feature Papers in Bioinorganic Chemistry 2026)

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13 pages, 4761 KB

Open AccessArticle

Low Molecular Weight Acid-Modified Aluminum Nitride Powders for Enhanced Hydrolysis Resistance

by Linguang Wu, Yaling Yu, Shaomin Lin, Xianxue Li, Chenyang Zhang and Ji Luo

Inorganics 2026, 14(1), 30; https://doi.org/10.3390/inorganics14010030 - 18 Jan 2026

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Abstract

Aluminum nitride (AlN) possesses an exceptional combination of high thermal conductivity and an ultra-wide band gap, rendering it highly attractive for electronic packaging and semiconductor substrate applications. In this study, surface chemical modification of AlN powders was performed employing low-molecular-weight organic acids, successfully [...] Read more.

Aluminum nitride (AlN) possesses an exceptional combination of high thermal conductivity and an ultra-wide band gap, rendering it highly attractive for electronic packaging and semiconductor substrate applications. In this study, surface chemical modification of AlN powders was performed employing low-molecular-weight organic acids, successfully yielding hydrolysis-resistant AlN powders. The underlying mechanisms responsible for the improved anti-hydrolysis performance imparted by both single organic acids and the composite acid were systematically investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM), characterization techniques. The results reveal that Oxalic acid within the concentration range of 0.25 M to 1.50 M partially inhibits the hydrolysis of aluminum nitride (AlN); however, hydrolysis products such as aluminum hydroxide are still formed. In the case of citric acid, a higher concentration leads to a stronger anti-hydrolysis effect on the modified AlN. No significant hydrolysis products were detected when the AlN sample was treated in a 1 M aqueous citric acid solution at 80 °C. The effectiveness of the organic acids in enhancing the hydrolysis resistance of AlN follows the order: composite acid (citric acid + oxalic acid) > citric acid > oxalic acid. Under the action of the composite acid, the AlN diffraction peaks exhibit the highest intensity. Furthermore, TEM observations reveal the formation of an amorphous protective layer on the surface, which contributes to the improved hydrolysis resistance. Analytical results confirmed that the surface modification process, mediated by citric acid, oxalic acid, or the composite acid, involved an esterification-like reaction between the surface hydroxyl groups on AlN and the chemical modifiers. This reaction led to the formation of a continuous protective coordination layer encapsulating the AlN particles, which serves as an effective diffusion barrier against water molecules, thereby significantly inhibiting the hydrolysis reaction. Full article

(This article belongs to the Section Inorganic Materials)

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13 pages, 2628 KB

Open AccessArticle

Electrical Properties and Charge Transfer Mechanisms in Nanoscale Anodic TiO₂ Films at Low Applied Voltages

by Vyacheslav A. Moshnikov, Ekaterina N. Muratova, Igor A. Vrublevsky, Alexandr I. Maximov, Andrey A. Ryabko, Alena Yu. Gagarina and Dmitry A. Kozodaev

Inorganics 2026, 14(1), 29; https://doi.org/10.3390/inorganics14010029 - 17 Jan 2026

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Abstract

The current–voltage characteristics (IVCs) of anodic TiO₂ films in a thin-film structure (Carbon paste/TiO₂/Ti/Al) were investigated in the temperature range of T = 80–300 K with bias voltages from −0.5 V to +0.5 V. Anodic oxide film, with a thickness [...] Read more.

The current–voltage characteristics (IVCs) of anodic TiO₂ films in a thin-film structure (Carbon paste/TiO₂/Ti/Al) were investigated in the temperature range of T = 80–300 K with bias voltages from −0.5 V to +0.5 V. Anodic oxide film, with a thickness of 14 nm, was obtained by electrochemical oxidation of Ti at a voltage of 10 V. The obtained data for various temperatures showed that the IVCs in the forward (negative on the Ti electrode) and reverse (positive on the Ti electrode) bias of the thin film structure are not symmetrical. Based on the analysis, three temperature ranges (sections) were identified in which the IVCs differ in their behavior. Examination of the IVCs revealed that the conductivity mechanism in Section I (temperature range from 298 to 263 K) is determined by the Space Charge Limited Current (SCLC). Section II, in the temperature range from 243 to 203 K, is characterized by the onset of conductivity involving donor centers, in the case where the concentration of electrons on traps is significantly higher than the concentration of electrons in the conduction band. In Section III, within the temperature range from 183 to 90 K, the conduction mechanism is the Poole–Frenkel process involving donor centers. These donor centers are located below the level of traps in the forbidden band. The results obtained indicate that anodic TiO₂ is an n-type semiconductor, in the bandgap of which there are both electron traps and donor centers formed by anionic (oxygen) vacancies. The different behavior of the characteristic energy with different sample biasing in the case of the Poole–Frenkel mechanism indicates a two-layer structure of anodic TiO₂. Full article

(This article belongs to the Special Issue Advanced Inorganic Nanomaterials for Energy Conversion and Catalysis Applications, 2nd Edition)

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16 pages, 3760 KB

Open AccessArticle

A DFT Study on Sc-Catalyzed Diastereoselective Cyclization of 2-Picoline with 1,5-Hexadiene: Mechanism and Origins of Regio- and Stereoselectivity

by Guangli Zhou, Shuangxin Zhai, Xia Leng, Yunzhi Li, Qiying Xia and Yi Luo

Inorganics 2026, 14(1), 28; https://doi.org/10.3390/inorganics14010028 - 16 Jan 2026

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Abstract

Density functional theory (DFT) calculations elucidate the mechanism of diastereoselective cyclization of 2-picoline with 1,5-hexadiene catalyzed by a cationic half-sandwich scandium complex. The catalytic cycle proceeds through four key stages: formation of active species, initial alkene insertion, cis-selective cyclization, and protonation. Central [...] Read more.

Density functional theory (DFT) calculations elucidate the mechanism of diastereoselective cyclization of 2-picoline with 1,5-hexadiene catalyzed by a cationic half-sandwich scandium complex. The catalytic cycle proceeds through four key stages: formation of active species, initial alkene insertion, cis-selective cyclization, and protonation. Central to the mechanism is the dual role of 2-picoline, which initially coordinates as a supporting ligand to facilitate C–H activation and regioselective 1,2-insertion but must dissociate to enable stereocontrol. The mono(2-picoline)-coordinated complex C3 is identified as the thermodynamically favored active species. C–H activation reactivity follows the trend: ortho-C(sp²)–H (2-picoline-free) > ortho-C(sp²)–H (2-picoline-coordinated) > benzylic C(sp³)–H (2-picoline-free) > benzylic C(sp³)–H (2-picoline-coordinated), a preference governed by a wider C_α–Sc–C_α′ angle and shorter Sc···X (X = C_α, C_α′, H) distances that enhance scandium–substrate interaction. Subsequent 1,5-hexadiene insertion proceeds with high 1,2-regioselectivity through a picoline-assisted pathway. The stereoselectivity-determining step reveals a mechanistic dichotomy: while picoline coordination is essential for initial activation, its dissociation is required for intramolecular cyclization. This ligand displacement avoids prohibitive steric repulsion in the transition state, directing the reaction exclusively toward the cis-cyclized product. The cycle concludes with a sterically accessible mono-coordinated protonation. This work establishes a “ligand-enabled then ligand-displaced” mechanism, highlighting dynamic substrate coordination as a critical design principle for achieving high selectivity in rare-earth-catalyzed C–H functionalization. Full article

(This article belongs to the Section Coordination Chemistry)

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12 pages, 3283 KB

Open AccessArticle

Amidine-Linked Closo-Dodecaborate–Silica Hybrids: Synthesis and Characterization

by Alexey V. Nelyubin, Nikolay K. Neumolotov, Vsevolod A. Skribitsky, Maria A. Teplonogova, Nikita A. Selivanov, Alexander Yu. Bykov, Victor P. Tarasov, Andrey P. Zhdanov, Konstantin Yu. Zhizhin and Nikolay T. Kuznetsov

Inorganics 2026, 14(1), 27; https://doi.org/10.3390/inorganics14010027 - 14 Jan 2026

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Abstract

Silica-based sorbents covalently modified with polyhedral boron clusters represent a promising platform for highly selective separation materials, yet robust and synthetically accessible immobilization protocols remain underdeveloped. In this work, novel sorbents based on commercially available silica gels functionalized with closo-dodecaborate anions were [...] Read more.

