Pub Date : 2026-02-01Epub Date: 2025-11-19DOI: 10.1016/j.poly.2025.117901
Shuchang Luo , Jun Zhao , Lingdong Liu , Hao Yang , Xiaoyuan Sun
This study investigates the influence of axial ligand substituents (1-AdO (1), –OtBu (2), –OCH3 (3), –OC2H5 (4), –OC3H7 (5), –OiPr (6), –OC6H5 (7), –O–C(CF3)3 (8), –S–C(CH3)3 (9), –Se–C(CH3)3 (10), and –N(CH3)2 (11)), Dy–Oaxi bond lengths, and Oaxi–Dy–Oaxi bond angles on the magnetic properties of alkoxy-coordinated [Dy(18-C-6)L2]+ complexes through ab initio calculations on air-stable crown dysprosium(III)-based single-molecule magnets (Dy-SMMs). The magnetic performance of this series of SMMs can be preliminarily evaluated based on the quantum tunnelling of magnetization time (τQTM) and effective energy barrier (Ueff). Among these complexes, the OtBu-substituted derivative, featuring a linear Oaxi–Dy–Oaxi bond angle of 180° and an optimal Dy–Oaxi bond length of 1.95 Å, exhibits the highest blocking temperature, longest τQTM, and highest Ueff. These findings provide crucial theoretical insights for understanding the magnetic nature of Dy-SMMs and guiding the design of high-performance SMMs.
{"title":"The effect of axial ligands on the magnetic properties of oxygen-coordinated Dy-SMMs: Theoretical insights","authors":"Shuchang Luo , Jun Zhao , Lingdong Liu , Hao Yang , Xiaoyuan Sun","doi":"10.1016/j.poly.2025.117901","DOIUrl":"10.1016/j.poly.2025.117901","url":null,"abstract":"<div><div>This study investigates the influence of axial ligand substituents (1-AdO (<strong>1</strong>), –O<sup>t</sup>Bu (<strong>2</strong>), –OCH<sub>3</sub> (<strong>3</strong>), –OC<sub>2</sub>H<sub>5</sub> (<strong>4</strong>), –OC<sub>3</sub>H<sub>7</sub> (<strong>5</strong>), –O<sup>i</sup>Pr (<strong>6</strong>), –OC<sub>6</sub>H<sub>5</sub> (<strong>7</strong>), –O–C(CF<sub>3</sub>)<sub>3</sub> (<strong>8</strong>), –S–C(CH<sub>3</sub>)<sub>3</sub> (<strong>9</strong>), –Se–C(CH<sub>3</sub>)<sub>3</sub> (<strong>10</strong>), and –N(CH<sub>3</sub>)<sub>2</sub> (<strong>11</strong>)), Dy–O<sub>axi</sub> bond lengths, and O<sub>axi</sub>–Dy–O<sub>axi</sub> bond angles on the magnetic properties of alkoxy-coordinated [Dy(18-C-6)L<sub>2</sub>]<sup>+</sup> complexes through ab initio calculations on air-stable crown dysprosium(III)-based single-molecule magnets (Dy-SMMs). The magnetic performance of this series of SMMs can be preliminarily evaluated based on the quantum tunnelling of magnetization time (<em>τ</em><sub>QTM</sub>) and effective energy barrier (<em>U</em><sub>eff</sub>). Among these complexes, the O<sup>t</sup>Bu-substituted derivative, featuring a linear O<sub>axi</sub>–Dy–O<sub>axi</sub> bond angle of 180° and an optimal Dy–O<sub>axi</sub> bond length of 1.95 Å, exhibits the highest blocking temperature, longest <em>τ</em><sub>QTM</sub>, and highest <em>U</em><sub>eff</sub>. These findings provide crucial theoretical insights for understanding the magnetic nature of Dy-SMMs and guiding the design of high-performance SMMs.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"284 ","pages":"Article 117901"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-22DOI: 10.1016/j.poly.2025.117902
Krishna Chandra Murmu , Debashis Saha , Juli Nanda Goswami , Urmila Saha , Bhriguram Das , Surajit Biswas , Ennio Zangrando , Malay Dolai
The capture and conversion of carbon dioxide from sustainable source has proven as a viable alternative in the production of key organic compounds. Here, the in-situ synthesis of a zinc metal complex, [Zn(II)2(H2L)(HL)](ClO4)3 (1), using 2-acetyl pyridine and succinic-hydrazide is addressed. The single crystal X-ray diffraction data of 1 revealed a dinuclear species with the two octahedral symmetry related zinc metal ions co-ordinated by a N4O2 donor set. Complex 1 acts as an efficient catalyst in the preparation of N-methylated products from amines through CO2 fixation reaction. The involvement of cost effective polymethylhydrosiloxane (PMHS), a reducing agent obtained as a by-product from numerous reactions, makes this protocol more sustainable and environmentally friendly. A variety of N-methylated derivatives was produced from the correspondent aromatic amines with high yield and selectivity at 90 °C temperature under carbon dioxide at 1 atm pressure after 6–10 h of reaction. Even heterocyclic non aromatic amines furnished a very good percentage (96–98 %) of the desired N-methyl products via the same catalytic reaction in just 5 h of reaction time. The catalyst effectiveness of this catalysis process can be easily recognized by the high TON (2.2 × 104–3.2 × 104) and TOF values (2.2 × 103–6.4 × 103 h−1) observed.