Silica-based sorbents covalently modified with polyhedral boron clusters represent a promising platform for highly selective separation materials, yet robust and synthetically accessible immobilization protocols remain underdeveloped. In this work, novel sorbents based on commercially available silica gels functionalized with closo-dodecaborate anions were synthesized and systematically characterized. Two immobilization strategies were compared: direct nucleophilic addition of surface aminopropyl groups to the nitrilium derivative (Bu₄N)[B₁₂H₁₁NCCH₃] and sol–gel condensation of a pre-formed boron-containing APTES-derived silane. Covalent attachment via amidine bond formation was confirmed by solution and MAS ¹¹B NMR spectroscopy, IR spectroscopy, elemental analysis/ICP-OES, and SEM. The direct grafting route afforded a boron loading of 4.5 wt% (≈20% of the theoretical capacity), with the efficiency limited by electrostatic repulsion between anionic amidine fragments on the negatively charged silica surface, whereas the APTES route gave lower absolute loading (0.085 mmol/g) due to the low specific surface area of the coarse silica support. Despite the moderate degree of functionalization, the resulting boron cluster–modified silica gels are attractive candidates for specialized chromatographic applications, where the unique hydrophobic and dihydrogen-bonding properties of closo-dodecaborates may enable selective retention of challenging analytes and motivate further optimization of surface morphology and immobilization conditions. Full article

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21 pages, 2284 KB

Open AccessArticle

Synthesis, Characterization and Anticancer Activities of Zn²⁺, Ni²⁺, Co²⁺, and Cu²⁺ Complexes of 4-Benzopyranone-2-carboxylic Acid

by Qianqian Kang, Qasim Umar, Wenjie Zhang, Xianggao Meng, Hao Yin, Mei Luo and Yanmin Zhang

Inorganics 2026, 14(1), 26; https://doi.org/10.3390/inorganics14010026 - 12 Jan 2026

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Abstract

Coordination complexes play a crucial role in modern research. 4-benzopyranone-2-carboxylic acid is a fascinating class of molecules with numerous applications, including the synthesis of pharmaceuticals and valuable chiral compounds. Antibacterial and tuberculostatic medicines, HIV protease inhibitors, intermediates in organic synthesis, and organic catalysis [...] Read more.

Coordination complexes play a crucial role in modern research. 4-benzopyranone-2-carboxylic acid is a fascinating class of molecules with numerous applications, including the synthesis of pharmaceuticals and valuable chiral compounds. Antibacterial and tuberculostatic medicines, HIV protease inhibitors, intermediates in organic synthesis, and organic catalysis are only a few of the biological applications of chiral complexes. In this study, the synthesis of four metal complexes, C₃₀H₂₈N₂NiO₁₂ [Ni(bzpyr)₂(py)₂(H₂O)₂] (I), C₃₀H₂₄CoN₂O₁₀ [Co(bzpyr)₂(py)₂(H₂O)₂] (II), C₂₀H₂₀O₁₃Zn [Zn(bzpyr)₂(H₂O)₃] (III), and C₃₀H₂₂CuN₂O₉ [Cu(bzpyr)₂(py)₂(H₂O)] (IV), is reported via direct reactions of 4-benzopyranone-2-carboxylic acid with metal salts and pyridine in anhydrous ethanol. Single-crystal X-ray diffraction analysis revealed that complexes I and II crystallize in the chiral space group P-1, whereas III and IV crystallize in the centrosymmetric space group P2₁/c. The structures of these complexes were further characterized by infrared spectroscopy, UV-Visible Diffuse Reflectance Spectroscopy, electrospray ionization mass spectrometry (ESI-MS), elemental analysis, nuclear magnetic resonance, electron paramagnetic resonance spectroscopy and single-crystal X-ray diffraction. In addition, the cytotoxic activities of complexes I–IV were evaluated against the human tumor cell lines K562, A549, HepG2, MDA-MB-231, and SW480, and molecular docking studies were conducted on the four complexes. Full article

(This article belongs to the Special Issue Metal Complexes Containing Bioactive Ligands: Structure and Biological Evaluation, 2nd Edition)

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10 pages, 3868 KB

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The Influence of Sintering Temperature on the Transport Properties of GdBa₂Cu₃O₇ Superconductor Prepared from Nano-Powders via the Co-Precipitation Method

by Ahmed Al-Mobydeen, Mohammed M. Alawamleh, Sondos Shamha, Ehab AlShamaileh, Iessa Sabbe Moosa, Jamal Rahhal, Mike Haddad, Wala`a Al-Tarawneh, Yousef Al-Dalahmeh and Imad Hamadneh

Inorganics 2026, 14(1), 25; https://doi.org/10.3390/inorganics14010025 - 7 Jan 2026

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Abstract

This study examines the influence of sintering temperature on the structural and transport properties of GdBa₂Cu₃O₇ (Gd123) superconductors prepared from nano-sized precursors via the co-precipitation method. The metal-oxalate precursor (average particle size < 50 nm) was calcined at [...] Read more.

This study examines the influence of sintering temperature on the structural and transport properties of GdBa₂Cu₃O₇ (Gd123) superconductors prepared from nano-sized precursors via the co-precipitation method. The metal-oxalate precursor (average particle size < 50 nm) was calcined at 900 °C for 12 h, and then the prepared pellets were sintered under an oxygen atmosphere in the range of 920–950 °C for 15 h. All samples showed metallic properties and a sharp superconducting transition. Critical temperatures T_C(R=0) were 94–95 K, with higher sintering temperatures steadily boosting critical current density. X-ray diffraction confirmed orthorhombic Gd123 as the dominant phase, with its phase fraction increasing from 92% to 99.8% as the sintering temperature increased. SEM micrographs showed large, densely packed grains, with higher sintering temperatures promoting improved grain connectivity and reduced porosity. The sample sintered at 950 °C exhibited the most favorable transport performance, attributed to enhanced intergranular coupling and the presence of nanoscale secondary phases acting as effective flux-pinning centers. Overall, these results demonstrate that careful control of sintering temperature can significantly optimize the microstructure and superconducting properties of Gd123 materials, supporting their advancement for practical electrical and magnetic applications. Full article

(This article belongs to the Section Inorganic Solid-State Chemistry)

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29 pages, 5015 KB

Open AccessArticle

Synthesis and Structural Characterization of Dinitrogen Chromium Complexes with Triamidoamine Ligands Possessing Bulky Substituents, and Nitrogen Fixation by These Complexes

by Takeru Kuribayashi, Yoshiaki Kokubo, Haruki Nagai, Tomoya Furui, Tomohiro Ozawa, Hideki Masuda and Yuji Kajita

Inorganics 2026, 14(1), 24; https://doi.org/10.3390/inorganics14010024 - 7 Jan 2026

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Abstract

Chromium complexes with triamidoamine derivatives bearing bulky substituents at the terminal positions of the ligands, tris(2-(3-pentylamino)ethyl)amine (H₃L^Pen) and tris(2-dicyclohexylmethylaminoethyl)amine (H₃L^Cy), are prepared: [{Cr(L^Pen)}₂(μ-N₂)] (1), [...] Read more.

Chromium complexes with triamidoamine derivatives bearing bulky substituents at the terminal positions of the ligands, tris(2-(3-pentylamino)ethyl)amine (H₃L^Pen) and tris(2-dicyclohexylmethylaminoethyl)amine (H₃L^Cy), are prepared: [{Cr(L^Pen)}₂(μ-N₂)] (1), [{CrK(L^Pen)(μ-N₂)(Et₂O)}₂] (2), [CrCl(L^Pen)] (3), [Cr(L^Cy)] (4), [CrK(L^Cy)(μ-N₂)(18-crown-6)(THF)] (5(THF)), and [CrCl(L^Cy)] (6). The preparation of these complexes is confirmed by X-ray diffraction analysis. Complexes 1, 2, and 5(THF) have coordinated dinitrogen molecules, with N–N bond lengths of 1.185(3), 1.174(9), and 1.162(3) Å, respectively. These lengths are significantly elongated compared to that of a free dinitrogen molecule (1.10 Å), indicating that the N₂ ligands are activated. The ν(¹⁴N–¹⁴N) values of 1, 2, and 5(THF) are 1715 cm⁻¹ for 1 (Raman, in solution), 1787, 1743 cm⁻¹ for 2 (IR, in solid), and 1824 cm⁻¹ for 5(THF) (IR, in solid), respectively. These values are markedly smaller than free nitrogen (2331 cm⁻¹), confirming that the dinitrogen is interacting with the metal ions and is activated. The structures of 2 and 5(THF) in solution are also studied by ¹H NMR and solution IR spectroscopies. ¹H NMR spectra of these complexes reveal that the peaks of 2 and 5(THF) are observed in the diamagnetic region, whereas those for the other complexes (1, 3, 4, and 6) exhibit paramagnetic shifts. The reactions of these complexes with K[C₁₀H₈] and HOTf under N₂ in THF yield hydrazine and a small amount of ammonia; however, they are not catalytic. The ¹H NMR and IR spectra of the products obtained by reacting 1 or 3 with reductant K in THF under N₂ atmosphere indicate that 2 is formed based on spectral agreement. Similarly, upon examining for 4 or 6, it is confirmed that a species similar to 5(THF) is generated. Full article

(This article belongs to the Special Issue State-of-the-Art Inorganic Chemistry in Japan)

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14 pages, 5202 KB

Open AccessArticle

9,10-Difluoro-9,10-disila-9,10-dihydroanthracene

by Mirei Kawamoto and Takahiro Sasamori

Inorganics 2026, 14(1), 23; https://doi.org/10.3390/inorganics14010023 - 7 Jan 2026

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Abstract

9,10-Disila-9,10-dihydroanthracenes have attracted significant attention due to their unique electronic structures, characterized by an extended π-system facilitated by σ-π conjugation. Here, we report the synthesis of 9,10-bis(p-methoxyphenyl)-9,10-disila-9,10-dihydroanthracene, which serves as a crucial precursor for the preparation of the corresponding difluoro derivative. [...] Read more.

9,10-Disila-9,10-dihydroanthracenes have attracted significant attention due to their unique electronic structures, characterized by an extended π-system facilitated by σ-π conjugation. Here, we report the synthesis of 9,10-bis(p-methoxyphenyl)-9,10-disila-9,10-dihydroanthracene, which serves as a crucial precursor for the preparation of the corresponding difluoro derivative. This conversion is achieved through a selective deanisyl-fluorination at the silicon centers using HBF₄. A key finding is the successful isolation of the cis-isomer of 9,10-difluoro-9,10-disila-9,10-dihydroanthracenes as a crystalline compound. This allowed for definitive structural characterization by single-crystal X-ray diffraction (SC-XRD) analysis, providing precise geometric insights into this electronically fascinating framework. Full article

(This article belongs to the Section Organometallic Chemistry)

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11 pages, 1740 KB

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Obtaining Titanium Dioxide from Magnesium Titanates—Products of Pyrometallurgical Processing of Oil Sandstones

by Evgenii Kuzin

Inorganics 2026, 14(1), 22; https://doi.org/10.3390/inorganics14010022 - 5 Jan 2026

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Abstract

Titanium compounds are an integral component for paint pigments, food additives (E171), catalysts, precursors for resistant structural materials, medicine, and water, and air purification and disinfection processes. A new and rather promising trend for titanium dioxide production is obtaining it from minerals with [...] Read more.

Titanium compounds are an integral component for paint pigments, food additives (E171), catalysts, precursors for resistant structural materials, medicine, and water, and air purification and disinfection processes. A new and rather promising trend for titanium dioxide production is obtaining it from minerals with magnesium titanium structure. Magnesium titanates obtained by pyrometallurgical processing of quartz–leucoxene concentrate (oil sandstones). It was found that the optimal pyrometallurgical processing conditions were 4 h and a temperature of 1425–1450 °C, with TiO₂ → Mg_XTi_YO_Z conversion exceeding 95%, and that sulfation of the magnesium titanate mixture with 60–70% H₂SO₄ for 150–210 min allows a 95% extraction of titanium compounds into solution. Investigation of the mechanism of titanium compound precipitation from Mg-Ti-containing sulfuric acid solutions revealed that in the pH range from 3 to 6, only titanium compounds were extracted from solution, while coprecipitation of magnesium compounds begins only at pH above 6.5. The product obtained by precipitation is titanium dioxide with an anatase structure, with particle distribution ranging from 0.8 to 5.0 µm and a developed surface area over 250 m²/g with mesopores characteristic of sorption materials. Full article

(This article belongs to the Special Issue Novel Ceramics and Refractory Composites)

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7 pages, 1809 KB

Open AccessCommunication

SiO₂ Electret Formation via Stamp-Assisted Capacitive Coupling: A Chemophysical Surface Functionalisation

by Edoardo Chini, Denis Gentili, Andrea Liscio and Massimiliano Cavallini

Inorganics 2026, 14(1), 21; https://doi.org/10.3390/inorganics14010021 - 4 Jan 2026

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Abstract

This work introduces a new method for creating patterned SiO₂ electrets using stamp-assisted capacitive coupling (SACC), enabling surface functionalisation without direct electrode contact. SACC applies an alternating current through capacitive coupling between a conductive stamp and an insulating substrate in high-humidity conditions, [...] Read more.

This work introduces a new method for creating patterned SiO₂ electrets using stamp-assisted capacitive coupling (SACC), enabling surface functionalisation without direct electrode contact. SACC applies an alternating current through capacitive coupling between a conductive stamp and an insulating substrate in high-humidity conditions, forming a nano-electrochemical cell that drives localised reactions. Using thermally grown SiO₂ films, we achieve submicrometre patterning with minimal topographical impact but significant electronic alterations. Characterisation via Kelvin Probe Force Microscopy and Electric Force Microscopy confirms the formation of charged regions replicating the stamp pattern, with adjustable surface potential shifts up to −1.7 V and charge densities reaching 300 nC·cm⁻². The process can be scaled to areas of 1 cm² and is compatible with conventional laboratory equipment, offering a high-throughput alternative to scanning-probe lithography. SACC combines simplicity, accuracy, and scalability, opening new opportunities for patterned electret production and functional surface engineering. Full article

(This article belongs to the Special Issue Featured Papers in Inorganic Materials 2025)

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25 pages, 4153 KB

Open AccessArticle

Reactions of Benzylsilicon Pyridine-2-olate BnSi(pyO)₃ and Selected Electrophiles—PhCHO, CuCl, and AgOTos

by Saskia Münzner, Erica Brendler and Jörg Wagler

Inorganics 2026, 14(1), 20; https://doi.org/10.3390/inorganics14010020 - 1 Jan 2026

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Abstract

In dynamic equilibria, benzylsilicon pyridine-2-olate (BnSi(pyO)₃, L) and benzaldehyde react with addition of the Si(pyO) moieties to the PhHC=O carbonyl group and formation of compounds BnSi(–O–C(H,Ph)–N^(2-pyridone))_x(pyO)_3−x (L’, L’’, and [...] Read more.