{"title":"Binuclear zinc(II) complex as an efficient catalyst for selective N-methylation reaction of amines with CO2 under mild reaction conditions","authors":"Krishna Chandra Murmu , Debashis Saha , Juli Nanda Goswami , Urmila Saha , Bhriguram Das , Surajit Biswas , Ennio Zangrando , Malay Dolai","doi":"10.1016/j.poly.2025.117902","DOIUrl":"10.1016/j.poly.2025.117902","url":null,"abstract":"<div><div>The capture and conversion of carbon dioxide from sustainable source has proven as a viable alternative in the production of key organic compounds. Here, the in-situ synthesis of a zinc metal complex, [Zn(II)<sub>2</sub>(H<sub>2</sub>L)(HL)](ClO<sub>4</sub>)<sub>3</sub> (<strong>1</strong>), using 2-acetyl pyridine and succinic-hydrazide is addressed. The single crystal X-ray diffraction data of <strong>1</strong> revealed a dinuclear species with the two octahedral symmetry related zinc metal ions co-ordinated by a N<sub>4</sub>O<sub>2</sub> donor set. Complex <strong>1</strong> acts as an efficient catalyst in the preparation of <em>N</em>-methylated products from amines through CO<sub>2</sub> fixation reaction. The involvement of cost effective polymethylhydrosiloxane (PMHS), a reducing agent obtained as a by-product from numerous reactions, makes this protocol more sustainable and environmentally friendly. A variety of <em>N</em>-methylated derivatives was produced from the correspondent aromatic amines with high yield and selectivity at 90 °C temperature under carbon dioxide at 1 atm pressure after 6–10 h of reaction. Even heterocyclic non aromatic amines furnished a very good percentage (96–98 %) of the desired <em>N</em>-methyl products via the same catalytic reaction in just 5 h of reaction time. The catalyst effectiveness of this catalysis process can be easily recognized by the high TON (2.2 × 10<sup>4</sup>–3.2 × 10<sup>4</sup>) and TOF values (2.2 × 10<sup>3</sup>–6.4 × 10<sup>3</sup> h<sup>−1</sup>) observed.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"284 ","pages":"Article 117902"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-28DOI: 10.1016/j.poly.2025.117909
Abdelatif Messaoudi
This study presents a comprehensive theoretical analysis of a series of bimetallic diruthenium complexes [Cp‡Ru(μ-H)3IrCp⁎], [Cp‡Ru(μ-H)3RhCp⁎], [Cp‡Ru (μ-H)3{Ru(p-cymene)}], [Cp‡Ru(μ-H)3{Ru(benzene)}] and [Cp‡Ru(μ-H)2(μ-Cl){Ru(p-cymene)}] (Cp* = C5Me5, Cp‡ = C5tBu3H2, p-cymene = CH3C6H4CH(CH3)2)) (A1-A5), incorporating various metal centers (Ir, Rh) and ligands (hydrides, chloride, Cp*) using density functional theory (DFT) at the B3LYP level with LanL2DZ and def2-TZVP basis sets. The geometric structures, electronic configurations, molecular orbitals, global reactivity descriptors, electrostatic potentials, atomic charges, TDOS, UV–Vis absorption spectra, and nonlinear optical (NLO) properties were systematically investigated. Geometry optimizations reveal excellent agreement with experimental data, with def2-TZVP offering slightly improved accuracy in metal-ligand bond distances and angles. The HOMO-LUMO gap analysis and frontier molecular orbitals show that complexes A1 and A5 have the narrowest gaps, indicating higher reactivity, while A3 displays the highest electron delocalization and charge transfer capability. Reactivity descriptors position A2 as the most electrophilic species, with high electronegativity and electron affinity, whereas A3 acts as the best donor. Molecular electrostatic potential (MESP) maps show distinct charge distributions and identify nucleophilic and electrophilic regions, highlighting the strong influence of ligand identity. Charge analysis supports significant polarization effects, particularly in A5 due to the chloride ligand. UV–Vis spectral simulations predict strong absorption in the visible region for A5, with metal to ligand charge transfer (MLCT) and π → π* transitions, indicating potential in photonic applications. Furthermore, NLO property analysis reveals that A3-A5 exhibit substantial hyperpolarizabilities, suggesting their promise as materials for second-order NLO applications. Altogether, this work underscores the sensitivity of electronic and optical properties to ligand environment, metal type, and computational treatment, offering valuable guidance for the design of functional organometallic complexes in catalysis, optoelectronics, and molecular electronics.