In dynamic equilibria, benzylsilicon pyridine-2-olate (BnSi(pyO)₃, L) and benzaldehyde react with addition of the Si(pyO) moieties to the PhHC=O carbonyl group and formation of compounds BnSi(–O–C(H,Ph)–N^(2-pyridone))_x(pyO)_3−x (L’, L’’, and L’’’, for x = 1, 2, 3, respectively). Addition of CuCl to a solution containing L, L’, L’’, and L’’’ results in the formation of BnSi(pyO)₃CuCl (LCuCl), shifting the equilibrium towards L with liberation of benzaldehyde. In THF as a solvent, the reaction of L in the presence of excess CuCl affords the complex LCuClCuCl. Upon dissolving in chloroform, it transforms into LCuCl with precipitation of CuCl. The solid state structure of LCuClCuCl features both the monomeric complex with CuClCuCl pattern and a dimer thereof with CuClCu(Cl)₂CuClCu pattern and a central Cu₂Cl₂ four-membered ring. This dimer of LCuClCuCl is the first crystallographically characterized representative of this Cu(I)-only Cu₄Cl₄ motif. The reaction of LCuCl and silver tosylate (AgOTos) in THF affords LCuOTos with precipitation of AgCl, whereas LAgOTos was obtained from L and AgOTos. In the crystal structure, LAgOTos features tetracoordinate Ag(I) in a distorted tetrahedral AgN₃O coordination sphere and a short Ag···Si trans-annular contact (3.3245(7) Å). ¹⁰⁹Ag NMR spectroscopy indicates a change in the coordination in solution, with δ ¹⁰⁹Ag = +551 and +419 ppm in the solid and in CDCl₃ solution, respectively. In combination, ²⁹Si NMR spectroscopy indicates changes in the Si coordination sphere, with δ ²⁹Si = −74.2 and −66.5 ppm in the solid and in CDCl₃ solution, respectively. Conversion of LAgOTos with tetraethylammonium chloride results in the precipitation of AgCl with release of L. Full article

(This article belongs to the Special Issue Synthesis, Characterization and Application of Novel Coordination and Organometallic Complexes)

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19 pages, 3156 KB

Open AccessArticle

Effect of Mn Rate on Structural, Optical and Electrical Properties in LiCo_1−xMn_xO₂ (x = 0.5; 0.7) Compounds

by Miftah Ali Bin Yazeed, Moufida Krimi, Abdulrahman Alsawi, Mohamed Houcine Dhaou, Abdelfattah Mahmoud and Abdallah Ben Rhaiem

Inorganics 2026, 14(1), 19; https://doi.org/10.3390/inorganics14010019 - 30 Dec 2025

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Abstract

The compounds LiCo_1−xMn_xO₂ (x = 0.5, 0.7) were synthesized via the solid-state method and exhibited crystallization in the cubic spinel structure (space group Fd-3m). UV–Vis spectroscopy reveals strong visible-light absorption and a reduction in the indirect optical band [...] Read more.

The compounds LiCo_1−xMn_xO₂ (x = 0.5, 0.7) were synthesized via the solid-state method and exhibited crystallization in the cubic spinel structure (space group Fd-3m). UV–Vis spectroscopy reveals strong visible-light absorption and a reduction in the indirect optical band gap from 1.85 eV (x = 0.5) to 1.60 eV (x = 0.7) with increasing Mn content, which is consistent with semiconducting behavior. This narrowing arises from Mn³⁺/Mn⁴⁺ mixed valence, which introduces mid-gap states and enhances Co/Mn 3d–O 2p orbital hybridization within the spinel framework. In contrast, the Urbach energy increases from 0.55 eV to 0.65 eV, indicating greater structural and energetic disorder in the Mn-rich composition which is attributed to the Jahn–Teller distortions and valence heterogeneity associated with Mn³⁺. Impedance and dielectric modulus analyses confirm two distinct non-Debye relaxation processes related to grains and grain boundaries. AC conductivity is governed by the Correlated Barrier Hopping (CBH) model, with bipolaron hopping identified as the dominant conduction mechanism. The x = 0.7 sample displays significantly enhanced conductivity due to increased Mn³⁺/Mn⁴⁺ mixed valence, lattice expansion, efficient 3D electronic connectivity of the spinel lattice, and reduced interfacial resistance. These findings highlight the potential of these two spinels compounds as narrow-gap semiconductors for optoelectronic applications including visible-light photodetectors, photocatalysts, and solar absorber layers extending their utility beyond conventional battery cathodes. Full article

(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials, 4th Edition)

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16 pages, 9929 KB

Open AccessArticle

Nonlinear Electrical Conductance Triggered by Partial Discharge of Fluorinated Carbon Nanotube Clusters and Its Applications in Field Grading

by Wei Zeng, Zhen Li, Yu Wang, Lei Cao, Lei Fu and Chao Wang

Inorganics 2026, 14(1), 18; https://doi.org/10.3390/inorganics14010018 - 30 Dec 2025

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Abstract

Materials with nonlinear conductivity are promising for electric field grading in various electrical and electronic devices because of their self-adaptability. In this study, we reported a nonlinear mechanism in fluorinated multi-wall carbon nanotube (F-MWCNT) clusters based on partial discharge in their porous structure. [...] Read more.

Materials with nonlinear conductivity are promising for electric field grading in various electrical and electronic devices because of their self-adaptability. In this study, we reported a nonlinear mechanism in fluorinated multi-wall carbon nanotube (F-MWCNT) clusters based on partial discharge in their porous structure. Excellent nonlinear conductivity featuring a low threshold electric field of around 2 kV/mm and a wide range of switching fields was observed after loading an ultra-low F-MWCNT loading ratio of 0.5 wt% into the UV-cured resin. Both experimental and theoretical analyses were performed to explain the underlying nonlinear mechanism. The improved electric field mitigation effect of the composite with F-MWCNT compared with the conventional inorganic fillers like SiC was validated by a flashover test in compressed SF₆ gas. Simulations were also conducted to explain the flashover threshold improvement considering the generation of seed electrons for ionization, which was in agreement with the experimental results. Full article

(This article belongs to the Special Issue Electron Emission and Related Phenomena from Inorganic Compound Surfaces)

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3 pages, 148 KB

Open AccessEditorial

Metal Complexes Diversity: Synthesis, Conformation, and Bioactivity

by Sunčica Roca and Monika Kovačević

Inorganics 2026, 14(1), 17; https://doi.org/10.3390/inorganics14010017 - 30 Dec 2025

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Abstract

Metal complexes remain central to modern inorganic chemistry due to their structural diversity [...] Full article

(This article belongs to the Special Issue Metal Complexes Diversity: Synthesis, Conformations, and Bioactivity)

10 pages, 3058 KB

Open AccessArticle

Revisiting the Solid-State Synthesis of Alkali–Tantalum(V) Oxyfluorides

by Benjamin D. E. Oreskovic, Nishani T. Manamperi and Federico A. Rabuffetti

Inorganics 2026, 14(1), 16; https://doi.org/10.3390/inorganics14010016 - 29 Dec 2025

Viewed by 563

Abstract

The solid-state synthesis of alkali–tantalum(V) oxyfluorides KTa₂O₅F and CsTa₂O₅F was revisited with the aim of streamlining their preparation as single-phase polycrystalline solids. Alkali fluorides (KF, CsF) and trifluoroacetates (KH(CF₃COO)₂, CsH(CF₃ [...] Read more.

The solid-state synthesis of alkali–tantalum(V) oxyfluorides KTa₂O₅F and CsTa₂O₅F was revisited with the aim of streamlining their preparation as single-phase polycrystalline solids. Alkali fluorides (KF, CsF) and trifluoroacetates (KH(CF₃COO)₂, CsH(CF₃COO)₂) and tantalum oxide (Ta₂O₅) were used as precursors. Reaction temperatures were optimized by means of thermal analysis coupled with powder X-ray diffraction. Phase-pure KTa₂O₅F was obtained by heating stoichiometric mixtures of KF + Ta₂O₅ and KH(CF₃COO)₂ + Ta₂O₅ at 900–1000 °C in alumina crucibles under ambient atmosphere. Similar conditions were employed to synthesize phase-pure CsTa₂O₅F from a stoichiometric mixture of CsF + Ta₂O₅ heated to 800 °C. On the other hand, the preparation of CsTa₂O₅F from a mixture of CsH(CF₃COO)₂ + Ta₂O₅ required an excess of the trifluoroacetate precursor to obtain the targeted oxyfluoride as the sole crystalline phase. Results presented herein demonstrate that mixed-metal oxyfluorides previously thought to be synthetically challenging may be synthesized via facile solid-state reactions without the need for specialized containers and stringent conditions. In addition to streamlined synthetic routes to alkali– tantalum(V) oxyfluorides, a neutron powder diffraction study of the crystal structure of KTa₂O₅F is presented to fill a gap in crystallographic databases commonly accessed by materials and solid-state chemists. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Solid-State Chemistry 2025)

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30 pages, 12826 KB

Open AccessArticle

Unveiling the Phase Formations in the Sr–Zn–Eu³⁺ Orthophosphate System: Crystallographic Analysis and Photoluminescent Properties

by Dina V. Deyneko, Ivan V. Nikiforov, Vladimir V. Titkov, Egor V. Latipov, Vadim E. Kireev, Darya A. Banaru, Sergey M. Aksenov and Bogdan I. Lazoryak

Inorganics 2026, 14(1), 15; https://doi.org/10.3390/inorganics14010015 - 28 Dec 2025

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Abstract

This study investigates phase formation in the Sr–Zn–Eu³⁺ orthophosphate system, focusing on double- and triple-phosphates. The isomorphisms and phase formation in Sr_3–1.5xEu_1+x(PO₄)₃, Sr_9–1.5xZn_1.5Eu_x(PO₄) [...] Read more.

This study investigates phase formation in the Sr–Zn–Eu³⁺ orthophosphate system, focusing on double- and triple-phosphates. The isomorphisms and phase formation in Sr_3–1.5xEu_1+x(PO₄)₃, Sr_9–1.5xZn_1.5Eu_x(PO₄)₇, Sr_9.5–1.5xZnEu_x(PO₄)₇, Sr_3–xZn_xEu(PO₄)₃, and Sr_3–xZn_x(PO₄)₂ series were studied using powder X-ray diffraction and Rietveld refinement. A ternary phase diagram was constructed, identifying concentration limits for pure phases and multi-phase regions as well as areas of stabilization of strontiowhitlockite-, palmierite-, eulytite-, and strontiohurlbutite-type phases. The combinatorial complexity of Sr-based phosphates is discussed. The β-Sr₃(PO₄)₂ isostructural to whitlockite was found to exhibit the highest isomorphic capacity for Eu³⁺ cations, which is advantageous for its application as a red-emitting phosphor. Photoluminescence properties were studied, and analyzed based on structural data. Photoluminescence studies confirmed intense red-emission dominated by the ⁵D₀ → ⁷F₂ transition of Eu³⁺, with the β-Sr₃(PO₄)₂-based phosphor showing the highest emission intensity. Full article

(This article belongs to the Special Issue Photoluminescence and Scintillation Properties of Rare Earth-Doped Materials)

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11 pages, 1863 KB

Open AccessArticle

Design and Structural Characterization of Ferrocenyl Bithiophene Thioketone-Based Iron Complexes

by Ibrahim Basma, Hassan Abul-Futouh, Alessia Cinci, Sara J. Abaalkhail, Abdulmajeed Abdullah Alayyaf, Phil Köhler and Wolfgang Weigand

Inorganics 2026, 14(1), 14; https://doi.org/10.3390/inorganics14010014 - 28 Dec 2025

Viewed by 333

Abstract

The exceptional catalytic efficiency of [FeFe]-hydrogenases has driven intense efforts to reproduce their structure and function in synthetic models. A key structural feature governing the behavior of synthetic H-cluster analogs lies in the identity of the bridging dithiolato ligands that link the iron [...] Read more.

The exceptional catalytic efficiency of [FeFe]-hydrogenases has driven intense efforts to reproduce their structure and function in synthetic models. A key structural feature governing the behavior of synthetic H-cluster analogs lies in the identity of the bridging dithiolato ligands that link the iron centers. These ligands play a pivotal role in tuning the electron density of the metal core, thereby dictating the complex’s redox characteristics and catalytic reactivity. In this context, we herein describe the synthesis and application of ferrocenyl bithiophene-2,2′-yl thioketone (1) as a proligand for assembling biomimetic models of the [FeFe]-hydrogenase active site. The obtained complexes were thoroughly examined using a suite of analytical methods, including NMR and IR spectroscopy, elemental analysis, and a single-crystal X-ray diffraction, affording comprehensive structural and chemical characterization. Furthermore, their electrochemical behavior toward proton reduction and hydrogen evolution was evaluated via cyclic voltammetry, enabling direct comparison with structurally related analogs. Full article

(This article belongs to the Special Issue Iron Complexes as Models of [FeFe] Hydrogenases)

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19 pages, 2050 KB

Open AccessArticle

Egg White Assisted Synthesis of Fe-Mn Spinel Oxides: Effects of Egg White Ratio, Oxygen Partial Pressure, and Life Cycle Impacts

by Ann-Katrin Emmerich, Vanessa Zeller, Xingmin Liu, Anke Weidenkaff and Marc Widenmeyer

Inorganics 2026, 14(1), 13; https://doi.org/10.3390/inorganics14010013 - 27 Dec 2025

Cited by 1 | Viewed by 335

Abstract

Egg white was chosen as a renewable, non-toxic agent for the synthesis of FeMn₂O₄ spinel pre-catalysts to avoid the use of critical transition metals such as Ni and Co. However, synthesizing phase-pure FeMn₂O₄ remains challenging due to [...] Read more.