{"title":"Electronic structure and reactivity of mixed-ligand dinuclear RuIr, RuRh, and RuRu polyhydride-bridged complexes: A DFT-based investigation","authors":"Abdelatif Messaoudi","doi":"10.1016/j.poly.2025.117909","DOIUrl":"10.1016/j.poly.2025.117909","url":null,"abstract":"<div><div>This study presents a comprehensive theoretical analysis of a series of bimetallic diruthenium complexes [Cp<sup>‡</sup>Ru(μ-H)<sub>3</sub>IrCp<sup>⁎</sup>], [Cp<sup>‡</sup>Ru(μ-H)<sub>3</sub>RhCp<sup>⁎</sup>], [Cp<sup>‡</sup>Ru (μ-H)<sub>3</sub>{Ru(p-cymene)}], [Cp<sup>‡</sup>Ru(μ-H)<sub>3</sub>{Ru(benzene)}] and [Cp<sup>‡</sup>Ru(μ-H)<sub>2</sub>(μ-Cl){Ru(p-cymene)}] (Cp* = C<sub>5</sub>Me<sub>5</sub>, Cp<sup>‡</sup> = C5<sup>t</sup>Bu<sub>3</sub>H<sub>2</sub>, p-cymene = CH<sub>3</sub>C<sub>6</sub>H<sub>4</sub>CH(CH<sub>3</sub>)<sub>2</sub>)) (A1-A5), incorporating various metal centers (Ir, Rh) and ligands (hydrides, chloride, Cp*) using density functional theory (DFT) at the B3LYP level with LanL2DZ and def2-TZVP basis sets. The geometric structures, electronic configurations, molecular orbitals, global reactivity descriptors, electrostatic potentials, atomic charges, TDOS, UV–Vis absorption spectra, and nonlinear optical (NLO) properties were systematically investigated. Geometry optimizations reveal excellent agreement with experimental data, with def2-TZVP offering slightly improved accuracy in metal-ligand bond distances and angles. The HOMO-LUMO gap analysis and frontier molecular orbitals show that complexes A1 and A5 have the narrowest gaps, indicating higher reactivity, while A3 displays the highest electron delocalization and charge transfer capability. Reactivity descriptors position A2 as the most electrophilic species, with high electronegativity and electron affinity, whereas A3 acts as the best donor. Molecular electrostatic potential (MESP) maps show distinct charge distributions and identify nucleophilic and electrophilic regions, highlighting the strong influence of ligand identity. Charge analysis supports significant polarization effects, particularly in A5 due to the chloride ligand. UV–Vis spectral simulations predict strong absorption in the visible region for A5, with metal to ligand charge transfer (MLCT) and π → π* transitions, indicating potential in photonic applications. Furthermore, NLO property analysis reveals that A3-A5 exhibit substantial hyperpolarizabilities, suggesting their promise as materials for second-order NLO applications. Altogether, this work underscores the sensitivity of electronic and optical properties to ligand environment, metal type, and computational treatment, offering valuable guidance for the design of functional organometallic complexes in catalysis, optoelectronics, and molecular electronics.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"285 ","pages":"Article 117909"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145652072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-19DOI: 10.1016/j.poly.2025.117892
Feng-Li Chen , Ao-Na Sun , Jiong Yang , Bo Chen , Jiang-Ping Qin , Dong Shao
A metal hydrogen-bonded organic frameworks (MHOFs) constructed from a 1D Fe(II) coordination polymer, {[Fe(bpy)·(H2O)4]·2ClO4·2bpy·2H2O}n (Fe, bpy = 4,4’-Bipyridine) was structurally, magnetically, and electrically characterized. Structural analysis indicates the presence of a high content of coordinated water and lattice water molecules, which form multiple hydrogen-bonded interactions with perchlorate anions and free bpy ligands. Combining the intermolecular π–π stacking interactions, a 3D supramolecular framework was formed. Magnetic measurements reveal high spin of the Fe2+ ions in FeHOF, in conjunction with variable-temperature single-crystal X-ray diffraction analysis. In addition, weak antiferromagnetic interaction between the Fe2+ ions transferred by bpy (J = −1.3 cm−1) was evidenced. Electrochemical impedance spectroscopy (EIS) indicates the FeHOF temperature and -humidity dependent proton conduction behavior through a vehicle mechanism (Ea = 0.45 eV). The highest observed conductivity was 6.2 × 10−5 S·cm−1 at 60 °C under 95% RH, indicating a supramolecular proton conductor of the FeHOF. The foregoing results not only provide a new proton-conducting MHOF material but also a promising way to construct proton-conducting MHOFs via a coordination chain approach