Egg white was chosen as a renewable, non-toxic agent for the synthesis of FeMn₂O₄ spinel pre-catalysts to avoid the use of critical transition metals such as Ni and Co. However, synthesizing phase-pure FeMn₂O₄ remains challenging due to (i) the requirement of low oxygen partial pressures to counter rapid reoxidation of Mn₃O₄ in the presence of iron oxides, which can be achieved by the preferred oxidation of the egg white during the calcination, and (ii) the probable formation of Fe₃O₄ and Mn₃O₄ during intermediate steps in the reaction, leading to multiphase spinel formation caused by a miscibility gap between the spinels. In contrast, spinels with Ni, Co, Zn, or Al are phase-pure. Egg white has significant environmental impacts in the synthesis of all spinel manganites, as assessed from a life-cycle perspective, which can exceed those of petroleum-based agents such as ethylenediaminetetraacetic acid (EDTA) in most impact categories. Therefore, our results show that the investigated synthesis route is not more sustainable, and we demonstrate that implementing quantitative evaluation of environmental impacts already at an early stage is essential to determine whether a synthesis is truly sustainable. Full article

(This article belongs to the Section Inorganic Materials)

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15 pages, 3205 KB

Open AccessArticle

Extending Hexagon-Based Metal–Organic Frameworks—Mn(II) and Gd(III) MOFs with Hexakis(4-(4-Carboxyphenyl)phenyl)benzene

by Henrik Björck, William Reinholdsson, Ocean Cheung, Guojon Zhou, Zhehao Huang, Francoise M. Amombo Noa and Lars Öhrström

Inorganics 2026, 14(1), 12; https://doi.org/10.3390/inorganics14010012 - 27 Dec 2025

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Abstract

Hexakis(4-(4-carboxylphenyl)phenyl)benzene, H₆cbb, was used to prepare the rod-based metal–organic frameworks (rod-MOFs) [Mn₄(cbb)(dmf)₂(OAc)₂] CTH-50 and [Gd₃(cbb)(dmf)₂(H₂O)(OAc)₃] CTH-51 by solvothermal synthesis (dmf = N,N-dimethylformamide) with single crystal diffraction revealing [...] Read more.

Hexakis(4-(4-carboxylphenyl)phenyl)benzene, H₆cbb, was used to prepare the rod-based metal–organic frameworks (rod-MOFs) [Mn₄(cbb)(dmf)₂(OAc)₂] CTH-50 and [Gd₃(cbb)(dmf)₂(H₂O)(OAc)₃] CTH-51 by solvothermal synthesis (dmf = N,N-dimethylformamide) with single crystal diffraction revealing that CTH-50 (by X-ray) and CTH-51 (by electron diffraction) can be described as 5- and 6-connected yav-nets. Gas sorption analysis gave a BET surface area of 787 m²/g for CTH-50 and 187 m²/g for CTH-51, with CTH-50 having an Ideal Adsorbed Solution Theory (IAST) selectivity for SF₆ of 35 at 10 kPa, and thermogravimetry indicated the possible stability of CTH-50 to 300 °C and CTH-51 to 400 °C. Full article

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23 pages, 3557 KB

Open AccessArticle

Formation and Reversible Cleavage of an Unusual Trisulfide-Bridged Binuclear Pyridine Diimine Iridium Complex

by Max Völker, Thomas Marx and Peter Burger

Inorganics 2026, 14(1), 11; https://doi.org/10.3390/inorganics14010011 - 26 Dec 2025

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Abstract

Iridium pyridine diimine (PDI) complexes provide a versatile platform for highly reactive Ir–nitrido species with pronounced multiple-bond character, capable of activating H–H, C–H, Si–H, and even C–C bonds. Building on this chemistry, we extended our studies to a system with a terminal Ir–S [...] Read more.

Iridium pyridine diimine (PDI) complexes provide a versatile platform for highly reactive Ir–nitrido species with pronounced multiple-bond character, capable of activating H–H, C–H, Si–H, and even C–C bonds. Building on this chemistry, we extended our studies to a system with a terminal Ir–S bond, starting from our recently reported PDI–Ir–SH complex, which exhibits partial multiple-bond character. Upon addition of the 2,4,6-tri-tert-butylphenoxy radical, the corresponding phenol and a tentative Ir–S• radical intermediate are formed at ambient temperature. DFT and LNO-CCSD(T) calculations consistently reveal a low barrier for this process, with the spin density localized primarily on sulfur, accounting for subsequent S–S coupling reactions. Instead of the anticipated dimeric disulfido Ir–S₂–Ir complex formed along a least-motion pathway, a trisulfido Ir–S₃–Ir species was obtained, and characterized by NMR spectroscopy, X-ray crystallography and mass spectrometry. The formation mechanism of the trisulfido complex was further elucidated by DFT calculations. Remarkably, the sulfur-bridge formation is thermally reversible, regenerating the monomeric sulfanido Ir–SH complex. The origin of the hydrogen atom was investigated using H₂, D₂, and deuterated solvents. Full article

(This article belongs to the Section Coordination Chemistry)

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42 pages, 1822 KB

Open AccessReview

Reversibility as a Design Principle in Inorganic, Organometallic and Organic Redox Mediators for Biosensors

by Angel A. J. Torriero

Inorganics 2026, 14(1), 10; https://doi.org/10.3390/inorganics14010010 - 26 Dec 2025

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Abstract

Redox mediators are central to electrochemical biosensors, enabling electron transfer between deeply buried enzymatic cofactors and electrode surfaces when direct electron transfer is kinetically inaccessible. Among all design parameters, the reversibility of mediator redox cycling remains the most decisive yet under-examined factor governing [...] Read more.

Redox mediators are central to electrochemical biosensors, enabling electron transfer between deeply buried enzymatic cofactors and electrode surfaces when direct electron transfer is kinetically inaccessible. Among all design parameters, the reversibility of mediator redox cycling remains the most decisive yet under-examined factor governing biosensor stability, drift and long-term reproducibility. This review establishes reversibility as a unifying framework grounded in inorganic and organometallic redox chemistry, with particular emphasis on coordination environments, ligand-field effects and outer-sphere electron-transfer pathways. Recent advances (2010–2025) in ruthenium and osmium polypyridyl complexes, cobalt macrocycles, hexacyanoferrates and Prussian Blue analogues are examined alongside ferrocene derivatives and other organometallic mediators, which together define the upper limits of reversible behaviour. Organic mediator families, including quinones, phenazines, indophenols, aminophenols and viologens, are discussed as mechanistic contrasts that highlight the structural and thermodynamic constraints that limit long-term cycling in aqueous media. Mechanistic indicators of reversibility, including peak separation, current ratios and heterogeneous electron-transfer rate constants, are linked to mediator architecture, coordination chemistry and immobilisation environment. By integrating molecular electrochemistry with applied sensor engineering, this review provides a mechanistically grounded basis for selecting or designing redox mediators that sustain efficient electron transfer, minimal fouling and calibration stability across diverse sensing platforms. Full article

(This article belongs to the Section Bioinorganic Chemistry)

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10 pages, 1704 KB

Open AccessArticle

Phase Relations and Solid Solutions in the YbBO₃–ScBO₃ System

by Yerassyl Zholdas, Artem Kuznetsov, Asset Bolatov, Ammar Jamous, Valery Svetlichnyi and Konstantin Kokh

Inorganics 2026, 14(1), 9; https://doi.org/10.3390/inorganics14010009 - 25 Dec 2025

Viewed by 409

Abstract

The YbBO₃–ScBO₃ system was studied across the selected compositional range by means of solid-state synthesis, powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and photoluminescence spectroscopy. XRD of annealed samples at 1300–1400 °C revealed that the system reaches equilibrium and [...] Read more.