{"title":"Synthesis, structure, magnetic property, and proton conduction of a hydrogen-bonded framework assembled from Fe(II) coordination chains","authors":"Feng-Li Chen , Ao-Na Sun , Jiong Yang , Bo Chen , Jiang-Ping Qin , Dong Shao","doi":"10.1016/j.poly.2025.117892","DOIUrl":"10.1016/j.poly.2025.117892","url":null,"abstract":"<div><div>A metal hydrogen-bonded organic frameworks (MHOFs) constructed from a 1D Fe(II) coordination polymer, {[Fe(bpy)·(H<sub>2</sub>O)<sub>4</sub>]·2ClO<sub>4</sub>·2bpy·2H<sub>2</sub>O}<sub>n</sub> (<strong>Fe</strong>, bpy = 4,4’-Bipyridine) was structurally, magnetically, and electrically characterized. Structural analysis indicates the presence of a high content of coordinated water and lattice water molecules, which form multiple hydrogen-bonded interactions with perchlorate anions and free bpy ligands. Combining the intermolecular π–π stacking interactions, a 3D supramolecular framework was formed. Magnetic measurements reveal high spin of the Fe<sup>2+</sup> ions in FeHOF, in conjunction with variable-temperature single-crystal X-ray diffraction analysis. In addition, weak antiferromagnetic interaction between the Fe<sup>2+</sup> ions transferred by bpy (<em>J</em> = −1.3 cm<sup>−1</sup>) was evidenced. Electrochemical impedance spectroscopy (EIS) indicates the FeHOF temperature and -humidity dependent proton conduction behavior through a vehicle mechanism (<em>E</em><sub>a</sub> = 0.45 eV). The highest observed conductivity was 6.2 × 10<sup>−5</sup> S·cm<sup>−1</sup> at 60 °C under 95% RH, indicating a supramolecular proton conductor of the FeHOF. The foregoing results not only provide a new proton-conducting MHOF material but also a promising way to construct proton-conducting MHOFs via a coordination chain approach</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"284 ","pages":"Article 117892"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-13DOI: 10.1016/j.poly.2025.117886
Deepa Krishnan, Angappan Sheela
This study outlines the synthesis, comprehensive characterisation, and assessment of anticancer efficacy of three mononuclear aldimine-based nickel, copper, and zinc complexes. The complexes are characterised by FTIR, UV–Vis, 1H, 13C NMR, EPR, and HR-MS spectral techniques. The 6-311G/LanL2DZ ECP basis set and the B3LYP optimise the molecular structures and geometries of the ligands and complexes. The UV absorption titration and fluorescence quenching experiments evaluate the relative binding propensity profiles of the compounds with DNA and BSA. From the results of the UV method, it has been observed that the nickel complex shows a stronger affinity with CT-DNA, having the intrinsic binding constant (Kb) of 9.26 × 105 M−1, than other complexes. However, in the competitive displacement assay with ethidium bromide, the copper complex, preferably, shows higher binding interactions, with the Stern-Volmer constant (Ksv) value of 4.4 × 103 M−1, than other complexes. In the fluorescence quenching assay with BSA, only the nickel complex shows a Stern-Volmer quenching constant (KBSA) value of 6.4401 × 104 M−1, higher than the other complexes. The molecular docking indicated that the compounds possess high binding energy, supporting the experimental observations. The pHarmacokinetics and drug-like behaviour of the compounds are ascertained theoretically by ADMET studies.
{"title":"Structural elucidation, nuclease activity, protein binding, docking, and ADMET studies of nickel, copper, and zinc complexes","authors":"Deepa Krishnan, Angappan Sheela","doi":"10.1016/j.poly.2025.117886","DOIUrl":"10.1016/j.poly.2025.117886","url":null,"abstract":"<div><div>This study outlines the synthesis, comprehensive characterisation, and assessment of anticancer efficacy of three mononuclear aldimine-based nickel, copper, and zinc complexes. The complexes are characterised by FTIR, UV–Vis, <sup>1</sup>H, <sup>13</sup>C NMR, EPR, and HR-MS spectral techniques. The 6-311G/LanL2DZ ECP basis set and the B3LYP optimise the molecular structures and geometries of the ligands and complexes. The UV absorption titration and fluorescence quenching experiments evaluate the relative binding propensity profiles of the compounds with DNA and BSA. From the results of the UV method, it has been observed that the nickel complex shows a stronger affinity with CT-DNA, having the intrinsic binding constant (K<sub>b</sub>) of 9.26 × 10<sup>5</sup> M<sup>−1</sup><sub>,</sub> than other complexes. However, in the competitive displacement assay with ethidium bromide, the copper complex, preferably, shows higher binding interactions, with the Stern-Volmer constant (K<sub>sv</sub>) value of 4.4 × 10<sup>3</sup> M<sup>−1</sup>, than other complexes. In the fluorescence quenching assay with BSA, only the nickel complex shows a Stern-Volmer quenching constant (K<sub>BSA</sub>) value of 6.4401 × 10<sup>4</sup> M<sup>−1</sup>, higher than the other complexes. The molecular docking indicated that the compounds possess high binding energy, supporting the experimental observations. The pHarmacokinetics and drug-like behaviour of the compounds are ascertained theoretically by ADMET studies.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"284 ","pages":"Article 117886"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-08DOI: 10.1016/j.poly.2025.117875
Shiva Kumar Saw , Sudipta Datta , Pavan K. Gupta , Binod Kumar , Prakash D. Chavan , Shweta Kumari , Gajanan Sahu , Nilesh D. Dhaigude
The Cu-based catalysts mainly accounted for the synthesis of methanol from synthesis gas. The promotion of Cu-based catalysts resulted in a significant increase in methanol selectivity, even with small quantities of an effective promoter. The CuZn system without promoter and with promoters such as Cerium (Ce), Gallium (Ga), and Zirconium (Zr) are induced in the CuZn system individually and studied their ease of Cu reduction. All four catalysts have been prepared via the coprecipitation method, and an experimental study has been carried out for syngas hydrogenation to methanol on a bench-scale fixed bed tubular reactor at 60 bar and 200 °C. The synthesized catalysts were characterized by multiple techniques, including Field Emission Scanning Electron Microscopy (FE-SAM), and Energy Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Temperature programmed reduction (TPR), Brunauer–Emmett–Teller (BET) surface area analyzer, X-ray fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), True Density-Porosity, Thermogravimetric Analysis (TGA), and the liquid product has been studied by Gas chromatography-FID and Karl fisher titrator. The determinantal effect of Ce, Ga, and Zr doping in the CuZn catalyst and their respective activity has been studied based on electronic, geometric, reaction kinetics, and acid/base surface properties. This paper has briefly deliberated on the syngas, mainly CO hydrogenation to methanol over each of the catalysts for 72 h as well as the space-time yield (STY) and methanol selectivity. The cause of significant improvements in activity and stability regarding STY of Ce-promoted CuZn catalyst over Ga and Zr promoted on the CuZn system has been elaborated. The Influence of Ce, Ga & Zr for higher active Cu dispersion on the catalyst surface to promote its activity towards methanol synthesis has been briefly annotated.
{"title":"The significant role of cerium, gallium, and zirconium in cu-based catalyst for syngas to methanol: a bench scale experimental approach","authors":"Shiva Kumar Saw , Sudipta Datta , Pavan K. Gupta , Binod Kumar , Prakash D. Chavan , Shweta Kumari , Gajanan Sahu , Nilesh D. Dhaigude","doi":"10.1016/j.poly.2025.117875","DOIUrl":"10.1016/j.poly.2025.117875","url":null,"abstract":"<div><div>The Cu-based catalysts mainly accounted for the synthesis of methanol from synthesis gas. The promotion of Cu-based catalysts resulted in a significant increase in methanol selectivity, even with small quantities of an effective promoter. The Cu<img>Zn system without promoter and with promoters such as Cerium (Ce), Gallium (Ga), and Zirconium (Zr) are induced in the Cu<img>Zn system individually and studied their ease of Cu reduction. All four catalysts have been prepared via the coprecipitation method, and an experimental study has been carried out for syngas hydrogenation to methanol on a bench-scale fixed bed tubular reactor at 60 bar and 200 °C. The synthesized catalysts were characterized by multiple techniques, including Field Emission Scanning Electron Microscopy (FE-SAM), and Energy Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Temperature programmed reduction (TPR), Brunauer–Emmett–Teller (BET) surface area analyzer, X-ray fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), True Density-Porosity, Thermogravimetric Analysis (TGA), and the liquid product has been studied by Gas chromatography-FID and Karl fisher titrator. The determinantal effect of Ce, Ga, and Zr doping in the Cu<img>Zn catalyst and their respective activity has been studied based on electronic, geometric, reaction kinetics, and acid/base surface properties. This paper has briefly deliberated on the syngas, mainly CO hydrogenation to methanol over each of the catalysts for 72 h as well as the space-time yield (STY) and methanol selectivity. The cause of significant improvements in activity and stability regarding STY of Ce-promoted Cu<img>Zn catalyst over Ga and Zr promoted on the Cu<img>Zn system has been elaborated. The Influence of Ce, Ga & Zr for higher active Cu dispersion on the catalyst surface to promote its activity towards methanol synthesis has been briefly annotated.