The YbBO₃–ScBO₃ system was studied across the selected compositional range by means of solid-state synthesis, powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and photoluminescence spectroscopy. XRD of annealed samples at 1300–1400 °C revealed that the system reaches equilibrium and consists of two phases, YbBO₃ and ScBO₃, separated by a two-phase region. The lattice parameters show a limited solubility between Yb³⁺ and Sc³⁺ ions. DSC measurements display a broad endothermic feature at approximately 1480 °C, corresponding to the eutectic point. Near-infrared emission excited at 975–980 nm originates from Yb³⁺ ions and shows the highest intensity for pure YbBO₃ and for the Sc-rich composition, while intermediate samples exhibit weaker luminescence. Full article

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

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1 pages, 378 KB

Open AccessCorrection

Correction: Kaptanoglu, M. Green Manufacturing of Rutile (TiO₂) Welding Electrodes with Blast Furnace Slag. Inorganics 2025, 13, 361

by Mustafa Kaptanoglu

Inorganics 2026, 14(1), 8; https://doi.org/10.3390/inorganics14010008 - 25 Dec 2025

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Abstract

In the original publication [...] Full article

(This article belongs to the Section Inorganic Materials)

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14 pages, 2997 KB

Open AccessArticle

Cobalt Single-Atom Anchored Tubular Graphyne for Electrocatalytic CO₂ Reduction Reaction

by Shannan Xu, Xiao Tang, Chen Long, Dongqiu Zhao and Lin Ju

Inorganics 2026, 14(1), 7; https://doi.org/10.3390/inorganics14010007 - 24 Dec 2025

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Abstract

Electrochemical CO₂ reduction reaction through utilizing renewable electricity under mild conditions is a promising pathway toward achieving carbon neutrality. In this work, we designed a tubular graphyne functionalized with isolated Co single atom and lowered the activation energy barrier of its rate-determining [...] Read more.

Electrochemical CO₂ reduction reaction through utilizing renewable electricity under mild conditions is a promising pathway toward achieving carbon neutrality. In this work, we designed a tubular graphyne functionalized with isolated Co single atom and lowered the activation energy barrier of its rate-determining step to as low as 0.46 eV. The catalytic performance was systematically evaluated through density functional theory calculations. Compared with the planar graphyne functionalized with isolated Co single atom, the tubular one not only significantly improves the utilization efficiency of Co single atoms by exposing them more thoroughly, but also increases the catalytic activity of Co single atom by enhancing electron density of states at the Fermi level, which causes a higher level of activation state for the adsorbed CO₂ molecules. Furthermore, it brought about the CO₂-to-CH₄ reduction reaction pathway, resulting in remarkable catalytic activity and high methane selectivity. Our study demonstrates the efficacy of curvature engineering in enhancing the intrinsic activity of single-atom catalysts, offering a novel strategy for designing advanced carbon cycle catalysts. Full article

(This article belongs to the Special Issue Single-Atom Catalysis: Advances in Synthesis, Characterization, and Applications)

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24 pages, 7749 KB

Open AccessArticle

Synthesis of Aluminum-Based MOF and Cellulose-Modified Al-MOF for Enhanced Adsorption of Congo Red Dye

by Ceyda Duyar and Asgar Kayan

Inorganics 2026, 14(1), 6; https://doi.org/10.3390/inorganics14010006 - 23 Dec 2025

Viewed by 576

Abstract

The synthesis of two novel materials, aluminum-based MOF (Al-MOF) and cellulose-modified MOF (Al-MOF@C), as adsorbents is presented. Al-MOF was synthesized from aluminum sec-butoxide and terephthalic acid in a 1:1 molar ratio using a solvothermal method. Al-MOF@C was synthesized under similar solvothermal conditions [...] Read more.

The synthesis of two novel materials, aluminum-based MOF (Al-MOF) and cellulose-modified MOF (Al-MOF@C), as adsorbents is presented. Al-MOF was synthesized from aluminum sec-butoxide and terephthalic acid in a 1:1 molar ratio using a solvothermal method. Al-MOF@C was synthesized under similar solvothermal conditions by reacting environmentally friendly starting materials such as aluminum sec-butoxide, terephthalic acid, and cellulose in a 1:1:1 molar ratio. The synthesized materials’ structural, morphological, and surface properties were thoroughly characterized using XRD, SEM, EDS, BET (with specific surface areas calculated as 563.9 m²/g for Al-MOF and 487.1 m²/g for Al-MOF@C), and FTIR analyses. Then they were utilized in the water treatment process to remove the highly toxic anionic Congo red (CR) dye. Dye adsorption studies were carried out using UV-Vis spectroscopy. Batch adsorption experiments showed that Al-MOF and Al-MOF@C materials adsorbed CR dye with removal efficiencies of 95.06% and 91.79% in just 4 min, respectively. The equilibrium adsorption isotherm data for Al-MOF and Al-MOF@C were best fitted by the Langmuir model, and the calculated maximum adsorption capacities were 80.64 mg/g and 68.96 mg/g, respectively. The adsorption kinetics exhibited an excellent correlation with the pseudo-second-order model (R² = 0.9975 for Al-MOF and R² = 0.9936 for Al-MOF@C). Measurements taken after the adsorption process showed that Al-MOFs synthesized using environmentally friendly chemicals retained their stable chemical structure in aqueous environments and thus did not create secondary pollution in the environment, highlighting the importance of this study. Chemically stable, thermodynamically favorable, and highly reusable Al-MOF adsorbents offer a promising solution for the advanced environmental remediation of hazardous dye contaminants. Full article

(This article belongs to the Special Issue Advances in Inorganic–Organic Composite Photocatalysts for Energy and Environmental Applications)

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15 pages, 2284 KB

Open AccessArticle

Preparation of Fe₃O₄/P(U-AM-ChCl) Composite Hydrogel and Study on Its Mechanical and Adsorption Properties

by Yuzuo Liu, Jiawei Li, Bin Li, Zhigang Hu, Mengjing Zhou, Haoyu Lv and Ying Wang

Inorganics 2026, 14(1), 5; https://doi.org/10.3390/inorganics14010005 - 23 Dec 2025

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Abstract

This study employed urea (U), acrylamide (AM), and choline chloride (ChCl) as raw materials to synthesize a deep eutectic solvent (DES), incorporated dispersed Fe₃O₄ as a filler within the DES, and effectively fabricated Fe₃O₄/P(U-AM-ChCl) composite hydrogels [...] Read more.

This study employed urea (U), acrylamide (AM), and choline chloride (ChCl) as raw materials to synthesize a deep eutectic solvent (DES), incorporated dispersed Fe₃O₄ as a filler within the DES, and effectively fabricated Fe₃O₄/P(U-AM-ChCl) composite hydrogels through in situ polymerization (SP). The hydrogels were analyzed through Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The influence of different Fe₃O₄ contents on the swelling behavior, anti-fatigue properties, and adsorption efficiency of the composite hydrogels was thoroughly examined. The results indicated that, in comparison to the hydrogel lacking Fe₃O₄, the hydrogel containing 1 wt% Fe₃O₄ demonstrated enhanced swelling and anti-fatigue characteristics, with its equilibrium swelling ratio (ESR) increasing by 16.34%, the time to achieve swelling equilibrium decreasing by 60%, the maximum stress recovery rate rising by 7.8%, and the toughness recovery rate improving by 7.28%.The adsorption efficiency of the hydrogel was improved, and adsorption equilibrium was achieved more quickly, due to the supplementary adsorption sites introduced by Fe₃O₄. When the Fe₃O₄/P(U-AM-ChCl) composite hydrogel was immersed in a 120 mg/L Cu²⁺ so-lution for 48 h, the adsorption capacity reached 171.5 mg/g. This study introduces a novel, viable approach for synthesizing hydrogels with reduced pore sizes and enhanced functionality, while also illustrating their prospective utility in water purification applications. Full article

(This article belongs to the Section Inorganic Materials)

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16 pages, 3357 KB

Open AccessArticle

Synergistic Optimization of Multiple Properties: Enhancement Mechanism of Thermoelectric and Mechanical Performances of Ta-Doped In₂O₃ Materials for Advanced Energy Harvesting Applications

by Jiang Zhu, Jie Zhang, Bo Feng, Yaoyang Zhang, Xiaoqiong Zuo, Zhiwen Yang, Tongqiang Xiong, Wenzheng Li, Tong Tang, Suoluoyan Yang and Ruolin Ruan

Inorganics 2026, 14(1), 4; https://doi.org/10.3390/inorganics14010004 - 22 Dec 2025

Viewed by 345

Abstract

To improve the comprehensive performance of indium oxide (In₂O₃) thermoelectric materials, this study systematically investigates the regulatory effects of tantalum (Ta) doping on their electrical transport characteristics, thermoelectric conversion efficiency, and mechanical properties. The results show that Ta doping [...] Read more.

To improve the comprehensive performance of indium oxide (In₂O₃) thermoelectric materials, this study systematically investigates the regulatory effects of tantalum (Ta) doping on their electrical transport characteristics, thermoelectric conversion efficiency, and mechanical properties. The results show that Ta doping achieves synchronous optimization of multiple properties through precise regulation of crystal structure, electronic structure, and microdefects. In terms of electrical transport, the electron doping effect of Ta⁵⁺ substituting In³⁺ and the introduction of impurity levels lead to a continuous increase in carrier concentration; lattice relaxation and impurity band formation at high doping concentrations promote mobility to first decrease and then increase, resulting in a significant growth in electrical conductivity. Although the absolute value of the Seebeck coefficient slightly decreases, the growth rate of electrical conductivity far exceeds the attenuation rate of its square, increasing the power factor from 1.83 to 5.26 μWcm⁻¹K⁻² (973 K). The enhancement of density of states near the Fermi level not only optimizes carrier transport efficiency but also provides electronic structure support for synergistic performance improvement. For thermoelectric conversion efficiency, the substantial increase in power factor collaborates with thermal conductivity suppression induced by lattice distortion and impurity scattering, leading to a leapfrog increase in ZT value from 0.055 to 0.329 (973 K). In terms of mechanical properties, lattice distortion strengthening, formation of strong Ta-O covalent bonds, and dispersion strengthening effect significantly improve the Vickers hardness of the material. Ta doping breaks the bottleneck of mutual property constraints in traditional modification through an integrated mechanism of “electronic structure regulation-carrier transport optimization-multiple performance synergistic enhancement”, providing a key strategy for designing high-performance indium oxide-based thermoelectric materials and facilitating their practical application in the field of green energy conversion. Full article

(This article belongs to the Section Inorganic Materials)

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27 pages, 5433 KB

Open AccessArticle

Comprehensive Structural, Electronic, and Biological Characterization of fac-[Re(CO)₃(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)Br]: X-Ray, Aromaticity, Electrochemistry, and HeLa Cell Viability

by Alexander Carreño, Vania Artigas, Evys Ancede-Gallardo, Rosaly Morales-Guevara, Roxana Arce, Luis Leyva-Parra, Angel A. Martí, Camila Videla, María Carolina Otero and Manuel Gacitúa

Inorganics 2026, 14(1), 3; https://doi.org/10.3390/inorganics14010003 - 22 Dec 2025

Viewed by 745

Abstract

The rhenium(I) tricarbonyl complex fac-[Re(CO)₃(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)Br] (ReL) has previously demonstrated promising luminescent properties, enabling its direct application as a probe for walled cells such as Candida albicans and Salmonella enterica. In this new study, we present a significantly expanded and [...] Read more.

The rhenium(I) tricarbonyl complex fac-[Re(CO)₃(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)Br] (ReL) has previously demonstrated promising luminescent properties, enabling its direct application as a probe for walled cells such as Candida albicans and Salmonella enterica. In this new study, we present a significantly expanded and comprehensive characterization of ReL, incorporating a wide range of experimental and computational techniques not previously reported. These include variable-temperature ¹H and ¹³C NMR spectroscopy, CH-COSY, single-crystal X-ray diffraction, Hirshfeld surface analysis, DFT calculations, Fukui functions, non-covalent interaction (NCI) indices, and electrochemical profiling. Structural analysis confirmed a pseudo-octahedral geometry with the bromide ligand positioned cis to the epoxy group. NMR data revealed the coexistence of cis and trans isomers in solution, with the trans form being slightly more stable. DFT calculations and aromaticity descriptors indicated minimal electronic differences between isomers, supporting their unified treatment in subsequent analyses. Electrochemical studies revealed two oxidation and two reduction events, consistent with ECE and EEC mechanisms, including a Re(I) → Re(0) transition at −1.50 V vs. SCE. Theoretical redox potentials showed strong agreement with experimental data. Biological assays revealed a dose-dependent cytotoxic effect on HeLa cells, contrasting with previously reported low toxicity in microbial systems. These findings, combined with ReL’s luminescent and antimicrobial properties, underscore its multifunctional nature and highlight its potential as a bioactive and imaging agent for advanced therapeutic and microbiological applications. Full article

(This article belongs to the Special Issue Biological Activity of Metal Complexes)

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21 pages, 4466 KB

Open AccessArticle

Biogenic Fabrication of Ag-NPs@Hydroxyapatite from Goat Bone Waste: A Sustainable Route for Photocatalytic and Antioxidant Applications

by Ahmed Hamad Alanazi, Ali Atta, Hallouma Bilel, Riyadh F. Halawani, Fahed A. Aloufi, Amnah Salem Al Zbedy and Amr Mohammad Nassar

Inorganics 2026, 14(1), 2; https://doi.org/10.3390/inorganics14010002 - 22 Dec 2025

Cited by 1 | Viewed by 901

Abstract

In this study, we present a new, facile, and eco-friendly approach to the synthesis of silver nanoparticles using an aqueous extract obtained from wasted goat bone, which acted as a reducing and stabilizing agent. Hydroxyapatite (GHAP) derived from the same biogenic source was [...] Read more.

In this study, we present a new, facile, and eco-friendly approach to the synthesis of silver nanoparticles using an aqueous extract obtained from wasted goat bone, which acted as a reducing and stabilizing agent. Hydroxyapatite (GHAP) derived from the same biogenic source was then added to the Ag-NPs solution, resulting in the formation of a nanocomposite (Ag@GHAP). Biogenic GHAP and Ag@GHAP have been characterized using Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), atomic force microscopy (AFM), and powder X-ray diffraction (XRD), confirming the formation of crystalline GHAP with well-dispersed silver nanoparticles. According to AFM studies, the Ag@GHAP composite exhibits a higher surface roughness alteration than GHAP. XRD revealed that the crystalline sizes of GHAP and Ag@GHAP are 10.2 and 15.6 nm, respectively. Zeta potential showed that GHAP and Ag@GHAP possessed values of −12.4 and −11.7 mV, respectively. Ag@GHAP showed a promising performance in photocatalysis and antioxidant applications as compared to GHAP. The energy band gap (Eg) values are 5.1 eV and 4.5 eV for GHAP and Ag@GHAP, respectively. Ag@GHAP showed photocatalytic activity during the degradation of methylene blue dye (5 ppm) under solar irradiation with a removal efficiency of 99.15% in 100 min at the optimum conditions. The antioxidant activity of GHAP and Ag@GHAP was determined using the DPPH method. The results showed enhanced antioxidant activity of a silver decorated sample with IC50 values of 36.83 and 2.95 mg/mL, respectively. As a result, the Ag@GHAP composite is a promising candidate in environmental treatment and scavenging of free radicals. Full article

(This article belongs to the Special Issue Nanocomposites for Photocatalysis, 2nd Edition)

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Inorganics, Volume 14, Issue 1 (January 2026) – 31 articles

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