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"284 ","pages":"Article 117875"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two new silver(I) complexes, {[Ag2(S-3Py)2(fumarate)]·2C2H5OH·2H2O}n (1) and [Ag2(S-4Py)2(fumarate)]·3C2H5OH (2), (S-3Py = bis[1-(pyridin-3-ylmethyl)-benzimidazol-2-ylmethyl]sulfane, S-4Py = bis[1-(pyridin-4-ylmethyl)-benzimidazol-2-ylmethyl]sulfane), were synthesized. Single-crystal structural analysis revealed that Complex 1 adopts a one-dimensional chain structure, while Complex 2 exhibits a discrete binuclear configuration. The difference of skeleton structure of silver(I) complexes is due to the steric hindrance of main ligands S-3Py and S-4Py. The electrochemical sensing performance of two silver(I) complexes modified glassy carbon electrodes (Ag-1@GCE and Ag-2@GCE) for hydrogen peroxide detection in 0.2 M PBS was studied by constant voltage chronoamperometry. The Ag-1@GCE and Ag-2@GCE sensors for H2O2 was realized with a good linear response over the concentration range from 0.5 μM to 4 mM, a detection limit of 0.136 μM and 0.214 μM (S/N = 3), high selectivity and short response time (< 3 s). Relative to Ag-2@GCE, Ag-1@GCE has better H2O2 recognition activity, which is attributed to the extensible one-dimensional structure and more electrocatalytic active sites of complex 1. Moreover, the two electrodes demonstrate high accuracy, with a recovery rate of 96.5 % -103.3 % for H2O2 detection. This paper provides a new method for the development of metal complex electrochemical sensors.
{"title":"Two electrochemical sensors based on different skeleton silver(I) complex modified glassy carbon electrodes for determination of H2O2","authors":"Rongrong Gao, Yuanyue Ma, Quanlong Cai, Junjie Teng, Huilu Wu","doi":"10.1016/j.poly.2025.117918","DOIUrl":"10.1016/j.poly.2025.117918","url":null,"abstract":"<div><div>Two new silver(I) complexes, {[Ag<sub>2</sub>(S-3Py)<sub>2</sub>(fumarate)]·2C<sub>2</sub>H<sub>5</sub>OH·2H<sub>2</sub>O}<sub>n</sub> (<strong>1</strong>) and [Ag<sub>2</sub>(S-4Py)<sub>2</sub>(fumarate)]·3C<sub>2</sub>H<sub>5</sub>OH (2), (S-3Py = bis[1-(pyridin-3-ylmethyl)-benzimidazol-2-ylmethyl]sulfane, S-4Py = bis[1-(pyridin-4-ylmethyl)-benzimidazol-2-ylmethyl]sulfane), were synthesized. Single-crystal structural analysis revealed that Complex <strong>1</strong> adopts a one-dimensional chain structure, while Complex <strong>2</strong> exhibits a discrete binuclear configuration. The difference of skeleton structure of silver(I) complexes is due to the steric hindrance of main ligands S-3Py and S-4Py. The electrochemical sensing performance of two silver(I) complexes modified glassy carbon electrodes (Ag-1@GCE and Ag-2@GCE) for hydrogen peroxide detection in 0.2 M PBS was studied by constant voltage chronoamperometry. The Ag-1@GCE and Ag-2@GCE sensors for H<sub>2</sub>O<sub>2</sub> was realized with a good linear response over the concentration range from 0.5 μM to 4 mM, a detection limit of 0.136 μM and 0.214 μM (S/N = 3), high selectivity and short response time (< 3 s). Relative to Ag-2@GCE, Ag-1@GCE has better H<sub>2</sub>O<sub>2</sub> recognition activity, which is attributed to the extensible one-dimensional structure and more electrocatalytic active sites of complex <strong>1</strong>. Moreover, the two electrodes demonstrate high accuracy, with a recovery rate of 96.5 % -103.3 % for H<sub>2</sub>O<sub>2</sub> detection. This paper provides a new method for the development of metal complex electrochemical sensors.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"285 ","pages":"Article 117918"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-17DOI: 10.1016/j.poly.2025.117933
N.S. Mohan , M. Pandian , A. Arulraj , R.V. Mangalaraja , V. Nithya Priya , V. Vijayalakshmi
In this work, we used an eco-friendly method to prepare nanosized CaTiO3, Ag@CaTiO3, and Sm@Ag@CaTiO3 NPs and studied how Ag and Sm influence their photocatalytic behavior. XRD analysis confirmed that all samples formed an orthorhombic perovskite structure, while microscopic observation showed that the particles were mostly spherical. UV–vis studies revealed that adding Ag and Sm improved the light-absorption ability of CaTiO3 by slightly narrowing its band gap, with Eg values of 3.37, 3.34, and 3.32 eV for CaTiO3, Ag@CaTiO3, and Sm@Ag@CaTiO3 respectively. Photocatalytic tests showed a clear enhancement in dye degradation after doping, and the Sm@Ag@CaTiO3 sample delivered the best performance, reaching about 73–76 % degradation compared to 66.56 % for pure CaTiO3. The enhancement observed can be attributed primarily to improved charge separation, a decrease in grain size, and increased surface activity resulting from the synergistic influence of Ag and Sm. The findings indicate that Sm@Ag@CaTiO3 presents a viable and economical option as a photocatalyst for the treatment of dye-contaminated wastewater.
{"title":"Facile green synthesis of CaTiO3, Ag@CaTiO3 and Sm@Ag@CaTiO3 NPs using soursop leaf extract and its enhanced catalytic properties","authors":"N.S. Mohan , M. Pandian , A. Arulraj , R.V. Mangalaraja , V. Nithya Priya , V. Vijayalakshmi","doi":"10.1016/j.poly.2025.117933","DOIUrl":"10.1016/j.poly.2025.117933","url":null,"abstract":"<div><div>In this work, we used an eco-friendly method to prepare nanosized CaTiO<sub>3</sub>, Ag@CaTiO<sub>3</sub>, and Sm@Ag@CaTiO<sub>3</sub> NPs and studied how Ag and Sm influence their photocatalytic behavior. XRD analysis confirmed that all samples formed an orthorhombic perovskite structure, while microscopic observation showed that the particles were mostly spherical. UV–vis studies revealed that adding Ag and Sm improved the light-absorption ability of CaTiO<sub>3</sub> by slightly narrowing its band gap, with Eg values of 3.37, 3.34, and 3.32 eV for CaTiO<sub>3</sub>, Ag@CaTiO<sub>3</sub>, and Sm@Ag@CaTiO<sub>3</sub> respectively. Photocatalytic tests showed a clear enhancement in dye degradation after doping, and the Sm@Ag@CaTiO<sub>3</sub> sample delivered the best performance, reaching about 73–76 % degradation compared to 66.56 % for pure CaTiO<sub>3</sub>. The enhancement observed can be attributed primarily to improved charge separation, a decrease in grain size, and increased surface activity resulting from the synergistic influence of Ag and Sm. The findings indicate that Sm@Ag@CaTiO<sub>3</sub> presents a viable and economical option as a photocatalyst for the treatment of dye-contaminated wastewater.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"285 ","pages":"Article 117933"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-17DOI: 10.1016/j.poly.2025.117898
Zhen-Yu Yang, Jia-Lu Guan, Jin-Sheng Zhang, Ju-Wen Zhang, Yan Zhao, Bin-Qiu Liu
In this paper, a series of Ni(II)-Ln(III) heterometallic complexes [Ln2Ni2(2,3-DCB)10(4,4′-dm-2,2′-bpy)2] [Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6), Yb (7), 2,3-HDCB = 2,3-dichlorobenzoic acid, 4,4′-dm-2,2′-bpy = 4,4′-dimethyl-2,2′-bipyridine] were solvothermally synthesized and structurally characterized. Complexes 1–7 have the same molecular formula but different molecular structures. Complexes 1–6 are isostructural. Complexes 1–7 all show zero-dimensional (0D) linear tetranuclear cluster structures, and the adjacent molecules can be linked through the π–π interactions between 4,4′-dm-2,2′-bipy into a one-dimensional (1D) supramolecular chain. Complex 6 exhibits the ferromagnetic couplings between the metal ions and obvious field-dependent single-molecule magnet (SMM) behavior with an effective energy barrier (Ueff) of approximately 13 K. Introduction of two methyl groups in 2,2′-bipy has an important effect on the structures and magnetic properties of Ni(II)-Ln(III) heterometallic complexes.
{"title":"Syntheses, structures and magnetic properties of a series of nickel-lanthanide heterometallic complexes with mixed ligands of 2,3-dichlorobenzoate and 4,4′-dimethyl-2,2′-bipyridine","authors":"Zhen-Yu Yang, Jia-Lu Guan, Jin-Sheng Zhang, Ju-Wen Zhang, Yan Zhao, Bin-Qiu Liu","doi":"10.1016/j.poly.2025.117898","DOIUrl":"10.1016/j.poly.2025.117898","url":null,"abstract":"<div><div>In this paper, a series of Ni(II)-Ln(III) heterometallic complexes [Ln<sub>2</sub>Ni<sub>2</sub>(2,3-DCB)<sub>10</sub>(4,4′-dm-2,2′-bpy)<sub>2</sub>] [Ln = Nd (<strong>1</strong>), Sm (<strong>2</strong>), Eu (<strong>3</strong>), Gd (<strong>4</strong>), Tb (<strong>5</strong>), Dy (<strong>6</strong>), Yb (<strong>7</strong>), 2,3-HDCB = 2,3-dichlorobenzoic acid, 4,4′-dm-2,2′-bpy = 4,4′-dimethyl-2,2′-bipyridine] were solvothermally synthesized and structurally characterized. Complexes <strong>1</strong>–<strong>7</strong> have the same molecular formula but different molecular structures. Complexes <strong>1</strong>–<strong>6</strong> are isostructural. Complexes <strong>1</strong>–<strong>7</strong> all show zero-dimensional (0D) linear tetranuclear cluster structures, and the adjacent molecules can be linked through the π–π interactions between 4,4′-dm-2,2′-bipy into a one-dimensional (1D) supramolecular chain. Complex <strong>6</strong> exhibits the ferromagnetic couplings between the metal ions and obvious field-dependent single-molecule magnet (SMM) behavior with an effective energy barrier (<em>U</em><sub>eff</sub>) of approximately 13 K. Introduction of two methyl groups in 2,2′-bipy has an important effect on the structures and magnetic properties of Ni(II)-Ln(III) heterometallic complexes.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"284 ","pages":"Article 117898"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-17DOI: 10.1016/j.poly.2025.117894
Muhammad Tariq Nadeem , M.I. Khan , Ali Mujtaba , Merfat S. Al-Sharif , Dalia I. Saleh , M.N. Khan
The significance of this study lies in addressing the urgent need for sustainable solutions to mitigate dye-contaminated wastewater. This work presents a novel green-synthesized CuWO₄@SnWO₄ nanocomposite using Aloe vera extract via hydrothermal method for enhanced photocatalytic degradation of methylene blue (MB) under visible light. Structural analysis via XRD confirmed the formation of a monoclinic CuWO₄@SnWO₄ phase with an average crystallite size of 29.11 nm, indicating high crystallinity and defect-induced strain. FTIR spectra verified the presence of characteristic WO, CuO, and SnO vibrational bands, validating the composite's structural integrity. SEM revealed interconnected, irregular flake-like morphologies with particle sizes centered around 47 μm, promoting higher surface area and charge transfer. Electrochemical characterizations using CV and EIS demonstrated strong redox activity and low charge transfer resistance (1.09 Ω), confirming efficient charge separation and mobility. UV–vis spectroscopy showed strong absorption in the visible range with a narrow band gap of 2.23 eV. Photocatalytic experiments exhibited remarkable degradation efficiency of 91 % for MB within 135 min, following zero-order kinetics. This highlights the composite's applicability for wastewater treatment. Future studies can further optimize morphology and explore other green precursors to expand practical deployment in environmental remediation.
{"title":"Improving the photocatalytic properties of metal tungsten oxide heterostructure prepared by the green hydrothermal method","authors":"Muhammad Tariq Nadeem , M.I. Khan , Ali Mujtaba , Merfat S. Al-Sharif , Dalia I. Saleh , M.N. Khan","doi":"10.1016/j.poly.2025.117894","DOIUrl":"10.1016/j.poly.2025.117894","url":null,"abstract":"<div><div>The significance of this study lies in addressing the urgent need for sustainable solutions to mitigate dye-contaminated wastewater. This work presents a novel green-synthesized CuWO₄@SnWO₄ nanocomposite using <em>Aloe vera</em> extract via hydrothermal method for enhanced photocatalytic degradation of methylene blue (MB) under visible light. Structural analysis via XRD confirmed the formation of a monoclinic CuWO₄@SnWO₄ phase with an average crystallite size of 29.11 nm, indicating high crystallinity and defect-induced strain. FTIR spectra verified the presence of characteristic W<img>O, Cu<img>O, and Sn<img>O vibrational bands, validating the composite's structural integrity. SEM revealed interconnected, irregular flake-like morphologies with particle sizes centered around 47 μm, promoting higher surface area and charge transfer. Electrochemical characterizations using CV and EIS demonstrated strong redox activity and low charge transfer resistance (1.09 Ω), confirming efficient charge separation and mobility. UV–vis spectroscopy showed strong absorption in the visible range with a narrow band gap of 2.23 eV. Photocatalytic experiments exhibited remarkable degradation efficiency of 91 % for MB within 135 min, following zero-order kinetics. This highlights the composite's applicability for wastewater treatment. Future studies can further optimize morphology and explore other green precursors to expand practical deployment in environmental remediation.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"285 ","pages":"Article 117894"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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